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Genus Rhyssoplax Thiele, 1893 Type species. Chiton affinis Issel, 1869, by subsequent designation (International Committee of Zoological Nomenclature 1971, Opinion 951, as proposed by Beu et al. 1969). Remarks. The genus Chiton was subdivided into numerous subgenera by Kaas et al. (2006), some of which (e.g. Rhyssoplax Thiele, 1893) were promoted to full genus rank by Sirenko (2006), based mainly on soft part morphology. Distribution. Tropical and subtropical waters of the Indo-Pacific (except for the East Pacific), also in the Eastern Atlantic. The fossil record extends back to the Oligocene of New Zealand (Dell���Angelo et al. 2011a), the Neogene of Europe (Dell���Angelo et al. 2004, 2015; Garilli et al. 2005; Studencka & Dulai 2010), Africa (Algeria: De Lamothe 1911; Tunisia: Castany et al. 1956), New Zealand (Beu & Maxwell 1990) and Japan (Itoigawa et al. 1976)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on page 412, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Thiele, J. (1893) Das Gebiss der Schecken zur Begrundung einer naturlichen Classification. In: Troschel, F. H., Polyplacophora, Lepidoglossa, Schuppenzungler, Berlin, 2, 353 - 401, pls. 30 - 32.","Issel, A. (1869) Malacologia del Mar Rosso. Ricerche zoologiche e paleontologiche. Parte terza. Catalogo delle conchiglie fossili raccolte sulle spiagge emerse del Mar Rosso. Biblioteca Malacologica, Pisa, 61 pp. [pp. 243 - 303]","Beu, A. G., Dell, R. K. & Fleming, C. A. (1969) Rhyssoplax Thiele, 1893 (Mollusca, Amphineura): request for designation of a type-species under the plenary powers. Bulletin of Zoological Nomenclature, 25, 184 - 185.","Kaas, P., Van Belle, R. A. & Strack, H. L. (2006) Monograph of Living Chitons (Mollusca: Polyplacophora). Volume 6. Suborder Ischnochitonina (concluded): Schizochitonidae; Chitonidae. Additions to Volumes 1 - 5. E. J. Brill, Leiden-Boston, 463 pp.","Sirenko, B. I. (2006) New outlook on the system of chitons (Mollusca: Polyplacophora). Venus, 65, 27 - 49.","Dell'Angelo, B., Bonfitto, A. & Taviani, M. (2011 a) Chitons (Polyplacophora) from Paleogene strata in Western Washington State, U. S. A. Journal of Paleontology, 85, 936 - 954. https: // doi. org / 10.1666 / 10 - 114.1","Dell'Angelo, B., Bonfitto, A., Sabelli, B. & Taviani, M. (2004) Chitons (Mollusca, Polyplacophora) from bioclastic sands of the Ifaty-Tulear back reefs (Madagascar, Western Indian Ocean). Bollettino Malacologico, Supplment 5, 45 - 62.","Dell'Angelo, B., Giuntelli, P., Sosso, M. & Zunino, M. (2015) Polyplacophora from the Miocene of North Italy. Part 1: Leptochitonidae, Hanleyidae, Ischnochitonidae and Callistoplacidae. Rivista Italiana di Paleontologia e Stratigrafia, 121, 217 - 242.","Garilli, V., Dell'Angelo, B. & Vardala-Theodorou, E. (2005) Polyplacophora from the Pleistocene of Kyllini (NW Peloponnese, Greece). Bollettino della Societa Paleontologica Italiana, 44, 117 - 134.","Studencka, B. & Dulai, A. (2010) Chitons (Mollusca: Polyplacophora) from the Middle Miocene sandy facies of Ukraine, Central Paratethys. Acta Geologica Polonica, 60, 257 - 274.","De Lamothe (1911) Les anciennes lignes de rivage du Sahel d'Alger et d'une part de la cote algerienne. Memoires de la Societe geologique de France, Series 4, 1 (6), 1 - 288.","Castany, G., Gobert, G. & Harson, L. (1956) Le Quaternaire marin de Monastir. Annales Mines and Geology, 19, 1 - 58, 2 pls.","Beu, A. G. & Maxwell, P. A. (1990) Cenozoic Mollusca of New Zealand. New Zealand Geological Survey Paleontological Bulletin, 58, 1 - 518.","Itoigawa, J., Kuroda, M., Naruse, A. & Nishimoto, H. (1976) Polyplacophora assemblages from the Pleistocene formations of Boso and Miura Peninsulas, environs of Tokyo, Japan. Bulletin of the Mizunami Fossil Museum, 3, 171 - 204."]}

Lucilina colantonii n. sp. (Fig. 15) Type material. Holotype: MZB 50549, intermediate valve, width 2.7 mm (Figs 15 A–C). Paratype: RGM.1356860, intermediate valve, width 3.9 mm (Figs 15 D–F). Type locality. Hurghada, Egypt (St. 16). Other material examined. Egypt, Hurghada: St. 13: 2 intermediate valves (BD 213); St. 14: 2 intermediate valves (BD 214); St. 16: 1 intermediate valve (BD 215). Recent material examined. Sudan, Shab Runi Reef (P078): 2 intermediate valves, Figs 15 J–L (BD 216, MZB 50551); Sudan, Sanganeb Reef (D08): 1 intermediate valve (MZB 60260); Egypt, Gulf of Aqaba (P447): 4 intermediate valves, Figg 15 G–I (BD 217; MZB 50550); Egypt, Gulf of Aqaba, Blue Hole (P447A): 1 intermediate valve (BD 218). Maximum width of the intermediate valves: 5.5 mm. Type stage. Late Pleistocene, last interglacial MIS5e. Etymology. This species honours the marine geologist Paolo Colantoni (1934–2015) who first introduced M.T. to the study of recent and fossil molluscs of the Gulf of Aqaba. Diagnosis. Intermediate valve rectangular, moderately elevated, semicarinate in anterior profile, posterior margin almost straight at both sides of prominent apex, almost triangular, pleural areas with longitudinal regular striae of small, roundish granules, jugal area large, smooth, lateral areas not raised, with irregular radial striae of similar granules. Articulamentum white, apophyses small, triangular, jugal sinus wide, one slit, teeth finely grooved on upper side. Description. Intermediate valve rectangular, L/W ratio = 0.53–0.63, anterior margin convex, moderately elevated (H/W = 0.36–0.41), semicarinate in anterior profile, side margins slightly rounded, posterior margin almost straight at both sides of prominent apex, almost triangular, forming an angle of ca 120–130°, pleural areas with longitudinal and enough regular striae of small, roundish granules, ca 10–12 on each side, with reduced spaces between the striae of granules, jugal area large, smooth, lateral areas not raised, with 6–7 irregular radial striae of similar granules, ocelli scarcely visible in anterior third. Granules of longitudinal striae entirely covered by aesthetes of the same dimensions, not regularly arranged. Articulamentum white, apophyses small, triangular, jugal sinus wide, one slit, slit rays not indicated, teeth finely grooved on upper side. Remarks. Only poorly preserved and often incomplete intermediate valves are present in the studied material. The species is similar to Lucilina aegyptiaca n. sp., from which it differs in several characters (Tab. 3). The distribution of the aesthetes on the granules of the longitudinal striae is unusual, they are of the same di- mensions and arranged without a particular order, in contrast to the norm (generally with one or more central macroaesthetes and several microaesthetes arranged along the edge of the granule). Numerous valves of Lucilina colantonii n.sp. were identified in extant Red Sea material still unpublished, mixed in samples initially labeled L. sueziensis and L. perligera. Two such valves are illustrated for comparison (Fig. 15 G–L). No significant differences appear between extant and fossil valves. The extant valves are well preserved and show additional characters not preserved in the fossil state, namely the presence of longitudinal striae of small roundish granules with a diameter up to 60 µm, and ocelli with a diameter of 33–37 µm. Distribution. Late Pleistocene: Egypt (Hurghada: this study). Present-day (this study): Sudan, Sha’ab Rum Reef, Sanganeb Reef; Egypt, Gulf of Aqaba (Blue Hole).

Genus Cryptoplax Blainville, 1818 Type species. Chiton larvaeformis Burrow, 1815, by subsequent designation (Gray 1821: 234). Remarks. Cryptoplax occurs in tropical and subtropical waters of the Indo-Pacific. The genus extends back to the Miocene of Italy and Paratethys (Dell���Angelo et al. 2016; Dulai 2005), Indonesia, Fiji (Schwabe et al. 2008) and West Pacific Islands (Ladd 1966)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on page 437, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Blainville, H. M. D. de (1818) Cryptoplax. In: Cuvier, F. (Ed.), Dictionnaire des Sciences Naturelles. Vol. 12. F. G. Levrault, Strasbourg and Le Normant, Paris, pp. 124.","Burrow, E. J. (1815) Elements of Conchology, according to the Linnean System. J. Duncan, London, xix + 245 pp., 28 pls. https: // doi. org / 10.5962 / bhl. title. 11498","Gray, J. E. (1821) A natural arrangement of Mollusca, according to their internal structure. The London Medical Repository, 15, 229 - 239.","Dell'Angelo, B., Giuntelli, P., Sosso, M. & Zunino, M. (2016) Polyplacophora from the Miocene of North Italy. Part 2: Callochitonidae, Chitonidae, Lepidochitonidae, Acanthochitonidae and Cryptoplacidae. Rivista Italiana di Paleontologia e Stratigrafia, 122, 23 - 54.","Dulai, A. (2005) Badenian (Middle Miocene) Polyplacophora from the Central Paratethys (Band and Devecser, Bakony Mountains, Hungary). Fragmenta Palaeontologica Hungarica, 23, 29 - 50.","Schwabe, E., Sirenko, B. I. & Seeto, J. (2008) A checklist of Polyplacophora (Mollusca) from the Fiji Islands. Zootaxa, 1777 (1), 1 - 52. https: // doi. org / 10.11646 / zootaxa. 1777.1.1","Ladd, H. S. (1966) Chitons and Gastropods (Haliotidae through Adeorbidae) from the western Pacific islands. Geological Survey Professional Paper, 531, 1 - 98, 16 pls. https: // doi. org / 10.3133 / pp 531"]}

Craspedochiton sp. (Fig. 21) Craspedochiton (Notoplax) involutus; Selli 1973, p. 257, pl. 11, figs 6���7. Material examined. Eritrea, Massawa North (Abd-el-Cader): 2 valves (1 intermediate, width 3.3 mm, and 1 tail, width 3.7 mm), described and illustrated by Selli, 1973 (Fig. 21A, not seen at MGGC). Egypt, Hurghada: St. 14bis: 1 intermediate valve, width 1,4 mm (Figs 21 B���C) (MZB 50561); St. 16: 1 intermediate valve, width 3 mm (Figs 21 D���E) (MZB 50562). Remarks. Selli (1973) recorded Craspedochiton from Massawa based on one intermediate and one posterior valve (Fig. 21A). The attribution of this material to Craspedochiton (Notoplax) involutus was based on the similarity of the shape of the valves figured by Pilsbry (1893, vol. XV: 35, pl. 1, figs 27���35). Craspedochiton involutus was synonymised with C. productus (Carpenter in Pilsbry, 1892) by Kaas (1989), a species characterised by having intermediate and tail valves of trapezoidal shape. These valves of Craspedochiton productus differ significantly from those figured by Selli (compare with the valves of a specimen of C. productus from S. Africa figured by Dell���Angelo et al. 2014: figs 8A���F). A search for Selli���s (1973) material in MGGC was unsuccessful and we consider that this material is probably lost. We suspect that the intermediate valve (worn and without any diagnostic feature) might not belong to Craspedochiton. The only extant species of Craspedochiton present in the Red Sea is C. laqueatus (Sowerby, 1842) (Strack 1993; Anseeuw & Terryn 2004), a widespread Indo-Pacific species known from the northern Red Sea to the Philippines, whose type material was recently figured by Dell���Angelo et al. (2010a: figs 10A���F, 12M���Q). The valves figured by Selli (1973) differ from those of C. laqueatus in the shape of the valves and the position of the mucro (���somewhat anteriorly��� in C. laqueatus, Strack 1993 vs much more posteriorly in in Selli���s figures). We have collected two small and eroded intermediate fossil valves (Figs 21 B���E), without any diagnostic feature, of which only the presence of large granules could justify the attribution to the genus Craspedochiton. For the reasons discussed above, and considering that we could not find the specimens figured by Selli in MGGC, species identification for the valves here discussed is impossible. Craspedochiton species from the Indian Ocean are a difficult group to understand, due to scarcity of the material available, the high variability of the species, and the often inadequate original description (see discussions by Kaas (1979) and Schwabe & Els (2019) on C. isipingoensis (Sykes, 1901), by Schwabe (2006) on C. tetrica (Carpenter in Pilsbry, 1893)).. Distribution. Late Pleistocene: Eritrea, Massawa North (Abd-el-Cader); Egypt (Hurghada: Selli 1973; this study)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on pages 434-435, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Selli, R. (1973) Molluschi quaternari di Massaua e di Gibuti. In: Accademia Nazionale dei Lincei. Missione Geologica dell'AGIP nella Dancalia meridionale e sugli Altipiani Ararini 1936 - 1938. Vol. IV. Parte Seconda. Documentazione Paleontologica, Roma, pp. 153 - 444, 30 pls.","Pilsbry, H. A. (1892 - 1894) Monograph of Polyplacophora. In: Tryon, G. W., Manual of Conchology. Vol. 15 & 16. Academy of Natural Sciences, Philadelphia, pp. 1 - 128, pls. 1 - 30 (1892) + pp. i-xxxiv, 129 - 350, pls. 31 - 68 (1893) & pp. 1 - 64, pls. 1 - 10 (1893) + pp. 65 - 133, pls. 11 - 17 (1894).","Kaas, P. (1989) Chitons (Mollusca, Polyplacophora) procured by the MUSORSTOM 3, Philippines expedition (1985). In: Forest, J., Resultats des Campagnes MUSORSTOM. Vol. 4. Memoires du Museum national d'Histoire naturelle, (A), 143, pp. 105 - 111.","Dell'Angelo, B., Schwabe, E., Gori, S., Sosso, M. & Bonfitto, A. (2014) Chitons (Mollusca, Polyplacophora) from Sao Tome and Principe Islands. African Invertebrates, 55, 171 - 200.","Sowerby, G. B. II (1842) Descriptions of four species of the genus Chiton, brought by H. Cuming, Esq., from the Philippine Islands. Proceedings of the Zoological Society of London, 9 (1841), 103 - 104.","Strack, H. L. (1993) The Polyplacophora of the Red Sea. Journal of the Malacological Society of Australia, 14, 1 - 40. https: // doi. org / 10.1080 / 00852988.1993.11923901","Anseeuw, B. & Terryn, Y. (2004) Intertidal chitons (Mollusca: Polyplacophora) from the coast of Jordan, Red Sea, with the description of a new species of Parachiton Thiele, 1909. Bollettino Malacologico, Supplement 5, 1 - 24.","Dell'Angelo, B., Gori, S., Baschieri, L. & Bonfitto, A. (2010 a) Chitons (Mollusca, Polyplacophora) from the Maldive islands. Zootaxa, 2673 (1), 1 - 38. https: // doi. org / 10.11646 / zootaxa. 2673.1.1","Kaas, P. (1979) The Chitons (Mollusca: Polyplacophora) of Mozambique. Annals of the Natal Museum, 23, 855 - 879.","Schwabe, E. & Els, R. (2019) The genus Craspedochiton (Mollusca: Polyplacophora: Acanthochitonidae) in South African waters: what do we really know about it? Archiv fur Molluskenkunde, 148, 73 - 92. https: // doi. org / 10.1127 / arch. moll / 148 / 073 - 092","Sykes, E. R. (1901) Description of Onithochiton (?) isipingoensis nov. spec. from South Africa. Proceedings of the Malacological Society of London, 4, 259."]}

Genus Lucilina Dall, 1882 Type species. Chiton confossus Gould, 1846 (= Chiton lamellosus Quoy & Gaimard, 1835), by subsequent designation (Pilsbry 1893). Remarks. Following the suggestions of some authors (e.g., Strack 2003; Schwabe 2004, 2006; Schwabe et al. 2008; Schwabe & Pittman 2014), the genus Lucilina is here used at full genus level, and not as a subgenus of Tonicia Gray, 1847. The species of Tonicia are geographically restricted to the South Eastern Pacific region of Latin America with a single species in the Caribbean, while members of Lucilina are widespread throughout the tropical Indo-Pacific. Lucilina is well represented in the Indian Ocean by six species, L. sueziensis (Reeve, 1847), L. perligera Thiele, 1909, L. pectinoides (Sykes, 1903), L. ceylonica (Leloup, 1936), L. carnosa (Kaas, 1979) and L. indica (Leloup, 1981), of which only the first two are known from the Red Sea. Distribution. Widespread in the Indian Ocean, the Indo-Pacific, Australia, the Central Pacific Ocean and Japan. The fossil record extends back to the middle Oligocene of France, Aquitaine Basin (Dell���Angelo et al. 2018a), the Neogene of west Pacific islands (Ladd 1966; Schwabe et al. 2008) and the Pleistocene of the Red Sea (Issel 1869)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on page 415, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Dall, W. H. (1882) On the genera of chitons. Proceedings of the United States National Museum, 4, 279 - 291. https: // doi. org / 10.5479 / si. 00963801.4 - 228.279","Gould, A. A. (1846) On the shells collected by the United States Exploring Expedition, commanded by Charles Wilkes, U. S. N. Proceedings of the Boston Society of Natural History, 2 (14), 141 - 145. https: // doi. org / 10.5962 / bhl. part. 3318","Quoy, J. R. C. & Gaimard, J. P. (1835) Voyage de decouvertes de l' \" Astrolabe \". Execute par ordre du Roi, pendant les annees 1826 - 1827 - 1928 - 1829, sous le commandement de M. J. Dumont d'Urville. Zoologie 3, Mollusques, Genre Oscabrion. J. Tastu, Paris, 43 pp., pls. 73 - 75. [pp. 369 - 411]","Pilsbry, H. A. (1892 - 1894) Monograph of Polyplacophora. In: Tryon, G. W., Manual of Conchology. Vol. 15 & 16. Academy of Natural Sciences, Philadelphia, pp. 1 - 128, pls. 1 - 30 (1892) + pp. i-xxxiv, 129 - 350, pls. 31 - 68 (1893) & pp. 1 - 64, pls. 1 - 10 (1893) + pp. 65 - 133, pls. 11 - 17 (1894).","Strack, H. L. (2003) Class Polyplacophora. In: Hylleberg, J. & Kilburn, R. N. (Eds.), Tropical Marine Mollusc Programme. Marine Molluscs of Vietnam. Phuket Marine Biological Center Special Publication, 28, pp. 12 - 15.","Schwabe, E. (2004) The Polyplacophora (Mollusca) collected during the First International Marine Biodiversity Workshop for Rodrigues (western Indian Ocean), with the description of a new species. Journal of Natural History, 38, 3143 - 3173. https: // doi. org / 10.1080 / 00222930410001695114","Schwabe, E., Sirenko, B. I. & Seeto, J. (2008) A checklist of Polyplacophora (Mollusca) from the Fiji Islands. Zootaxa, 1777 (1), 1 - 52. https: // doi. org / 10.11646 / zootaxa. 1777.1.1","Schwabe, E. & Pittman, C. (2014) New records of chitons (Mollusca: Polyplacophora) from Hawaii, including the description of a new species of Weedingia Kaas, 1988. Venus, 72, 49 - 64.","Gray, J. E. (1847) A list of the genera of Recent Mollusca, their synonyms and types. Proceedings of the Zoological Society of London, 15, 129 - 206. https: // doi. org / 10.1111 / j. 1469 - 7998.1847. tb 00164. x","Reeve, L. (1847) Conchologia iconica, or illustrations of the shells of molluscous animals. Monograph of the genus Chiton. Vol. 4. Reeve, Brothers, London, 64 pp., 28 pls. [pp. 21 - 84]","Thiele, J. (1909) Revision des Systems der Chitonen. Zoologica, 22, 1 - 132, pls. 1 - 10. https: // doi. org / 10.5962 / bhl. title. 11245","Sykes, E. R. (1903) Report on the Polyplacophora collected by Professor Herdman, at Ceylon, in 1902. Ceylon Pearl Oyster Fisheries, Supplementary Reports, 4, 177 - 180, pl. 1.","Leloup, E. (1936) Descriptions de deux especes d'amphineures provenant de Trincomali (Ceylon). Proceedings of the Malacological Society of London, 22 (2), 51 - 61.","Kaas, P. (1979) The Chitons (Mollusca: Polyplacophora) of Mozambique. Annals of the Natal Museum, 23, 855 - 879.","Leloup, E. (1981) Chitons de Tulear, Reunion, Maurice et Tahiti. Bulletin Institut Royale des Sciences Naturelles de Belgique, 53, 1 - 46, 4 pls.","Dell'Angelo, B., Lesport, J. - F., Cluzaud, A. & Sosso, M. (2018 a) The Oligocene to Miocene chitons (Mollusca: Polyplacophora) of the Aquitaine Basin, southwestern France, and Ligerian Basin, western France. Part 1: Leptochitonidae, Hanleyidae, Ischnochitonidae, Chitonidae, Spinochitonidae fam. nov. and Schizochitonidae. Bollettino Malacologico, 54, 1 - 47.","Ladd, H. S. (1966) Chitons and Gastropods (Haliotidae through Adeorbidae) from the western Pacific islands. Geological Survey Professional Paper, 531, 1 - 98, 16 pls. https: // doi. org / 10.3133 / pp 531","Issel, A. (1869) Malacologia del Mar Rosso. Ricerche zoologiche e paleontologiche. Parte terza. Catalogo delle conchiglie fossili raccolte sulle spiagge emerse del Mar Rosso. Biblioteca Malacologica, Pisa, 61 pp. [pp. 243 - 303]"]}

Lucilina aqabaensis n. sp. (Fig. 13) Type material. Holotype: MZB 50545, a tail valve, St. 9, width 6.5 mm (Figs 13 A–F). Type locality. Gulf of Aqaba, Saudi Arabia (Ash Shaykh Humayd: this study): St. 9. Type stage. Late Pleistocene, last interglacial MIS5e. Etymology. The name refers to the Gulf of Aqaba, source of the material here described. Diagnosis. Tail valve semioval, mucro posterior, obtuse, antemucronal slope slightly convex, postmucronal slope perpendicular. Tegmentum finely granulose, antemucronal and postmucronal areas with concentric growth lines, characterised by the presence of groups of fused granules, irregularly arranged in concentric striae. Articulamentum white, apophyses well developed, jugal sinus wide, 10 slits, teeth slightly forwardly directed, finely grooved on upper side. Description. Tail valve semioval, length less than half width (L/W = 0.42), front margin straight, hind margin angularly rounded, mucro posterior, obtuse, antemucronal slope slightly convex, postmucronal slope perpendicular. Tegmentum finely granulose, roundish granules irregularly dispersed, extending over entire surface of valve, both antemucronal and postmucronal areas with concentric growth lines, characterised by the presence of groups of fused granules, more frequent and larger in postmucronal area along hind margin, giving the impression of being irregularly arranged in concentric striae. Roundish granules small and close-set, diameter ca 48–60 µm, with 1 large central macroaesthete and up to 10 microaesthetes along margin. Articulamentum white, apophyses well developed, jugal sinus wide, provided with a short plate, 10 slits, slit rays not indicated, teeth relatively long, slightly forwardly directed, all teeth finely grooved on upper side, denticulated on outer edge, eaves narrow, solid. Remarks. We assign this unique tail valve to the genus Lucilina based on the presence of having grooved teeth on the articulamentum (and not a callus as in the genus Onithochiton Gray, 1847), and having the mucro subterminal (and not subcentral as in the genus Tonicia Gray, 1847) (Kaas et al. 2006: 294). We did not observe the presence of ocelli in the postmucronal area. The characters of this single tail valve are so distinctive that they warrant description as a new species. The peculiar granulose sculpture of this species is different from that of other Lucilina species known from the Red Sea (including those described herein), and Indian Ocean (Kaas et al. 2006). Distribution. Late Pleistocene: Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study).

Genus Acanthopleura Guilding, 1829 Type species. Chiton spinosus Brugui��re, 1792, by subsequent designation (Gray 1847). Distribution. The western part of the Indian Ocean, the East Indies to the central part of the Pacific Ocean, the western coast of South America, and the Caribbean area. The genus is known from the Pleistocene to the presentday., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on page 428, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Guilding, L. (1829) Observations on the Chitonidae. The Zoological Journal, 5 (17), 25 - 35.","Gray, J. E. (1847) A list of the genera of Recent Mollusca, their synonyms and types. Proceedings of the Zoological Society of London, 15, 129 - 206. https: // doi. org / 10.1111 / j. 1469 - 7998.1847. tb 00164. x"]}

Lucilina aegyptiaca n. sp. (Fig. 14) Type material. Holotype: MZB 50546, intermediate valve, width 4 mm (Figs 14 A–D). Paratypes: RGM.1356859, intermediate valve, width 3mm; MZB 50547, tail valve, width 3 mm (Figs 14 E–H). Type locality. Hurghada, Egypt (St. 13). Other material examined. Egypt, Hurghada (St. 13): 5 valves (4 intermediate and 1 tail) (BD 212). Recent material examined. Zabargad Island (13/30): 2 intermediate valves (Figs 14 I–L) (MZB 50548). Maximum width. - / 4.4 / 3 mm. Type stage. Late Pleistocene, last interglacial MIS5e. Etymology. The name refers to the country (Egypt) providing all the material belonging to this new species known to date. Diagnosis. Intermediate valve rectangular, moderately elevated, subcarinated in anterior profile, posterior margin almost straight at both sides of prominent apex, almost triangular; tail valve semicircular, mucro small, not very prominent, in subcentral position, antemucronal slope almost straight, postmucronal slope convex. Tegmentum sculptured with irregular radial striae of roundish granules on lateral areas of intermediate valves and postmucronal area of tail valve; central area of intermediate valves and postmucronal area of tail valve sculptured with irregular longitudinal striae of ellipsoidal granules, with reduced interspace. Articulamentum white, apophyses rounded, trapezoidal in tail valve, jugal sinus wide, slit formula: -/1/8, teeth of tail valve slightly forwardly directed. Description. Intermediate valve rectangular, L/W ratio = 0.60, anterior margin convex, moderately elevated (H/W = 0.42), subcarinated in anterior profile, side margins rounded, posterior margin almost straight at both sides of prominent apex, almost triangular, forming angle of ca 130°, pleural areas with ca 30–35 longitudinal, irregular striae of granules (with reduced interspace, larger towards lateral sides), present, but less evident on jugal area, ellipsoidal granules, drop shaped, widely spaced, 60 µm wide and up to 100 µm long, in some cases tending to be more roundish towards lateral sides (Fig. 14A), lateral areas not raised, with irregular radial striae of more roundish granules, ocelli scarcely visible in anterior third. Tail valve semicircular, length ca half width (L/W = 0.52), anterior margin slightly sinuose, mucro small, not very evident, in subcentral position, antemucronal slope almost straight, postmucronal slope convex, antemucronal area sculptured like pleural area of intermediate valves, postmucronal area with irregular sculpture like lateral areas of intermediate valves, ocelli randomly dispersed in postmucronal area. Articulamentum white, apophyses rounded, trapezoidal in tail valve, jugal sinus wide, slit formula: -/1/8, slit rays not indicated, teeth of tail valve slightly forwardly directed, all teeth finely grooved on upper side, denticulated on outer edge, eaves narrow, solid. Remarks. Only a few poorly preserved and often incomplete intermediate valves and two tail valves from a single locality are present in the studied fossil material. The exit holes of the canals of the aesthetes embedded in the tegmentum are clearly visible in the pleural areas (Fig. 14B). Lucilina aegyptiaca n. sp. is similar to L. confusa n. sp. and L. colantonii n. sp., from which it differs in numerous characters, summarised in Tab. 2. Numerous intermediate valves of Lucilina aegyptiaca n. sp. are present in the extant material from the Red Sea expeditions (currently under study, unpublished), mixed in samples initially labeled as L. sueziensis and L. perligera. One of these valves is illustrated for comparison (Fig. 14 I–L). No differences were observed between the extant and fossil valves. The extant valves are well preserved, and we can give some additional information, e.g. the irregular radial striae of lateral areas (Fig. 14K), with granules oval/roundish, length up to 100 µm, ocelli with a diameter of 44–48 µm. We can therefore confirm the presence of this species in the present-day chiton fauna of the Red Sea. Distribution. Late Pleistocene: Egypt (Hurghada: this study). Present-day: Red Sea, Zabargad island (this study).

Lucilina confusa n. sp. (Fig. 11, 12) Type material. The type material is reported in Tab. 2. Other material. Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd): St. 8: 12 valves (2 head and 10 intermediate) (MZB 60258); St. 9: 20 valves (3 head and 17 intermediate) (MZB 60259). Egypt, Hurghada: St. 13: 33 valves (2 head, 24 intermediate and 7 tail), Figs 11 M–N (BD 205; MZB 50543); St. 14: 33 valves (5 head, 21 intermediate and 7 tail) (BD 206; RGM.1356858); St. 14bis: 18 valves (1 head, 11 intermediate and 6 tail) (BD 207); St. 15: 3 valves (1 head, 1 intermediate and 1 tail) (BD 208); St. 16: 8 valves (2 head, 3 intermediate and 3 tail (BD 209). Recent material examined. Zabargad island (13/30): 42 valves (5 head, 28 intermediate and 9 tail) (Figs 12 A- I) (MZB 50544). Sudan, Sha’ab Rum Reef (P078): 14 valves (2 head, 10 intermediate and 2 tail) (BD 210). Egypt, Gulf of Aqaba (Blue Hole) (P447A): 3 intermediate valves (BD 211). Maximum width: 4.4 / 7.5 / 7.2 mm. Type locality. Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study): St. 9. Type stage. Late Pleistocene, last interglacial (MIS5e). Etymology. The name indicates the fact that a rather common species in this region has been for long confused with morphologically close taxa. Diagnosis. Head valve semicircular; intermediate valve rectangular, moderately elevated, anterior profile subcarinated, posterior margin slightly concave at both sides of prominent apex, lateral areas not raised; tail valve semicircular, mucro small, raised, in posterior position, antemucronal slope almost straight, postmucronal slope steep, straight to weakly convex. Tegmentum sculptured with irregular radial striae of roundish granules on head valve, lateral areas of intermediate valves and postmucronal area of tail valve; central area of intermediate valves and postmucronal area of tail valve sculptured with irregular and well-separated longitudinal striae of rounded to oval granules.Articulamentum white, apophyses well developed, rounded, jugal sinus wide, slit formula 8/1/9, teeth relatively long, finely grooved on upper side, denticulated on outer edge. Description. Head valve (based on Paratype 1, Fig. 11F) semicircular, front slope slightly convex, posterior margin widely V-shaped, tegmentum sculptured with ca 34 irregularly radial striae of roundish, elevated granules (diameter ca 60–75 µm), up to 10–12 granules per stria; striae do not start from apex, but from small, smooth circular area around apex, ocelli minute (diameter ca 40 µm), scarcely visible, aligned in interstices of radial striae of granules. Intermediate valve (based on Paratype 2, Fig. 11J) rectangular, L/W = 0.38, anterior margin sinuose, slightly concave in wide central part, convex at pleurae, moderately elevated (H/W = 0.36), anterior profile subcarinated, side margins rounded, posterior margin slightly concave at both sides of prominent apex, lateral areas not raised, sculptured like head valve with 7–8 irregular radial striae of granules, ocelli numerous in anterior third of valve, pleural areas with similar granules arranged in ca 20–22 longitudinal, irregular and well-separated striae on each side, slightly oblique near jugum and in opposite direction towards side margins, granules more irregular, rounded to oval, diameter up to 100 µm, jugal area smooth, triangular, irregularly defined. Tail valve (based on Holotype, Fig. 11A) semicircular, length ca half width (L/W = 0.51), front margin almost straight, mucro small, raised, in posterior position, antemucronal slope almost straight, postmucronal slope steep, straight to weakly convex, antemucronal area sculptured with ca 16 longitudinal striae of roundish-oval, more elevated granules on each side, with granule diameter up to 70 µm, jugal area smooth, irregularly defined, postmucronal area with sculpture like head valve with ca 40 radial striae of granules, ocelli randomly dispersed in postmucronal area. Articulamentum white, apophyses well developed, rounded, jugal sinus wide, slit formula 8/1/9, slit rays faintly visible in head and intermediate valves, teeth relatively long, those of tail valve slightly forwardly directed, all teeth finely grooved on upper side, denticulated on outer edge, eaves narrow, solid. Variability. The species show a great variability in the sculpture of the valves as well as other characters. Head valve: the radial striae of roundish, elevated granules, can be more irregularly defined, large and widely spaced as in the figured valve from Egypt, Hurghada (Fig. 11M, width 3.3 mm, ca 25 radial striae, diameter up to 90–100 µm, ca 6–7 granules for each radial stria). The number of more or less irregular radial striae of granules ranges between 25 and 35, and the number of slits in the articulamentum ranges between six and eight. Intermediate valves: the number and the orientation of longitudinal striae of granules in the pleural areas is variable, as can be seen in the figured valve from Egypt, Hurghada (Fig. 11N, width 5 mm, ca 16 longitudinal striae on each side, striae more regular and parallel). Also the radial striae of granules in lateral areas are generally irregularly defined, in some valves are more numerous and well defined (as in Fig. 11N). L/W = 0.36–0.41; H/W = 0.33–0.37. The jugal area is usually triangular and smooth, only in very few valves the striae of granules cover partially the jugal area, leaving a very narrow, wedge shaped, smooth band. The ocelli are scarcely visible, not black, and can radially cover up to half of the lateral area. Tail valve: the sculpture shows the same variability as in intermediate valves, also for these valves the striae of granules can partially cover the jugal area (Fig. 11O).The number of slits ranges between 9 and 12. Remarks. Several species of Lucilina are known from the Indian Ocean (Kaas et al. 2006), but only two from the Red Sea, L. sueziensis (Reeve, 1847) and L. perligera Thiele, 1909 (see above) (Anseeuw & Terryn 2004). Lucilina perligera is similar to Lucilina confusa n. sp., from which it differs mainly by the tegmentum sculptured with large, elevated, roundish, clearly separated, quincuncially arranged, granules in the head valve, lateral areas of intermediate valves, and postmucronal area of the tail valve, while in pleural and antemucronal areas the granules are vaguely arranged in curved, forwardly converging rows, also extending over the jugum. The granules are larger, and wider spaced than those of L. confusa n. sp. Two other Lucilina species are present in the studied material and have a similar sculpture with longitudinal and radial striae of granules: Lucilina aegyptiaca n. sp. and Lucilina colantonii n. sp. (see below). The main characters of the intermediate valves of these species and of L. sueziensis (based on the description of Kaas et al. 2006 and on personal observations) are presented in Tab. 3. Numerous valves of Lucilina confusa n. sp. are present in the extant material from the Red Sea expeditions (currently under study, unpublished), mixed in samples initially labeled as L. sueziensis and L. perligera. Some of these valves are illustrated for comparison (Figs 12 A–I). No significant differences were found between the fossil and extant valves described in this study. The figured head valve (Figs 12 A–C) has ca 35 irregular radial striae of granules, with striae of ocelli in the interstices (diameter ca 40 µm), eight slits, and falls within the range of variability indicated above. Similarly, the intermediate valve (Figs 12 D–F) and the figured tail valve (Figs 12 G–I) fall within the range of variability indicated above. The longitudinal striae of granules in intermediate valves partially extends over the jugal area (Fig. 12D), only a small part near the anterior margin is smooth. Distribution. Late Pleistocene: Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study); Egypt (Hurghada: this study). Present-day: Red Sea: Zabargad island; Sudan (Shab Runi Reef); Egypt, Gulf of Aqaba (Blue Hole).

Genus Choneplax Dall, 1882 Type species. Chiton strigatus Sowerby, 1840 (= Chitonellus latus Guilding, 1829), by original designation. Remarks. The genus Choneplax Dall, 1882 includes four Recent species (Sirenko 2003): C. lata (Guilding, 1829) from the Caribbean, C. hastata (Sowerby, 1840), habitat unknown (fide Sirenko 2003), C. indica from the W. Indian Ocean, and C. littlerorum Sirenko, 2003 from American Samoa. This is the first fossil record for the genus. Distribution. Indian and Pacific (American Samoa) Oceans, and West Atlantic, Pleistocene to present-day., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on page 435, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Dall, W. H. (1882) On the genera of chitons. Proceedings of the United States National Museum, 4, 279 - 291. https: // doi. org / 10.5479 / si. 00963801.4 - 228.279","Guilding, L. (1829) Observations on the Chitonidae. The Zoological Journal, 5 (17), 25 - 35.","Sirenko, B. I. (2003) First Pacific species of the genus Choneplax (Mollusca: Polyplacophora). Ruthenica, 13, 33 - 39."]}

Lucilina aegyptiaca n. sp. (Fig. 14) Type material. Holotype: MZB 50546, intermediate valve, width 4 mm (Figs 14 A���D). Paratypes: RGM.1356859, intermediate valve, width 3mm; MZB 50547, tail valve, width 3 mm (Figs 14 E���H). Type locality. Hurghada, Egypt (St. 13). Other material examined. Egypt, Hurghada (St. 13): 5 valves (4 intermediate and 1 tail) (BD 212). Recent material examined. Zabargad Island (13/30): 2 intermediate valves (Figs 14 I���L) (MZB 50548). Maximum width. - / 4.4 / 3 mm. Type stage. Late Pleistocene, last interglacial MIS5e. Etymology. The name refers to the country (Egypt) providing all the material belonging to this new species known to date. Diagnosis. Intermediate valve rectangular, moderately elevated, subcarinated in anterior profile, posterior margin almost straight at both sides of prominent apex, almost triangular; tail valve semicircular, mucro small, not very prominent, in subcentral position, antemucronal slope almost straight, postmucronal slope convex. Tegmentum sculptured with irregular radial striae of roundish granules on lateral areas of intermediate valves and postmucronal area of tail valve; central area of intermediate valves and postmucronal area of tail valve sculptured with irregular longitudinal striae of ellipsoidal granules, with reduced interspace. Articulamentum white, apophyses rounded, trapezoidal in tail valve, jugal sinus wide, slit formula: -/1/8, teeth of tail valve slightly forwardly directed. Description. Intermediate valve rectangular, L/W ratio = 0.60, anterior margin convex, moderately elevated (H/W = 0.42), subcarinated in anterior profile, side margins rounded, posterior margin almost straight at both sides of prominent apex, almost triangular, forming angle of ca 130��, pleural areas with ca 30���35 longitudinal, irregular striae of granules (with reduced interspace, larger towards lateral sides), present, but less evident on jugal area, ellipsoidal granules, drop shaped, widely spaced, 60 ��m wide and up to 100 ��m long, in some cases tending to be more roundish towards lateral sides (Fig. 14A), lateral areas not raised, with irregular radial striae of more roundish granules, ocelli scarcely visible in anterior third. Tail valve semicircular, length ca half width (L/W = 0.52), anterior margin slightly sinuose, mucro small, not very evident, in subcentral position, antemucronal slope almost straight, postmucronal slope convex, antemucronal area sculptured like pleural area of intermediate valves, postmucronal area with irregular sculpture like lateral areas of intermediate valves, ocelli randomly dispersed in postmucronal area. Articulamentum white, apophyses rounded, trapezoidal in tail valve, jugal sinus wide, slit formula: -/1/8, slit rays not indicated, teeth of tail valve slightly forwardly directed, all teeth finely grooved on upper side, denticulated on outer edge, eaves narrow, solid. Remarks. Only a few poorly preserved and often incomplete intermediate valves and two tail valves from a single locality are present in the studied fossil material. The exit holes of the canals of the aesthetes embedded in the tegmentum are clearly visible in the pleural areas (Fig. 14B). Lucilina aegyptiaca n. sp. is similar to L. confusa n. sp. and L. colantonii n. sp., from which it differs in numerous characters, summarised in Tab. 2. Numerous intermediate valves of Lucilina aegyptiaca n. sp. are present in the extant material from the Red Sea expeditions (currently under study, unpublished), mixed in samples initially labeled as L. sueziensis and L. perligera. One of these valves is illustrated for comparison (Fig. 14 I���L). No differences were observed between the extant and fossil valves. The extant valves are well preserved, and we can give some additional information, e.g. the irregular radial striae of lateral areas (Fig. 14K), with granules oval/roundish, length up to 100 ��m, ocelli with a diameter of 44���48 ��m. We can therefore confirm the presence of this species in the present-day chiton fauna of the Red Sea. Distribution. Late Pleistocene: Egypt (Hurghada: this study). Present-day: Red Sea, Zabargad island (this study)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on pages 424-425, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654

Callochiton vanninii Ferreira, 1983 (Fig. 5) Callochiton vanninii Ferreira 1983, p. 259, figs 11���19; Strack 1993, p. 6, pl. 2, fig. 8; Bosch et al. 1995, p. 189; Kaas & Van Belle 1998, p. 194; Dekker & Orlin 2000, p. 7; Slieker 2000, p. 46, pl. 11, fig. 5; Schwabe 2003, p. 23; Anseeuw & Terryn 2004, p. 6, fig. 37; Dell���Angelo et al. 2004, p. 51, pl. 2, figs 9���14; Kaas et al. 2006, p. 22, fig. 3, map 20; Dinapoli & Janssen 2009, p. 5, pl. 2a��� d; Dell���Angelo et al. 2010a, p. 11; Mohammadian 2011, p. 211; Dell���Angelo et al. 2012, p. 156; Blatterer 2019, p. 49, pl. 1, fig. 3 a-m. Non Callochiton vanninii; Kaas & Van Belle 1985b, p. 44, fig. 18; Kaas 1985, p. 327; Kaas 1986, p. 10, fig. 6 (= Callochiton levatus Kaas, Van Belle & Strack, 2006). Type material. Holotype: MZUF 4098; Paratype: CAS 031758. Type locality. Gesira, Somalia. Material examined. Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study): St. 7: 1 tail valve (MZB 50590); St. 9: 1 intermediate valve (MZB 50591). Egypt, Hurghada: St. 12: 11 valves (1 head, 8 intermediate and 2 tail) (BD 185); St. 13: 96 valves (12 head, 70 intermediate and 14 tail), Figs 5 A���L (BD 186; MZB 50528; RGM.1356851). Egypt, Hamata: St. 18: 1 intermediate valve (MZB 60271). Maximum width: 2.5 / 3.7 / 3.5 mm. Description. Head valve semicircular, posterior margin widely V-shaped, front slope slightly convex. Intermediate valves rectangular, front margin sinuous, weakly concave in wide central part, convex and somewhat slanting at pleurae, moderately elevated (H/W = 0.30���0.48), anterior profile rounded to subcarinated, side margins rounded, posterior margin slightly concave at both sides of bluntly protruding apex, lateral areas raised, clearly defined by diagonal depression. Tail valve semicircular, L/W = 0.60���0.65, front margin straight in jugal part, mucro in anterior position, little elevated, forwardly directed, antemucronal and postmucronal slopes almost straight. Tegmental surface minutely granulose and microscopically striated, longitudinally on central and antemucronal areas, radially on head valve, lateral and postmucronal areas, shell eyes not visible. Articulamentum with apophyses very wide, short, slightly rounded, connected across narrow, shallow sinus by short jugal plate, insertion plates well developed, slit formula 15���20/2/17���21, slits deep, neatly cut, slit rays clearly visible, teeth sharp, somewhat roughened on upper side and outer edge, eaves narrow, porous. Remarks. A detailed description of this species was provided by Kaas et al. (2006). Callochiton vanninii Ferreira, 1983 is very similar to Callochiton levatus Kaas, Van Belle & Strack, 2006 from Madagascar, R��union, Mauritius and Chagos Archipelago, from which it can be distinguished mainly by the different shape of the tail valve (broadly oval with an extended, but not laterally protruding, articulamentum in C. levatus, semicircular with wide, but short, apophyses in C. vanninii), the different slit formula (12���14/1���2/ 10���12 in C. levatus vs 16/2���3/ 16 in C. vanninii) (Strack 1993; Kaas et al. 2006) and by differences in their radular teeth (Schwabe 2003). Callochiton vanninii is present at only three sites sampled, but only at one (St. 13) is it represented by a large number of valves. The valves are not well preserved, often eroded, and usually incomplete, especially the intermediate ones. The intermediate valves show a variability in the dorsal elevation, the H/W ratio ranges from 0.30 to 0.48, with the anterior profile subcarinate in the valves with lower values of H/W ratio (Figs 5 D���F, H/W = 0.30), tending to be rounded in the apex with the growth of this ratio (Fig. 5G, H /W = 0.48). Also the tail valves show a certain variability in shape (L/W ratio). The number of slits of head and tail valves is higher than that reported for this species (Kaas et al. 2006: 15���16 for both valves), 20 and 21, respectively. We illustrate two tail valves, with 18 slits (Figs 5 H���I, L/W = 0.60) and 21 slits (Figs 5 J���L, L/W = 0.65), respectively. Despite the differences highlighted in the number of slits, we provisionally attribute the studied material to Callochiton vanninii, pending better preserved material to further characterise the fossil species. This is the first report of this species as a fossil. Distribution. Late Pleistocene: Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd); Egypt (Hurghada, Hamata: this study). Present-day: Indian Ocean: Red Sea, Somalia, Madagascar, Arabian Gulf (Bahrein), Socotra Island (Dinapoli & Janssen 2009; Blatterer 2019)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on pages 410-411, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Ferreira, A. J. (1983) Researches on the coast of Somalia. The chiton fauna (Mollusca Polyplacophora). Monitore Zoologico Italiano, 9, 249 - 297. https: // doi. org / 10.1080 / 00269786.1983.11758574","Strack, H. L. (1993) The Polyplacophora of the Red Sea. Journal of the Malacological Society of Australia, 14, 1 - 40. https: // doi. org / 10.1080 / 00852988.1993.11923901","Bosch, D. T., Dance, S. P., Moolenbeek, R. G. & Oliver, P. G. (1995) Seashells of Eastern Arabia. Motivate Publishing, Dubai, 290 pp.","Kaas, P. & Van Belle, R. A. (1998) Catalogue of living chitons (Mollusca, Polyplacophora). Second, revised edition. Backuys Publishers, Leiden, 204 pp.","Dekker, H. & Orlin, Z. (2000) Check-list of Red Sea Mollusca. Spirula, 47 (Supplement), 1 - 46.","Slieker, F. J. A. (2000) Chitons of the world. An illustrated synopsis of recent Polyplacophora. L'Informatore Piceno Ed., Ancona, 154 pp.","Schwabe, E. (2003) Taxonomic notes on chitons. 3. Notes on the genus Callochiton Gray, 1847 (Mollusca: Polyplacophora: Callochitonidae) from the Indian Ocean. Malakologische Abhandlungen, 21, 19 - 27.","Anseeuw, B. & Terryn, Y. (2004) Intertidal chitons (Mollusca: Polyplacophora) from the coast of Jordan, Red Sea, with the description of a new species of Parachiton Thiele, 1909. Bollettino Malacologico, Supplement 5, 1 - 24.","Dell'Angelo, B., Bonfitto, A., Sabelli, B. & Taviani, M. (2004) Chitons (Mollusca, Polyplacophora) from bioclastic sands of the Ifaty-Tulear back reefs (Madagascar, Western Indian Ocean). Bollettino Malacologico, Supplment 5, 45 - 62.","Kaas, P., Van Belle, R. A. & Strack, H. L. (2006) Monograph of Living Chitons (Mollusca: Polyplacophora). Volume 6. Suborder Ischnochitonina (concluded): Schizochitonidae; Chitonidae. Additions to Volumes 1 - 5. E. J. Brill, Leiden-Boston, 463 pp.","Dinapoli, A. & Janssen, R. (2009) Polyplacophora (Mollusca) of the Socotra Arcipelago - Systematics and Biogeography. Fauna of Arabia, 24, 1 - 46.","Dell'Angelo, B., Gori, S., Baschieri, L. & Bonfitto, A. (2010 a) Chitons (Mollusca, Polyplacophora) from the Maldive islands. Zootaxa, 2673 (1), 1 - 38. https: // doi. org / 10.11646 / zootaxa. 2673.1.1","Mohammadian, H. (2011) The molluscs in Iran. Shabpareh Publishing Company, Tehran, 229 pp. [in Arabic script]","Dell'Angelo, B., Garilli, V., Germana, A., Reitano, A., Sosso, M. & Bonfitto, A. (2012) Notes on fossil chitons. 4. Polyplacophora from the Pliocene of Altavilla (NW Sicily). Bollettino Malacologico, 48, 51 - 68.","Blatterer, H. (2019) Mollusca of the Dahab region. Oberosterreichisches Landesmuseum, Linz, Austria, 480 pp.","Kaas, P. & Van Belle, R. A. (1985 b) Monograph of Living Chitons (Mollusca: Polyplacophora). Vol. 2. Suborder Ischnochi- tonina, Ischnochitonidae: Schizoplacinae, Callochitoninae & Lepidochitoninae. E. J. Brill, W. Backhuys, Leiden, 198 pp.","Kaas, P. (1986) Revision of the chitons (Mollusca: Polyplacophora) from the coral-reefs of Tulear, SW Madagascar, and of the Mascarene Islands. Mesogee, 46, 9 - 23."]}

Lucilina colantonii n. sp. (Fig. 15) Type material. Holotype: MZB 50549, intermediate valve, width 2.7 mm (Figs 15 A���C). Paratype: RGM.1356860, intermediate valve, width 3.9 mm (Figs 15 D���F). Type locality. Hurghada, Egypt (St. 16). Other material examined. Egypt, Hurghada: St. 13: 2 intermediate valves (BD 213); St. 14: 2 intermediate valves (BD 214); St. 16: 1 intermediate valve (BD 215). Recent material examined. Sudan, Shab Runi Reef (P078): 2 intermediate valves, Figs 15 J���L (BD 216, MZB 50551); Sudan, Sanganeb Reef (D08): 1 intermediate valve (MZB 60260); Egypt, Gulf of Aqaba (P447): 4 intermediate valves, Figg 15 G���I (BD 217; MZB 50550); Egypt, Gulf of Aqaba, Blue Hole (P447A): 1 intermediate valve (BD 218). Maximum width of the intermediate valves: 5.5 mm. Type stage. Late Pleistocene, last interglacial MIS5e. Etymology. This species honours the marine geologist Paolo Colantoni (1934���2015) who first introduced M.T. to the study of recent and fossil molluscs of the Gulf of Aqaba. Diagnosis. Intermediate valve rectangular, moderately elevated, semicarinate in anterior profile, posterior margin almost straight at both sides of prominent apex, almost triangular, pleural areas with longitudinal regular striae of small, roundish granules, jugal area large, smooth, lateral areas not raised, with irregular radial striae of similar granules. Articulamentum white, apophyses small, triangular, jugal sinus wide, one slit, teeth finely grooved on upper side. Description. Intermediate valve rectangular, L/W ratio = 0.53���0.63, anterior margin convex, moderately elevated (H/W = 0.36���0.41), semicarinate in anterior profile, side margins slightly rounded, posterior margin almost straight at both sides of prominent apex, almost triangular, forming an angle of ca 120���130��, pleural areas with longitudinal and enough regular striae of small, roundish granules, ca 10���12 on each side, with reduced spaces between the striae of granules, jugal area large, smooth, lateral areas not raised, with 6���7 irregular radial striae of similar granules, ocelli scarcely visible in anterior third. Granules of longitudinal striae entirely covered by aesthetes of the same dimensions, not regularly arranged. Articulamentum white, apophyses small, triangular, jugal sinus wide, one slit, slit rays not indicated, teeth finely grooved on upper side. Remarks. Only poorly preserved and often incomplete intermediate valves are present in the studied material. The species is similar to Lucilina aegyptiaca n. sp., from which it differs in several characters (Tab. 3). The distribution of the aesthetes on the granules of the longitudinal striae is unusual, they are of the same di- mensions and arranged without a particular order, in contrast to the norm (generally with one or more central macroaesthetes and several microaesthetes arranged along the edge of the granule). Numerous valves of Lucilina colantonii n.sp. were identified in extant Red Sea material still unpublished, mixed in samples initially labeled L. sueziensis and L. perligera. Two such valves are illustrated for comparison (Fig. 15 G���L). No significant differences appear between extant and fossil valves. The extant valves are well preserved and show additional characters not preserved in the fossil state, namely the presence of longitudinal striae of small roundish granules with a diameter up to 60 ��m, and ocelli with a diameter of 33���37 ��m. Distribution. Late Pleistocene: Egypt (Hurghada: this study). Present-day (this study): Sudan, Sha���ab Rum Reef, Sanganeb Reef; Egypt, Gulf of Aqaba (Blue Hole)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on pages 425-427, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654

Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio, Taviani, Marco (2020): Late Pleistocene Red Sea Mollusca: 1. Polyplacophora. Zootaxa 4772 (3): 401-449, DOI: https://doi.org/10.11646/zootaxa.4772.3.1

Rhyssoplax affinis (Issel, 1869) (Fig. 7) Chiton affinis Issel 1869, p. 234; Sykes 1907, p. 34; Pallary 1926, p. 30, pl. 4, figs 8���9 (ex Savigny 1817: pl. 3, figs 8���9); Moazzo 1939, p. 217; Yaron 1973, p. 15; Bouchet & Danrigal 1982, p. 11, fig. 51; Dekker & Orlin 2000, p. 7; Abubakr 2004, p. 73; Dekker & Gemert 2008, p. 124. Chiton (Clathropleura) affinis; Thiele 1909, p. 91, pl. 9, figs 41���44. Chiton olivaceus Spengler var. affinis; Leloup, 1952, p. 27, text-fig. 11, pl. 4, fig. 4; Leloup 1960, p. 36; Vine 1986, p. 125, unnumbered fig. p. 125. Rhyssoplax affinis; Ferreira 1983, p. 268, figs 22, 24; Blatterer 2019, p. 52, pl. 3, fig. 7 a���s. Chiton (Rhyssoplax) affinis; Kaas & Van Belle 1988, p. 122, figs 34���40; Van Belle & Wranik 1991, p. 372, fig. 18; Van Belle 1994, p. 6; Bosch et a l. 1995, p. 190, fig. sp. 884; Kaas 1996, p. 371; Schwabe 1997, p. 26, unnumbered figs at p. 27; Kaas & Van Belle 1998, p. 14; Anseeuw & Terryn 2004, p. 11, figs 5, 42���43; Kaas et al. 2006, p. 165, fig. 61, map 30; Di Napoli & Janssen 2009, p. 15, pl. 8a���d; Schwabe 2010, figs 1A, 2A, 5A���B; Mohammadian 2011, p. 211. Type material. Lectotype MNHN in Savigny Collection, designated by Ferreira (1983: 268), as illustrated in Bouchet & Danrigal (1982: fig. 51). Type locality. Gulf of Suez. Material examined. Jordan, Aqaba (Yamanie) (St. 1): 2 intermediate valves (MZB 50592). Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd): St. 2: 1 intermediate valve (MZB 50593); St. 7: 1 intermediate valve (MZB 50594); St. 8: 10 intermediate valves (MZB 50595); St. 9: 6 valves (1 head, 4 intermediate and 1 tail) (MZB 50596). Egypt (Hurghada): St. 13: 48 valves (3 head, 36 intermediate and 9 tail), Figs 7 G���I (BD 187; MZB 50531); St. 14: 106 valves (10 head, 90 intermediate and 6 tail), Figs 7 A���F (BD 188; MZB 50530); RGM.1356852); St. 14bis: 4 valves (3 intermediate and 1 tail) (BD 189); St. 15: 3 valves (2 intermediate and 1 tail) (BD 190); St. 16: 59 valves (12 head, 36 intermediate and 11 tail) (BD 191). Maximum width: 4 / 7.1 / 4 mm. Description. Head valve semi-circular, posterior margin widely V-shaped, front slope slightly convex, tegmentum sculptured with 13���14 strong radial ribs, some bifurcating, interstices pitted. Intermediate valve rectangular, L/W = 0.34���0.42, front margin sinuous, moderately to highly elevated (H/W = 0.42���0.47), anterior profile carinated, side margins short, weakly bilobed, posterior margin straight at both sides of well defined apex, lateral areas clearly defined, sculptured like head valve, 2 radial ribs separated by pitted interstices, pleural areas with ca 10 longitudinal, slightly forwardly converging grooves, innermost not reaching anterior margin of valve, interspaces somewhat broader, smooth, jugal area narrow, smooth. Tail valve semi-circular, length more than half the width (L/W = 0.58���0.60), front margin slightly convex, posterior margin lobate, mucro well defined, subcentral, prominent, antemucronal slope almost straight or slightly convex, postmucronal slope slightly convex, antemucronal area sculptured like central area of intermediate valve, postmucronal area with sculpture like head valve. Articulamentum with apophyses wide, short, connected across the shallow sinus by short, denticulated jugal plate, insertion plates short, slit formula 8/1/10���13, teeth inequidistant, irregular, finely striated on the upper side, slit rays not indicated. Remarks. Issel��s original description (1869) has subsequently been revised by several authors (Leloup 1952; Ferreira 1983; Kaas et al. 2006). Rhyssoplax affinis has been confused with the Mediterranean R. olivaceus (Spengler, 1797) by authors following Cooke (1885). The controversy, summarized by Leloup (1952), was resolved by Yaron (1973), who demonstrated consistent morphological differences between the two species. This is the first report of this species as a fossil. Distribution. Late Pleistocene: Jordan, Aqaba (Yamanie); Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd); Egypt (Hurghada: this study). Present-day: Indian Ocean: Red Sea, Gulf of Suez, Yemen, Socotra Island, Gulf of Oman, the Arabian Gulf, Seychelles and Somalia (Kaas et al. 2006; Di Napoli & Janssen 2009; Blatterer 2019)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on pages 412-414, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Issel, A. (1869) Malacologia del Mar Rosso. Ricerche zoologiche e paleontologiche. Parte terza. Catalogo delle conchiglie fossili raccolte sulle spiagge emerse del Mar Rosso. Biblioteca Malacologica, Pisa, 61 pp. [pp. 243 - 303]","Sykes, E. R. (1907) Reports on the marine biology of the Sudanese Red Sea. 5. On the Polyplacophora or chitons. Journal of the Linnean Society of London, 31, 31 - 34. https: // doi. org / 10.1111 / j. 1096 - 3642.1907. tb 00450. x","Pallary, P. (1926) Explication des planches de J. C. Savigny. Memoires de l'Institut d'Egypte, 11, i-viii + 1 - 139, pls. 1 - 18.","Savigny, J. C. (1817) Description de l'Egypte, ou recueil des observations et des recherches qui ont ete faites en Egypte pendant l'Expedition de l'armee francaise, publiee par ordre du gouvernement. Histoire naturelle. Planches. Vol. II. Imprimerie royale, Paris, IV + 69 + 36 + 24 + 16 + 20 + 44 + 79 + 51 + 26 + 4 + 18 + 18 + 98 + 22 + 24 + 12 + 95 + 63 + 12 + 2 pp.","Moazzo, P. G. (1939) Mollusques testaces marins du Canal de Suez. Memoires de l'Institut d'Egypte, 38, 1 - 287.","Yaron, I. (1973) A note on the taxonomic status of Chiton affinis Issel. Argamon, 4, 15 - 17.","Bouchet, P. & Danrigal, F. (1982) Napoleon's Egyptian Campaign (1798 - 1801) and the Savigny Collection of Shells. The Nautilus, 96, 9 - 24.","Dekker, H. & Orlin, Z. (2000) Check-list of Red Sea Mollusca. Spirula, 47 (Supplement), 1 - 46.","Abubakr, M. M. (2004) The Republic of Yemen Marine Biotic Ecosystem (Resources-Habitats and Species). Ministry of Water and Environment, Environment Protection Authority, Aden, 128 pp.","Dekker, H. & Gemert, L. J. van (2008) A new list with corrections to the shells pictured in \" Red Sea Shells \" (1984) by Doreen Sharabati. De Kreukel, 44, 123 - 136.","Thiele, J. (1909) Revision des Systems der Chitonen. Zoologica, 22, 1 - 132, pls. 1 - 10. https: // doi. org / 10.5962 / bhl. title. 11245","Leloup, E. (1952) Polyplacophores de l'Ocean Indien et des cotes de l'Indochine francaise. Institut Royale des Sciences Naturelles de Belgique, Memoires, Series 2, 7, 1 - 69, 6 pls.","Leloup, E. (1960) Amphineures du golfe d'Aqaba et de la Peninsule Sinai. Sea Fisheries Research Station, Haifa, Bulletin, 29, 29 - 55, pl. 1.","Vine, P. (1986) Red Sea Invertebrates. IMMEL Publishing, London, 224 pp.","Ferreira, A. J. (1983) Researches on the coast of Somalia. The chiton fauna (Mollusca Polyplacophora). Monitore Zoologico Italiano, 9, 249 - 297. https: // doi. org / 10.1080 / 00269786.1983.11758574","Blatterer, H. (2019) Mollusca of the Dahab region. Oberosterreichisches Landesmuseum, Linz, Austria, 480 pp.","Kaas, P. & Van Belle, R. A. (1988) Chitons (Mollusca: Polyplacophora) from the coasts of Oman and the Arabian Gulf. American Malacological Bulletin, 6, 115 - 130.","Van Belle, R. A. & Wranik, W. (1991) Chitons (Mollusca: Polyplacophora) from the Coasts of Yemen and Socotra Island. Fauna of Saudi Arabia, 12, 366 - 381.","Van Belle, R. A. (1994) On the chiton fauna of Bahrain, Arabian Gulf. Gloria Maris, 33, 1 - 6.","Kaas, P. (1996) Chitons (Mollusca: Polyplacophora) from the Seychelles with description of a new species. Zoologische Mededelingen, 70, 367 - 375, figs. 1 - 11.","Schwabe, E. (1997) Beitrag zur Kenntnis einiger Kaferschnecken (Polyplacophora) des Roten Meeres. Club Conchylia Informationen, 29, 25 - 30.","Kaas, P. & Van Belle, R. A. (1998) Catalogue of living chitons (Mollusca, Polyplacophora). Second, revised edition. Backuys Publishers, Leiden, 204 pp.","Anseeuw, B. & Terryn, Y. (2004) Intertidal chitons (Mollusca: Polyplacophora) from the coast of Jordan, Red Sea, with the description of a new species of Parachiton Thiele, 1909. Bollettino Malacologico, Supplement 5, 1 - 24.","Kaas, P., Van Belle, R. A. & Strack, H. L. (2006) Monograph of Living Chitons (Mollusca: Polyplacophora). Volume 6. Suborder Ischnochitonina (concluded): Schizochitonidae; Chitonidae. Additions to Volumes 1 - 5. E. J. Brill, Leiden-Boston, 463 pp.","Schwabe, E. (2010) Illustrated summary of chiton terminology. Spixiana, 33, 171 - 194.","Mohammadian, H. (2011) The molluscs in Iran. Shabpareh Publishing Company, Tehran, 229 pp. [in Arabic script]","Spengler, L. (1797) Udforlig beskrivelse over det mangeskallede konkylie-slaegt, af Linnaeus kaldet Chiton; met endeel nye Arter og Varieteter. Skrivter af Naturhistorie Selskabet, 4, 62 - 103, pl. 6.","Cooke, A. H. (1885) Report on the Testaceous Mollusca obtained during a dredging excursion in the Gulf of Suez in the months of February and March 1869. Annals and Magazine of Natural History, 16, 262 - 276. https: // doi. org / 10.1080 / 00222938509459881"]}

Ischnochiton yerburyi (E.A. Smith, 1891) (Fig. 4) Chiton (Ischnochiton) yerburyi E.A. Smith 1891, p. 420, pl. 33, fig. 6; Pilsbry 1892, p. 101, pl. 20, fig. 11. Ischnochiton yerburyi; Leloup 1960, p. 35, fig. 5; Ferreira 1983, p. 251, figs 1���2; Strack 1993, p. 9, pl. 3, fig. 2, pl. 7, fig. 3; Bosch et al. 1995, p. 189, fig. sp. 879; Kaas & Van Belle 1998, p. 203; Dekker & Orlin 2000, p. 7; Slieker 2000, p. 46, fig. 9; Abubakr 2004, p. 73; Callea et al. 2005, p. 93; Dell���Angelo et al. 2011b, p. 25; Mohammadian 2011, p. 211, fig. p. 212; Al-Yamani et al. 2012, p. 120, pl. 83; Blatterer 2019, p. 49, pl. 2, fig. 5 a-b. Ischnochiton yerburi (sic); Leloup 1980, p. 10; Vine 1986, p. 125. Ischnochiton (Ischnochiton) yerburyi; Kaas 1986, p. 11, fig. 8; Anseeuw & Terryn 2004, p.7, figs 16���23, 38���39; Dinapoli & Janssen 2009, p. 23, pl. 12a���d; Hekmatara & Heidary Baladehi 2011, p. 1, fig. 2. Ischnochiton (I.) yerburyi; Kaas & Van Belle 1988, p. 116, figs 2���7; Kaas & Van Belle 1990, p. 124, fig. 53, map 21; Dell���Angelo et al. 2004, p. 51, pl. 3, figs 4���7. Ischnochiton (Simplischnochiton) yerburyi; Van Belle & Wranik 1991, p. 368, fig. 13; Van Belle 1994, p. 2. Type material. BMNH 1888.4.9.345. Type locality. Aden. Material examined. Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study): St. 8: 8 valves (1 head and 7 intermediate) (MZB 50589); St. 9: 4 valves (1 head, 2 intermediate and 1 tail), Figs 4 G���I (MZB 50527). Egypt, Hurghada: St. 13: 6 intermediate valves (BD 181); St. 14: 14 valves (1 head, 11 intermediate and 2 tail), Figs 4 A���F (BD 182; MZB 50526; RGM.1356850); St. 14bis: 2 intermediate valves (BD 183); St. 16: 7 valves (1 head, 5 intermediate and 1 tail) (BD 184). Maximum width: 5 / 6.3 / 5.2 mm. Description. Head valve semi-circular, posterior margin widely V-shaped, front slope straight. Intermediate valve rectangular, L/W = 0.36���0.38, front margin sinuous, moderately elevated (H/W = 0.39��� 0.44), anterior profile subcarinated, side margins rounded, posterior margin almost straight, apex hardly or not indicated, lateral areas slightly raised, poorly defined. Tail valve semicircular, L/W = 0.58, front margin weakly convex in jugal part, mucro subcentral, not elevated, antemucronal slope slightly convex, postmucronal slope weakly concave directly behind mucro. Tegmentum coarsely reticulated by a thimble-like sculpture, pits squarish to subromboidal, network finer on the jugal part. Articulamentum with rounded apophyses, jugal sinus straight, relatively wide, insertion plates short, slit formula 11���13/1/11���12, slits deep, teeth inequidistant, smooth. Remarks. A detailed description of this species was given by Kaas & Van Belle (1990). Ferreira (1983) synonymised four other nominal Ischnochiton species from the Indian Ocean with Ischnochiton yerburyi, all having in common a thimble-like sculptured tegmentum. After a thorough examination of the types, Kaas & Van Belle (1990) concluded that at least two species could be distinguished, I. yerburyi with a strong thimble-like sculpture that is apparent even on the head and tail valves, and I. sansibarensis Thiele, 1909 with a weaker net-like sculpture, in which the head and tail valves and lateral areas are evenly granulose-punctate. Other differences in the dorsal girdle scales and in the radula require further investigation (Kaas & Van Belle 1990; Anseeuw & Terryn 2004). We attribute our material to I. yerburyi, despite the valves having a weaker sculpture and the front margin of the figured tail valve (Fig. 4G) being convex, as reported by Thiele (1909: pl. 8, fig. 27) and Kaas & Van Belle (1990: fig. 55/2) for I. sansibarensis. The tail valve figured has 12 slits in the articulamentum (Fig. 4H), which agrees with the number reported by Kaas & Van Belle for I. yerburyi (11���13, vs 8���10 for I. sansibarensis). Moreover, the sculpture of antemucronal and postmucronal areas seems similar (not granulose-punctate as in I. sansibarensis), and agrees with the tail valves figured by Anseeuw & Terryn (2004: fig. 20) and Dinapoli & Janssen (2009: pl. 12d) for I. yerburyi. This is the first report of this species as a fossil. Distribution. Late Pleistocene: Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study); Egypt (Hurghada: this study). Present-day: Indian Ocean, from the north-western Red Sea to the Maldives; African coast from Somalia to Zanzibar, Socotra island to Madagascar, and the Northern Red Sea to Mozambique; Arabian Sea: Pakistan to Yemen (Dinapoli & Janssen 2009; Hekmatara & Heidary Baladehi 2011; Blatterer 2019)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on pages 408-409, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Smith, E. A. (1891) On a collection of marine shells from Aden, with some remarks upon the relationship of the molluscan fauna of the Red Sea and the Mediterranean. Proceedings of the Zoological Society of London, 1891, 390 - 436, pl. 33. https: // doi. org / 10.1111 / j. 1096 - 3642.1891. tb 01764. x","Leloup, E. (1960) Amphineures du golfe d'Aqaba et de la Peninsule Sinai. Sea Fisheries Research Station, Haifa, Bulletin, 29, 29 - 55, pl. 1.","Ferreira, A. J. (1983) Researches on the coast of Somalia. The chiton fauna (Mollusca Polyplacophora). Monitore Zoologico Italiano, 9, 249 - 297. https: // doi. org / 10.1080 / 00269786.1983.11758574","Strack, H. L. (1993) The Polyplacophora of the Red Sea. Journal of the Malacological Society of Australia, 14, 1 - 40. https: // doi. org / 10.1080 / 00852988.1993.11923901","Bosch, D. T., Dance, S. P., Moolenbeek, R. G. & Oliver, P. G. (1995) Seashells of Eastern Arabia. Motivate Publishing, Dubai, 290 pp.","Kaas, P. & Van Belle, R. A. (1998) Catalogue of living chitons (Mollusca, Polyplacophora). Second, revised edition. Backuys Publishers, Leiden, 204 pp.","Dekker, H. & Orlin, Z. (2000) Check-list of Red Sea Mollusca. Spirula, 47 (Supplement), 1 - 46.","Slieker, F. J. A. (2000) Chitons of the world. An illustrated synopsis of recent Polyplacophora. L'Informatore Piceno Ed., Ancona, 154 pp.","Abubakr, M. M. (2004) The Republic of Yemen Marine Biotic Ecosystem (Resources-Habitats and Species). Ministry of Water and Environment, Environment Protection Authority, Aden, 128 pp.","Callea, A., Borri, M., Cianfanelli, S., Martignoni, R. & Volpi, C. (2005) Taxonomic and ecological remarks on the marine molluscs of the Mida Creek area (Kenya, Western Indian Ocean). Atti della Societa italiana di scienze naturali e del Museo civico di storia naturale di Milano, 146, 79 - 94.","Dell'Angelo, B., Prelle, G., Sosso, M. & Bonfitto, A. (2011 b) Intertidal chitons (Mollusca: Polyplacophora) from southern Madagascar. African Invertebrates, 52, 21 - 37. https: // doi. org / 10.5733 / afin. 052.0103","Mohammadian, H. (2011) The molluscs in Iran. Shabpareh Publishing Company, Tehran, 229 pp. [in Arabic script]","Al-Yamani, F., Skryabin, V., Boltachova, N., Revkov, N., Makarov, M., Grintsov, V. & Kolesnikova, E. (2012) Illustrated Atlas on the Zoobenthos of Kuwait. Kuwait Institute for Scientific Research, Kuwait, 17 + 384 pp.","Blatterer, H. (2019) Mollusca of the Dahab region. Oberosterreichisches Landesmuseum, Linz, Austria, 480 pp.","Leloup, E. (1980) Chitons de la Mer Rouge, du golfe de Suez et de la Mediterranee. Bulletin Institut Royale des Sciences Naturelles de Belgique, 52, 1 - 14, 2 pls.","Vine, P. (1986) Red Sea Invertebrates. IMMEL Publishing, London, 224 pp.","Kaas, P. (1986) Revision of the chitons (Mollusca: Polyplacophora) from the coral-reefs of Tulear, SW Madagascar, and of the Mascarene Islands. Mesogee, 46, 9 - 23.","Anseeuw, B. & Terryn, Y. (2004) Intertidal chitons (Mollusca: Polyplacophora) from the coast of Jordan, Red Sea, with the description of a new species of Parachiton Thiele, 1909. Bollettino Malacologico, Supplement 5, 1 - 24.","Dinapoli, A. & Janssen, R. (2009) Polyplacophora (Mollusca) of the Socotra Arcipelago - Systematics and Biogeography. Fauna of Arabia, 24, 1 - 46.","Hekmatara, M. & Heidary Baladehi, M. H. (2011) New record of Ischnochiton (Ischnochiton) yerburyi (Mollusca: Polyplacophora) from Chabahar Bay, Iranian coast of Oman Sea. Marine Biodiversity Records, 4, 1 - 3. https: // doi. org / 10.1017 / S 1755267211000789","Kaas, P. & Van Belle, R. A. (1988) Chitons (Mollusca: Polyplacophora) from the coasts of Oman and the Arabian Gulf. American Malacological Bulletin, 6, 115 - 130.","Kaas, P. & Van Belle, R. A. (1990) Monograph of Living Chitons (Mollusca: Polyplacophora). Volume 4. Suborder Ischnochitonina: Ischnochitonidae: Ischnochitoninae (continued). Additions to Volumes 1, 2 and 3. E. J. Brill, Leiden, 298 pp.","Dell'Angelo, B., Bonfitto, A., Sabelli, B. & Taviani, M. (2004) Chitons (Mollusca, Polyplacophora) from bioclastic sands of the Ifaty-Tulear back reefs (Madagascar, Western Indian Ocean). Bollettino Malacologico, Supplment 5, 45 - 62.","Van Belle, R. A. & Wranik, W. (1991) Chitons (Mollusca: Polyplacophora) from the Coasts of Yemen and Socotra Island. Fauna of Saudi Arabia, 12, 366 - 381.","Van Belle, R. A. (1994) On the chiton fauna of Bahrain, Arabian Gulf. Gloria Maris, 33, 1 - 6.","Thiele, J. (1909) Revision des Systems der Chitonen. Zoologica, 22, 1 - 132, pls. 1 - 10. https: // doi. org / 10.5962 / bhl. title. 11245"]}

Callochiton sp. (Fig. 6) Material examined. Egypt, Hurghada: St. 13: 1 intermediate valve, width 4 mm, Figs 6 A���D (MZB 50529). Description. Intermediate valves trapezoidal, rounded in anterior profile, elevated (height/width ratio 0.61), anterior margin almost straight in jugal area, lateral areas weakly raised. Tegmentum surface appears rough, sculptured with fine granules, fusing into continuous longitudinal lines in central area, radially in lateral areas. Articulamentum with short, wide apophyses connected at jugum by lamina, insertion plates short, with two slits, slit rays visible. Remarks. This intermediate valve is characterised by the lack of longitudinal grooves on the pleural area (as in C. vanninii), the rounded anterior profile and the strong elevation (H/W = 0.61), higher than that seen in intermediate valves of C. vanninii (H/W = 0.30���0.48). These characters do not agree with those of the other named Indian Ocean Callochiton species, C. clausadeae Kaas & Van Belle, 1985b (from Madagascar, Mauritius, R��union, and the Maldive Islands), C. levatus Kaas & Van Belle, 1998 (from Madagascar, R��union, Mauritius and Chagos Archipelago) and C. christamariae Schwabe, 2003 (from Mauritius). Two fossil species of Callochiton have a similar dorsal elevation. Callochiton calcatus Dell���Angelo & Palazzi, 1994 (H/W = 0.65���0.72), known from the Recent Mediterranean and the submerged Pleistocene of the Tyrrhenian Sea geographic area between Capraia and Capo Corso, Italy (Dell���Angelo & Giusti 1997), differs from Callochi- ton sp. mainly by the presence of longitudinal grooves on the pleural areas and the more angulated intermediate valves. Callochiton pouweri Dell���Angelo, Landau, Van Dingenen & Ceulemans, 2018b (H/W = 0.58���0.64), known from the upper Miocene of Anjou, France, differs from Callochiton sp. mainly by the presence of longitudinal grooves on the pleural areas and the valves being carinated in anterior profile. Distribution. Late Pleistocene: Egypt (Hurghada: this study)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on pages 411-412, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Kaas, P. & Van Belle, R. A. (1985 b) Monograph of Living Chitons (Mollusca: Polyplacophora). Vol. 2. Suborder Ischnochi- tonina, Ischnochitonidae: Schizoplacinae, Callochitoninae & Lepidochitoninae. E. J. Brill, W. Backhuys, Leiden, 198 pp.","Kaas, P. & Van Belle, R. A. (1998) Catalogue of living chitons (Mollusca, Polyplacophora). Second, revised edition. Backuys Publishers, Leiden, 204 pp.","Schwabe, E. (2003) Taxonomic notes on chitons. 3. Notes on the genus Callochiton Gray, 1847 (Mollusca: Polyplacophora: Callochitonidae) from the Indian Ocean. Malakologische Abhandlungen, 21, 19 - 27.","Dell'Angelo, B. & Palazzi, S. (1994) Callochiton calcatus n. sp. con note su Callochiton septemvalvis (Montagu, 1803). La Conchiglia, 26 (273), 15 - 23.","Dell'Angelo, B. & Giusti, F. (1997) I Polyplacophora di una tafocenosi profonda. La Conchiglia, 29 (283), 51 - 58.","Dell'Angelo, B., Landau, B., Van Dingenen, F. & Ceulemans, F. (2018 b) The upper Miocene chitons of northwest France (Mollusca: Polyplacophora). Zootaxa, 4447 (1), 1 - 62. https: // doi. org / 10.11646 / zootaxa. 4447.1.1"]}

Acanthochitona mastalleri Strack, 1989 (Fig. 19) Acanthochiton mastalleri Strack 1989, p. 169, textfig. 1, pls. 19, 20; Strack 1993, p. 25, pl. 5, fig. 7; Schwabe 1997, p. 28, unnumbered figs at p. 30; Kaas & Van Belle 1998, p. 119; Dekker & Orlin 2000, p. 7; Slieker 2000, p. 52, fig. 36; Anseeuw & Terryn 2004, p. 20, figs 58���59; Dell���Angelo et al. 2010a, p. 20; Blatterer 2019, p. 56, pl. 5, fig. 12 a-f. Type material. Holotype: ZMA Moll. 388029, a specimen preserved in ethanol from Merlin Point, Hurghada, Egypt. Paratypes: many specimens in several institutions (Strack 1989). Type locality. Merlin Point, 4 km South of Hurghada, Egypt. Material examined. Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study): St. 8: 2 tail valves, Figs 19 G-I (MZB 50558); St. 9: 2 valves (1 head and 1 tail), Figs 19 A���B, 19E���F (MZB 50557). Egypt, Hurghada: St. 13: 6 valves (5 intermediate and 1 tail) (BD 225); St. 14: 4 valves (1 head and 3 intermediate), Figs 19 C���D (BD 226; MZB 50559); St. 14bis: 1 intermediate valve (BD 227); St. 16: 2 intermediate valves (BD 228). Maximum width: 3.7 / 3.9 / 3.2 mm. Description. Head valve semicircular. Intermediate valve wing-shaped, posterior margin concave on both sides of well developed apex, jugal area raised, narrow, striated, sharply separated from lateropleural areas, anterior end of jugum protruding sinus, lateropleural areas much reduced, their front margins deeply concave. Tail valve broad, antemucronal area reduced as in intermediate valves, mucro subcentral, prominent, antemucronal and postmucronal slopes almost straight, forming angle of 134���141��. Tegmentum densely covered with irregular, more or less oval, flat topped granules, except in jugal area, Articulamentum with apophyses extraordinarily large, insertion plates well developed, strongly protruding on intermediate valves, expanded and completely surrounding tail valve, except for jugal margin, slit formula 5/1/2. Remarks. Detailed descriptions of this species were given by Strack (1989) and Anseeuw & Terryn (2004). Acanthochitona mastalleri Strack, 1989 is characterised by the tegmentum reduced in lateropleural areas, with markedly concave anterolateral margins, sculptured with irregular, more or less oval, flat-topped granules, and by a very wide girdle, partially extending over the valves. Our valves agree with the description and figures of the valves given by Strack (1989), but with slight differences in the shape of the tail valves (Figs19E, G): they are less elongate than the valve figured by Strack (1989: fig. 4), and also the granules seem more irregular roundish, less elongate. Notwithstanding these slight differences, we consider our valves conspecific with Acanthochitona mastalleri. This is the first report of this species as a fossil. Distribution. Late Pleistocene: Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study); Egypt, Hurghada (this study). Present-day: Indian Ocean: Red Sea, Oman and Kenya (Anseeuw & Terryn 2004; Blatterer 2019)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on pages 431-433, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Strack, H. L. (1989) Description of a new Acanthochitona species (Polyplacophora) from the Red Sea. Journal of Conchology, 33, 169 - 172, pls. 19 - 20.","Strack, H. L. (1993) The Polyplacophora of the Red Sea. Journal of the Malacological Society of Australia, 14, 1 - 40. https: // doi. org / 10.1080 / 00852988.1993.11923901","Schwabe, E. (1997) Beitrag zur Kenntnis einiger Kaferschnecken (Polyplacophora) des Roten Meeres. Club Conchylia Informationen, 29, 25 - 30.","Kaas, P. & Van Belle, R. A. (1998) Catalogue of living chitons (Mollusca, Polyplacophora). Second, revised edition. Backuys Publishers, Leiden, 204 pp.","Dekker, H. & Orlin, Z. (2000) Check-list of Red Sea Mollusca. Spirula, 47 (Supplement), 1 - 46.","Slieker, F. J. A. (2000) Chitons of the world. An illustrated synopsis of recent Polyplacophora. L'Informatore Piceno Ed., Ancona, 154 pp.","Anseeuw, B. & Terryn, Y. (2004) Intertidal chitons (Mollusca: Polyplacophora) from the coast of Jordan, Red Sea, with the description of a new species of Parachiton Thiele, 1909. Bollettino Malacologico, Supplement 5, 1 - 24.","Dell'Angelo, B., Gori, S., Baschieri, L. & Bonfitto, A. (2010 a) Chitons (Mollusca, Polyplacophora) from the Maldive islands. Zootaxa, 2673 (1), 1 - 38. https: // doi. org / 10.11646 / zootaxa. 2673.1.1","Blatterer, H. (2019) Mollusca of the Dahab region. Oberosterreichisches Landesmuseum, Linz, Austria, 480 pp."]}

Genus Acanthochitona Gray 1821 Type species. Chiton fascicularis Linnaeus, 1767, by monotypy. Distribution. Almost worldwide except polar waters. The fossil record extends back to the Miocene of the Mediterranean Basin (Dell���Angelo et al. 2016, 2018a, b), Paratethys (��ulc 1934; Bałuk 1984), West Pacific Islands (Ladd 1966), and Australia (Cotton 1964)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on page 430, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Gray, J. E. (1821) A natural arrangement of Mollusca, according to their internal structure. The London Medical Repository, 15, 229 - 239.","Linnaeus, C. (1767) \" Vermes Testacea \". In: Systema Naturae. Editio duodecima, reformata. 1 (2). L. Salvii, Holmiae, pp. 533 - 1327.","Dell'Angelo, B., Giuntelli, P., Sosso, M. & Zunino, M. (2016) Polyplacophora from the Miocene of North Italy. Part 2: Callochitonidae, Chitonidae, Lepidochitonidae, Acanthochitonidae and Cryptoplacidae. Rivista Italiana di Paleontologia e Stratigrafia, 122, 23 - 54.","Dell'Angelo, B., Lesport, J. - F., Cluzaud, A. & Sosso, M. (2018 a) The Oligocene to Miocene chitons (Mollusca: Polyplacophora) of the Aquitaine Basin, southwestern France, and Ligerian Basin, western France. Part 1: Leptochitonidae, Hanleyidae, Ischnochitonidae, Chitonidae, Spinochitonidae fam. nov. and Schizochitonidae. Bollettino Malacologico, 54, 1 - 47.","Sulc, J. (1934) Studien uber die fossilen Chitonen. I. Die fossilen Chitonen im Neogen des Wiener Beckens und der angrenzenden Gebiete. Annalen des Naturhistorischen Museums in Wien, 47, 1 - 31, pls. 1 - 2.","Baluk, W. (1984) Additional data on chitons and cuttlefish from the Korytnica clays (Middle Miocene; Holy Cross Mountains, Central Poland). Acta Geologica Polonica, 34, 281 - 297, pls. 1 - 17.","Ladd, H. S. (1966) Chitons and Gastropods (Haliotidae through Adeorbidae) from the western Pacific islands. Geological Survey Professional Paper, 531, 1 - 98, 16 pls. https: // doi. org / 10.3133 / pp 531","Cotton, B. C. (1964) South Australian Mollusca. Chitons. Handbook of the Flora and Fauna of South Australia, Adelaide, 151 pp"]}

Genus Ischnochiton Gray, 1847 Type species. Chiton textilis Gray, 1828, by subsequent designation (Gray 1847: 168). For synonymy, see Kaas & Van Belle (1990). Remarks. The diagnosis of subgenera within Ischnochiton is based mainly on girdle characters, not detectable in fossil species. Distribution. Ischnochiton is one of the most ancient extant genera, with a present-day circumglobal distribution, excluding the northern Atlantic and Arctic Oceans (Kaas & Van Belle 1990). Beside a questionable record from the Jurassic of Germany (Ischnochiton marloffsteinensis Fiedel & Keupp, 1988), the genus is present in the Eocene of Europe (England and Ukraine), the upper Eocene-lower Oligocene of Washington, U.S.A. (Dell���Angelo et al. 2011a), the Miocene to Pleistocene of Europe (Dell���Angelo et al. 2004, 2015; Garilli et al. 2005; Studencka & Dulai 2010), Africa (Tanzania, Davis 1954), Australasia (Ashby & Cotton 1939; Cotton & Godfrey 1940; Beu & Maxwell 1990), Indonesia (Verbeek et al. 1882), Japan (Itoigawa et al. 1976) and the U.S.A. (Berry 1940). Ischnochiton sp. is the only chiton species reported from deep waters (> 400 m) in the Red Sea (Janssen & Taviani 2015)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on pages 407-408, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Gray, J. E. (1847) A list of the genera of Recent Mollusca, their synonyms and types. Proceedings of the Zoological Society of London, 15, 129 - 206. https: // doi. org / 10.1111 / j. 1469 - 7998.1847. tb 00164. x","Gray, J. E. (1828) Spicilegia Zoologica; or original figures and short systematic descriptions of new and unfigured animals. Vol. 1. Treuttel, Wurtz and Co., London, 2 pp., pls. 3, 6. [pp. 5 - 6]","Kaas, P. & Van Belle, R. A. (1990) Monograph of Living Chitons (Mollusca: Polyplacophora). Volume 4. Suborder Ischnochitonina: Ischnochitonidae: Ischnochitoninae (continued). Additions to Volumes 1, 2 and 3. E. J. Brill, Leiden, 298 pp.","Fiedel, U. & Keupp, H. (1988) Ischnochiton marloffsteinensis n. sp., eine Polyplacophore aus dem Frankischen Lias. Palaontologische Zeitschrift, 62, 49 - 58. https: // doi. org / 10.1007 / BF 02989833","Dell'Angelo, B., Bonfitto, A. & Taviani, M. (2011 a) Chitons (Polyplacophora) from Paleogene strata in Western Washington State, U. S. A. Journal of Paleontology, 85, 936 - 954. https: // doi. org / 10.1666 / 10 - 114.1","Dell'Angelo, B., Bonfitto, A., Sabelli, B. & Taviani, M. (2004) Chitons (Mollusca, Polyplacophora) from bioclastic sands of the Ifaty-Tulear back reefs (Madagascar, Western Indian Ocean). Bollettino Malacologico, Supplment 5, 45 - 62.","Dell'Angelo, B., Giuntelli, P., Sosso, M. & Zunino, M. (2015) Polyplacophora from the Miocene of North Italy. Part 1: Leptochitonidae, Hanleyidae, Ischnochitonidae and Callistoplacidae. Rivista Italiana di Paleontologia e Stratigrafia, 121, 217 - 242.","Garilli, V., Dell'Angelo, B. & Vardala-Theodorou, E. (2005) Polyplacophora from the Pleistocene of Kyllini (NW Peloponnese, Greece). Bollettino della Societa Paleontologica Italiana, 44, 117 - 134.","Studencka, B. & Dulai, A. (2010) Chitons (Mollusca: Polyplacophora) from the Middle Miocene sandy facies of Ukraine, Central Paratethys. Acta Geologica Polonica, 60, 257 - 274.","Davis, A. G. (1954) Lower Miocene Chitons from Mafia Island, East Africa. Proceedings of the Malacological Society of London, 31, 17 - 20.","Ashby, E. & Cotton, B. C. (1939) New fossil chitons from the Miocene and Pliocene of Victoria. Records of the South Australian Museum, 6, 209 - 242, pls. 19 - 21.","Cotton, B. C. & Godfrey, F. K. (1940) Australian Fossil Chitons. In: Handbook, Molluscs of South Australia. Pt. 2. South Australian Museum, Adelaide, pp. 569 - 590.","Beu, A. G. & Maxwell, P. A. (1990) Cenozoic Mollusca of New Zealand. New Zealand Geological Survey Paleontological Bulletin, 58, 1 - 518.","Verbeek, R. D. M., Boettger, O. & Fritsch, K. von (1882) Die Conchylien der Mittelmiocaen-Schichten Sud-Sumatra's. In: Die Tertiarformation von Sumatra und ihre Thierreste. Palaeontographica, Supplement III (II Theil), 34 - 102, pls. 1 - 8.","Itoigawa, J., Kuroda, M., Naruse, A. & Nishimoto, H. (1976) Polyplacophora assemblages from the Pleistocene formations of Boso and Miura Peninsulas, environs of Tokyo, Japan. Bulletin of the Mizunami Fossil Museum, 3, 171 - 204.","Berry, C. T. (1940) Some fossil Amphineura from the Atlantic coastal plain of North America. Proceedings of the Academy of Natural Sciences of Philadelphia, 91, 207 - 217, pls. 9 - 12.","Janssen, R. & Taviani, M. (2015) Taxonomic, Ecological and Historical Considerations on the Deep-Water Benthic Mollusc Fauna of the Red Sea. In: Rasul, N. M. A. & Stewart, I. C. F. (Eds.), The Red Sea. Springer Earth System Sciences, Springer- Verlag, Berlin & Heidelberg, pp. 511 - 529. https: // doi. org / 10.1007 / 978 - 3 - 662 - 45201 - 1 _ 29."]}

Acanthochitona interglacialis n. sp. (Fig. 20) Type material. Holotype: MZB 50560, an intermediate valve, width 1.6 mm (Figs 20 A���C). Type locality. Saudi Arabia, Gulf of Aqaba, Ash Shaykh Humayd: St. 8. Type stage. Late Pleistocene, last interglacial MIS5e. Etymology. The name refers to the stratigraphic occurrence of the available material (interglacial deposits). Diagnosis. Intermediate valve pentagonal, elevated, rounded in anterior profile, posterior margin slightly concave either side of strongly protruding apex. Tegmentum sculptured with elongated, flattened pustules of variable size. Articulamentum with apophyses projecting forward, insertion plate short with one slit on each side. Description. Intermediate valve pentagonal, elevated (H/W = 0.55), rounded in anterior profile, anterior margin strongly concave in jugal part, posterior margin slightly concave on both sides of strongly protruding apex. Tegmentum sculptured with elongated, widely-spaced, irregularly arranged, flattened pustules, of variable size, up to 100 ��m in length, with up to 13 microaesthetes irregularly disposed. Articulamentum with apophyses projecting forward, insertion plate short with short, narrow slits, one on each side. Remarks. A single intermediate valve is present in the studied material that superficially resembles an intermediate valve of the genus Acanthochitona, but without a well developed jugal area. The jugal area is in continuity with the pleural areas and not separate, and it has the same type of sculpture formed by large granules, albeit more irregular and less evident. The elevation of the valve is an uncommon character in Acanthochitona. We therefore describe this unique intermediate valve as a new species. The attribution to the genus Acanthochitona is tentative, based on the great similarity of this valve with intermediate valves pertaining to Acanthochitona. Other living species of Acanthochitona without a well defined jugal area are known, i.e. Acanthochitona sp. (Sirenko 2012: 98, fig. 33) and A. lanae Sirenko & Saito, 2017 (Sirenko & Saito 2017: fig. 30), both from Vietnam, but this could be the first report (B. Sirenko, pers. comm.) of a fossil species of Acanthochitona with this feature. Distribution. Late Pleistocene: Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on page 433, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Sirenko, B. I. (2012) Chitons (Mollusca, Polyplacophora) of Nhatrang Bay, South Vietnam. In: Britayev, T. A. & Pavlov, D. S. (Eds.), Benthic fauna of the Bay of Nhatrang, Southern Vietnam. Vol. 2. KMK, Moscow, pp. 56 - 122.","Sirenko, B. I. & Saito, H. (2017) New species of chitons of the superfamily Cryptoplacoidea (Mollusca: Polyplacophora) from Vietnamese waters. Zootaxa, 4299 (4), 451 - 506. https: // doi. org / 10.11646 / zootaxa. 4299.4.1"]}

Choneplax indica Odhner, 1919 (Fig. 22) Choneplax indicus Odhner 1919, p. 40, pl. 3, figs 44-45. Choneplax indica; Bergenhayn 1931, p. 3, pl. 1, figs 5���9; Kaas 1985, p. 331, 339; Kaas 1986, p. 20, figs 67���72; Kaas & Van Belle 1998, p. 95; Slieker 2000, p. 50, fig. 32; Sirenko 2003, p. 33, 35, fig. 11; Dell���Angelo et al. 2004, p. 58, pl. 6, figs 8���13; Schwabe 2004, p. 3160, figs 11���13, 17D; Sirenko 2006, fig. 8A; Dinapoli & Janssen 2009, p. 31, pl. 16 a���c; Dell���Angelo et al. 2010b, p. 40, fig. 4H; Blatterer 2019, p. 56, pl. 6, fig. 15a-l. Type material. Holotype: SMNH 1324, indicated as syntype (fide Schwabe 2004: 3160). Type locality. Tamatave, Madagascar. Material examined. Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study): St. 2: 1 tail valve (MZB 60264); St. 4: 2 intermediate valves (MZB 60265); St. 7: 1 intermediate valve (MZB 60266); St. 8: 37 valves (1 head, 30 intermediate and 6 tail) (MZB 60267); St. 9: 6 valves (1 intermediate and 5 tail), Figs 22 H���I (MZB 50564); St. 10: 2 intermediate valves (MZB 60268). Egypt, (Hurghada): St. 12: 50 valves (3 head, 40 intermediate and 7 tail) (BD 229): St. 13: 306 valves (15 head, 216 intermediate and 75 tail), Figs 22 A���G, 22J���L (BD 230; MZB 50563; RGM.1356862). Egypt, Hamata: St. 18: 1 intermediate valve (MZB 60273). Maximum width: 1.6 / 2.6 / 2.4 mm. Description. Head valve semielliptical, apex hardly developed, sculptured with very large granules arranged in quincunx. Intermediate valve elliptical in shape, more or less elongated, jugal area narrow, smooth, from triangular to almost rectangular, growth lines clearly visible, sculptured with granules arranged in longitudinal lines in pleurolateral areas and end without overlapping along the smooth, wedge-shaped jugum Tail valve with mucro situated terminally, not elevated and inconspicuous, antemucronal area sculptured like intermediate valves, but jugum less wedge-shaped, postmucronal area lacking. Tegmentum surface completely granulated, except for smooth jugal area, macroaesthetes of granules posteriorly situated and surrounded by five microaesthetes. Articulamentum with apophyses rather large and triangular, directed laterally in intermediate valves, much shorter and closer-set in tail valve, slit formula 3/0/0, slits in head valve very short, slit rays visible in head valve only. Remarks. A detailed description of this species was given by Schwabe (2004). Choneplax indica Odhner, 1919 is characterised by elongate, convex valves, with raised, smooth jugum and elliptical granules, sometimes coalescent, arranged in longitudinal rows diverging forward from the apex in latero-pleural areas. Choneplax indica is the most common species found in the Hurghada localities St. 12 and St. 13 (356 valves, 31.6% of the total number of valves). The examined specimens fully agree with descriptions and figures provided by Kaas (1986), Dell���Angelo et al. (2004), Schwabe (2004) and Dinapoli & Janssen (2009). The granules are roundish, similar to those figured by Schwabe (2004: fig. 11C) in intermediate valves, a central macroaesthete is clearly visibile, whereas the microesthetes are not visible due to erosion and adherent matrix. Some intermediate valves (Fig. 22H) match well with the valve figured by Schwabe (2004: fig. 11B) as second intermediate valve. Leloup (1981) described two other species of Choneplax from Madagascar, C. parvus, and C. sp., both discussed at length by Kaas (1986), who considered them to represent synonyms of C. indica. The valves of Choneplax indica resemble those of Cryptoplax sykesi in many respects. Whilst complete living specimens of both species are easily separable, it is more difficult to separate single valves. Choneplax (attributed to the family Acanthochitonidae, see Sirenko 2006 and Irisarri et al. 2014) differs from Cryptoplax (attributed to the family Cryptoplacidae) in the strong imbrications of all the valves, and most importantly in the different characters of girdle. Sirenko (2003) suggested that the evolution of the superfamily Cryptoplacoidea (which includes three families: Acanthochitonidae, Cryptoplacidae, and Hemiarthridae) can be connected to a reduction of the tegmentum and, as a result, a reduction of slits on the insertion plates. This is the first fossil record of the species. Distribution. Late Pleistocene: Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study); Egypt, (Hurghada, Hamata: this study). Present-day: Leven Bank (North of Mozambique Channel), Madagascar, R��union, Mauritius, and Rodrigues (Mascarene Islands), Socotra island (Dell���Angelo et al. 2010b; Blatterer 2019)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on pages 435-437, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Odhner, N. H. (1919) Contribution a la faune malacologique de Madagascar. Arkiv for Zoologi, 12, 1 - 52, pls. 1 - 4. https: // doi. org / 10.5962 / bhl. part. 789","Bergenhayn, J. R. M. (1931) Uber die Morphologie und Philogenie der Gattung Choneplax Carpenter (Ordo Loricata sive Polyplacophora). Arkiv for Zoologi, 22 A, 1 - 6, pl. 1.","Kaas, P. (1986) Revision of the chitons (Mollusca: Polyplacophora) from the coral-reefs of Tulear, SW Madagascar, and of the Mascarene Islands. Mesogee, 46, 9 - 23.","Kaas, P. & Van Belle, R. A. (1998) Catalogue of living chitons (Mollusca, Polyplacophora). Second, revised edition. Backuys Publishers, Leiden, 204 pp.","Slieker, F. J. A. (2000) Chitons of the world. An illustrated synopsis of recent Polyplacophora. L'Informatore Piceno Ed., Ancona, 154 pp.","Sirenko, B. I. (2003) First Pacific species of the genus Choneplax (Mollusca: Polyplacophora). Ruthenica, 13, 33 - 39.","Dell'Angelo, B., Bonfitto, A., Sabelli, B. & Taviani, M. (2004) Chitons (Mollusca, Polyplacophora) from bioclastic sands of the Ifaty-Tulear back reefs (Madagascar, Western Indian Ocean). Bollettino Malacologico, Supplment 5, 45 - 62.","Schwabe, E. (2004) The Polyplacophora (Mollusca) collected during the First International Marine Biodiversity Workshop for Rodrigues (western Indian Ocean), with the description of a new species. Journal of Natural History, 38, 3143 - 3173. https: // doi. org / 10.1080 / 00222930410001695114","Sirenko, B. I. (2006) New outlook on the system of chitons (Mollusca: Polyplacophora). Venus, 65, 27 - 49.","Dinapoli, A. & Janssen, R. (2009) Polyplacophora (Mollusca) of the Socotra Arcipelago - Systematics and Biogeography. Fauna of Arabia, 24, 1 - 46.","Dell'Angelo, B., Sabelli, B., Taviani, M. & Bonfitto, A. (2010 b) New data on the Polyplacophora of Madagascar (Western Indian Ocean) (Mollusca: Polyplacophora). Archiv fur Molluskenkunde, 139, 35 - 43. https: // doi. org / 10.1127 / arch. moll / 1869 - 0963 / 139 / 035 - 043","Blatterer, H. (2019) Mollusca of the Dahab region. Oberosterreichisches Landesmuseum, Linz, Austria, 480 pp.","Leloup, E. (1981) Chitons de Tulear, Reunion, Maurice et Tahiti. Bulletin Institut Royale des Sciences Naturelles de Belgique, 53, 1 - 46, 4 pls.","Irisarri, I., Eernisse, D. J. & Zardoya, R. (2014) Molecular phylogeny of Acanthochitonina (Mollusca: Polyplacophora: Chitonida): three new mitochondrial genomes, rearranged gene orders and systematics. Journal of Natural History, 48 (45 - 48), 2825 - 2853. https: // doi. org / 10.1080 / 00222933.2014.963721"]}

Rhyssoplax maldivensis (E.A. Smith, 1903) (Fig. 8) Ischnochiton maldivensis E.A. Smith 1903, p. 596, 619, pl. 36, figs 7���10. Chiton (Rhyssoplax) maldivensis; Van Belle & Wranik 1991, p. 374, fig. 19; Strack 1993, p. 15, pl. 4, fig. 2, pl. 7, figs 10���16; Schwabe 1997, p. 26, unnumbered figs p. 29; Kaas & Van Belle 1998, p. 118; Dekker & Orlin 2000, p. 7; Slieker 2000, p. 48, fig. 20; Anseeuw & Terryn 2004, p. 14, figs 44���45; Kaas et al. 2006, p. 170, fig. 63, maps 11, 32; Schwabe & Lozouet 2006, p. 625. Chiton maldivensis; Hylleberg & Kilburn 2002, p. 21; Abubakr 2004, p. 73. Rhyssoplax maldivensis; Dell���Angelo et al. 2010a, p. 13, figs 4G���I; Sirenko & Schwabe 2011, p. 119; Blatterer 2019, p. 52, pl. 3, fig. 8 a-f. Rhyssoplax cf. maldivensis; Sirenko 2012, p. 78, fig. 20 A���G; Sirenko 2016, p. 483, figs 1���3, 13B, C. Type material. BMNH 1903.9.17.26. Type locality. Felidu Atoll, Maldive Archipelago. Material examined. Eritrea, Massawa (AGIP Exp., St. 21): 1 intermediate valve (MGGC). Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd): St. 2: 2 intermediate valves (MZB 50597); St. 5: 2 intermediate valves (MZB 50598); St. 7: 10 valves (2 head and 8 intermediate) (MZB 50599); St. 8: 17 valves (15 intermediate and 2 tail) (MZB 50600); St. 9: 11 valves (2 head, 8 intermediate and 1 tail) (MZB 60251): St. 10: 2 intermediate valves (MZB 60252); St. 11: 1 tail valve (MZB 60253). Egypt (Hurghada): St. 12: 30 valves (5 head, 21 intermediate and 4 tail) (BD 192); St. 13: 233 valves (31 head, 160 intermediate and 42 tail), Figs 8 A���I (BD 193; MZB 50532; RGM.1356853); St. 14: 21 valves (2 head, 17 intermediate and 2 tail) (BD 194); St. 14bis: 2 intermediate valves (BD 195); St. 15: 1 intermediate valve (BD 196); St. 16: 55 valves (8 head, 43 intermediate and 4 tail) (BD 197). Egypt, Hamata: St. 18: 1 head valve (MZB 60272). Maximum width: 3.4 / 4.5 / 3.8 mm. Description. Head valve semicircular, posterior margin widely V-shaped, front slope slightly convex. Intermediate valves rectangular, front margin slightly convex, highly elevated (H/W = 0.45���0.48), anterior profile rounded to subcarinated, side margins little rounded, posterior margin straight at both sides of the well defined apex, lateral areas raised. Tail valve semi-circular, length about half the width (L/W = 0.50���0.51), front margin straight or slightly convex, posterior margin rather angular, mucro subcentral, prominent, antemucronal and postmucronal slopes almost straight. Head valve, lateral areas of intermediate valves and postmucronal area of tail valve smooth, except for microsculpture and concentric growth lines, central areas with 5���8 longitudinal sulci at both sides of smooth jugum, innermost sulci not reaching front margin of valve. Articulamentum with wide and rounded apophyses, jugal sinus rather narrow, provided with short, finely dentate plate, slit formula 8���10/1/10���13, teeths irregular, inequidistant, outer edge minutely denticulate, slit rays indicated, eaves narrow, porous. Remarks. A detailed description of this species was given by Kaas et al. (2006). This species has occasionally been recorded (i.e. Leloup 1960, 1980) as Chiton (Rhyssoplax) corallinus (Risso, 1826), a well known Mediterranean species that has little in common with R. maldivensis (see Strack 1993; Kaas et al. 2006). This is the first report of this species as a fossil. Distribution. Late Pleistocene: Eritrea, Massawa; Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd); Egypt, (Hurghada, Hamata: this study). Present-day: Indian Ocean: Red Sea, Gulf of Aden, India, Sri Lanka, the Maldive Archipelago and South Vietnam (Kaas et al. 2006; Sirenko 2016; Blatterer 2019)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on pages 414-415, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Smith, E. A. (1903) Marine Mollusca. In: Gardiner, J. S., The Fauna and Geography of the Maldive and Laccadive Archipelagoes. Cambridge University Press, Cambridge, pp. 589 - 630, pls. 35 - 36.","Van Belle, R. A. & Wranik, W. (1991) Chitons (Mollusca: Polyplacophora) from the Coasts of Yemen and Socotra Island. Fauna of Saudi Arabia, 12, 366 - 381.","Strack, H. L. (1993) The Polyplacophora of the Red Sea. Journal of the Malacological Society of Australia, 14, 1 - 40. https: // doi. org / 10.1080 / 00852988.1993.11923901","Schwabe, E. (1997) Beitrag zur Kenntnis einiger Kaferschnecken (Polyplacophora) des Roten Meeres. Club Conchylia Informationen, 29, 25 - 30.","Kaas, P. & Van Belle, R. A. (1998) Catalogue of living chitons (Mollusca, Polyplacophora). Second, revised edition. Backuys Publishers, Leiden, 204 pp.","Dekker, H. & Orlin, Z. (2000) Check-list of Red Sea Mollusca. Spirula, 47 (Supplement), 1 - 46.","Slieker, F. J. A. (2000) Chitons of the world. An illustrated synopsis of recent Polyplacophora. L'Informatore Piceno Ed., Ancona, 154 pp.","Anseeuw, B. & Terryn, Y. (2004) Intertidal chitons (Mollusca: Polyplacophora) from the coast of Jordan, Red Sea, with the description of a new species of Parachiton Thiele, 1909. Bollettino Malacologico, Supplement 5, 1 - 24.","Kaas, P., Van Belle, R. A. & Strack, H. L. (2006) Monograph of Living Chitons (Mollusca: Polyplacophora). Volume 6. Suborder Ischnochitonina (concluded): Schizochitonidae; Chitonidae. Additions to Volumes 1 - 5. E. J. Brill, Leiden-Boston, 463 pp.","Schwabe, E. & Lozouet, P. (2006) Chitons (Mollusca, Polyplacophora) from Rapa, the southernmost island of Polynesia. Zoosystema, 28, 617 - 633.","Hylleberg, J. & Kilburn, R. N. (2002) Annotated inventory of molluscs from the Gulf of Mannar and vicinity. Phuket Marine Biological Center Special Publication, 26, 19 - 79.","Abubakr, M. M. (2004) The Republic of Yemen Marine Biotic Ecosystem (Resources-Habitats and Species). Ministry of Water and Environment, Environment Protection Authority, Aden, 128 pp.","Dell'Angelo, B., Gori, S., Baschieri, L. & Bonfitto, A. (2010 a) Chitons (Mollusca, Polyplacophora) from the Maldive islands. Zootaxa, 2673 (1), 1 - 38. https: // doi. org / 10.11646 / zootaxa. 2673.1.1","Sirenko, B. I. & Schwabe, E. (2011) Description of a minute new chiton (Mollusca, Polyplacophora) from Sri Lanka. Ruthenica, 21, 113 - 121.","Blatterer, H. (2019) Mollusca of the Dahab region. Oberosterreichisches Landesmuseum, Linz, Austria, 480 pp.","Sirenko, B. I. (2012) Chitons (Mollusca, Polyplacophora) of Nhatrang Bay, South Vietnam. In: Britayev, T. A. & Pavlov, D. S. (Eds.), Benthic fauna of the Bay of Nhatrang, Southern Vietnam. Vol. 2. KMK, Moscow, pp. 56 - 122.","Sirenko, B. I. (2016) Chapter 10. A supplement to the recent Chitonidae (Mollusca: Polyplacophora) of Vietnam. In: Adrianov, A. V. & Lutaenko, K. A. (Eds.), Biodiversity of the western part of the South China Sea. Dalnauka, Vladivostok, pp. 481 - 502.","Leloup, E. (1960) Amphineures du golfe d'Aqaba et de la Peninsule Sinai. Sea Fisheries Research Station, Haifa, Bulletin, 29, 29 - 55, pl. 1.","Leloup, E. (1980) Chitons de la Mer Rouge, du golfe de Suez et de la Mediterranee. Bulletin Institut Royale des Sciences Naturelles de Belgique, 52, 1 - 14, 2 pls.","Risso, A. (1826) Histoire naturelle des principales productions de l'Europe meridionale et principalement de celles des environs de Nice et des Alpes-Maritimes. 4. Mollusques. Levrault, Paris, vii + 439 pp. https: // doi. org / 10.5962 / bhl. title. 58984"]}

Acanthochitona penicillata (Deshayes, 1863) (Fig. 18) Chiton penicillatus Deshayes 1863, p. 41, pl. 6, figs 8, 10. Acanthochites penicillatus; Lamy 1938, p. 88. Chiton (Acanthochiton) penicillatus; Moazzo 1939, p. 218. Achantochiton (sic) (Achantochiton) penicillatus; Selli 1944, p. 6. Acanthochiton penicillatus; Leloup 1952, p.: 9, text-fig. 4, pl. 1, fig. 3, pl. 2, fig. 5; Leloup 1960, p. 32; Leloup 1981, p. 3; Vine 1986, p. 126. Acanthochitona cf. A. penicillata; Ferreira 1983, p. 284, fig. 32. Acanthochitona penicillata; Kaas 1985, p. 339; Kaas 1986, p. 18; Van Belle & Wranik 1991, p. 379, fig. 25; Strack 1993, p. 23, pl. 5, fig. 6; Kaas 1996, p. 372; Schwabe 1997, p. 28, unnumbered figs at p. 27; Drivas & Jay 1998, p. 33, fig. sp. 11; Kaas & Van Belle 1998, p. 141; Dekker & Orlin 2000, p. 7; Slieker 2000, p. 52, fig.37; Abubakr 2004, p. 73; Anseeuw & Terryn 2004, p. 17, figs 56���57; Dell���Angelo et al. 2004, p. 56, pl. 5, figs 10���16; Dekker & Gemert 2008, p. 124; Dinapoli & Janssen 2009, p. 27, pl. 14 a���d; Dell���Angelo et al. 2010a, p. 19, figs 7A���D, 12K; Dell���Angelo et al. 2010b, p. 39, fig. 4F; Sirenko & Schwabe 2011, p. 119; Blatterer 2019, p. 56, pl. 5, fig. 13 a���g. Type material. Unascertained (fide Ferreira 1983). Type locality. ��� Ile de la R��union ��� (21��06��� S, 55��36���E). Material examined. Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study): St. 8: 7 valves (2 head, 4 intermediate and 1 tail) (MZB 60262); St. 9: 3 intermediate valves (MZB 60263). Egypt, Hurghada: St. 12: 18 valves (2 head, 14 intermediate and 2 tail) (BD 219); St. 13: 114 valves (19 head, 82 intermediate and 13 tail), Figs 18 D���I (BD 220; MZB 50556; RGM.1356861); St. 14: 21 valves (2 head and 19 intermediate) (BD 221); St. 14bis: 11 valves (1 head, 7 intermediate and 3 tail), Figs 18 A���C (BD 222; MZB 50555); St. 16: 51 valves (1 head, 40 intermediate and 10 tail) (BD 223); St. 17: 2 valves (1 head and 1 intermediate) (BD 224). Maximum width: 3.3 / 5 / 4.4 mm. Description. Head valve semicircular, posterior margin almost straight, apex hardly developed. Intermediate valve subtrapezoidal, subcarinate in anterior profile, jugal margin straight, side margins rounded, posterior margin slightly concave either side of well developed apex, jugal area triangular, little raised, smooth, except for discrete transversal growth rugae, often showing texture of parallel longitudinal striae. Tail valve almost circular, mucro subcentral, jugal area smooth, raised, antemucronal and postmucronal slopes almost straight, forming angle of about 126��. Tegmentum densely covered with drop-shaped granules, variable in form, arranged in rows radiating from apex, jugal area smooth. Articulamentum well developed, apophyses large, quadrangular, insertion plates well developed, strongly protruding on intermediate valves, expanded and completely surrounding tail valve, except for jugal margin, slit formula 5/1/2. Remarks. The intermediate valves present in our material are keeled, slightly beaked, with a well defined, smooth jugal area, slightly elevated, broader in the front than in the back of the valve, smooth, except for growth lines, and with lateropleural areas bearing rows of roundish/oval granules, radiating from the apex. Although it is difficult to reliably identify this species-group, we attribute our material to A. penicillata, mainly on the basis of the shape of the valves and the smooth jugal area (except for discrete transversal growth rugae). Deshayes��� (1863) original description of Chiton penicillatus is imprecise (Ferreira 1983) and a potential source of confusion. Compared with specimens from Madagascar (Dell���Angelo et al. 2004: pl. 5, figs 10���12) and from the Maldives (Dell���Angelo et al. 2010a: figs 7A���C), the Red Sea valves have less drop-shaped, more rounded pleural granules. However, in his description of specimens from the Red Sea chitons, Strack (1993: 24) noted: ��� tegmentum densely covered with pyriform or drop-shaped granules, variable in form, from almost round (seldom) to elongate pyriform, and in size ���. The Red Sea material at hand has also been compared with other western Indian Ocean species. Many of them have the jugal area more or less longitudinally ribbed: A. mahensis Winckworth, 1927, known from Red Sea, India, Seychelles and Andaman Islands (Anseeuw & Terryn 2004); A. jugotenuis Kaas, 1979 known from Mozambique (Kaas 1979); A. quincunx Leloup, 1981 known from Madagascar (Leloup 1981); A. limbata Kaas, 1986 known from Madagascar (Kaas 1986; Dell���Angelo et al. 2004); A. woodwardi Kaas & Van Belle, 1988 known from Kuwait, Qatar and Socotra Island (Dinapoli & Janssen 2009); Leptoplax curvisetosa (Leloup, 1960) known from Red Sea, Madagascar, Glorieuses Islands and Socotra Island (Strack 1993; Dinapoli & Janssen 2009). Acanthochitona mastalleri Strack 1989, known from Red Sea, Oman and Kenya, is separated from its congeners in having the tegmentum reduced in lateropleural areas (see below). Distribution. Late Pleistocene: Eritrea, Massawa; Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study); Egypt, Hurghada (Selli 1944; this study). Present-day: Indian Ocean: Western Indian Ocean and the Northern Red Sea to Madagascar, Seychelles, R��union and Mauritius; Arabian Sea: Yemen, Socotra Is. (Dinapoli & Janssen 2009; Blatterer 2019)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on pages 430-431, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Deshayes, G. P. (1863) Catalogue des mollusques de l'ile de la Reunion (Bourbon). In: Maillard, L. (Ed.), Notes sur l'Ile de la Reunion, Paris, 1863, pp. 1 - 144. https: // doi. org / 10.5962 / bhl. title. 13126","Lamy, E. (1938) Mission Robert Ph. Dollfus en Egypte. Societe Misr pour les Pecheries S. S. \" Al Sayad \", Resultats Scientifiques. 2 e Partie. VII Mollusca Testacea. Memoires presentees a l'Institut d'Egypte, 37, 1 - 90, 1 pl.","Moazzo, P. G. (1939) Mollusques testaces marins du Canal de Suez. Memoires de l'Institut d'Egypte, 38, 1 - 287.","Selli, R. (1944) I caratteri e le affinita delle malacofaune quaternarie del Mar Rosso (nota preliminare). Giornale di Geologia, 17, 3 - 22.","Leloup, E. (1952) Polyplacophores de l'Ocean Indien et des cotes de l'Indochine francaise. Institut Royale des Sciences Naturelles de Belgique, Memoires, Series 2, 7, 1 - 69, 6 pls.","Leloup, E. (1960) Amphineures du golfe d'Aqaba et de la Peninsule Sinai. Sea Fisheries Research Station, Haifa, Bulletin, 29, 29 - 55, pl. 1.","Leloup, E. (1981) Chitons de Tulear, Reunion, Maurice et Tahiti. Bulletin Institut Royale des Sciences Naturelles de Belgique, 53, 1 - 46, 4 pls.","Vine, P. (1986) Red Sea Invertebrates. IMMEL Publishing, London, 224 pp.","Ferreira, A. J. (1983) Researches on the coast of Somalia. The chiton fauna (Mollusca Polyplacophora). Monitore Zoologico Italiano, 9, 249 - 297. https: // doi. org / 10.1080 / 00269786.1983.11758574","Kaas, P. (1986) Revision of the chitons (Mollusca: Polyplacophora) from the coral-reefs of Tulear, SW Madagascar, and of the Mascarene Islands. Mesogee, 46, 9 - 23.","Van Belle, R. A. & Wranik, W. (1991) Chitons (Mollusca: Polyplacophora) from the Coasts of Yemen and Socotra Island. Fauna of Saudi Arabia, 12, 366 - 381.","Strack, H. L. (1993) The Polyplacophora of the Red Sea. Journal of the Malacological Society of Australia, 14, 1 - 40. https: // doi. org / 10.1080 / 00852988.1993.11923901","Kaas, P. (1996) Chitons (Mollusca: Polyplacophora) from the Seychelles with description of a new species. Zoologische Mededelingen, 70, 367 - 375, figs. 1 - 11.","Schwabe, E. (1997) Beitrag zur Kenntnis einiger Kaferschnecken (Polyplacophora) des Roten Meeres. Club Conchylia Informationen, 29, 25 - 30.","Drivas, J. & Jay, M. (1998) I Chitoni della Reunion. La Conchiglia, 30 (Supplement 289), 32 - 34.","Kaas, P. & Van Belle, R. A. (1998) Catalogue of living chitons (Mollusca, Polyplacophora). Second, revised edition. Backuys Publishers, Leiden, 204 pp.","Dekker, H. & Orlin, Z. (2000) Check-list of Red Sea Mollusca. Spirula, 47 (Supplement), 1 - 46.","Slieker, F. J. A. (2000) Chitons of the world. An illustrated synopsis of recent Polyplacophora. L'Informatore Piceno Ed., Ancona, 154 pp.","Abubakr, M. M. (2004) The Republic of Yemen Marine Biotic Ecosystem (Resources-Habitats and Species). Ministry of Water and Environment, Environment Protection Authority, Aden, 128 pp.","Anseeuw, B. & Terryn, Y. (2004) Intertidal chitons (Mollusca: Polyplacophora) from the coast of Jordan, Red Sea, with the description of a new species of Parachiton Thiele, 1909. Bollettino Malacologico, Supplement 5, 1 - 24.","Dell'Angelo, B., Bonfitto, A., Sabelli, B. & Taviani, M. (2004) Chitons (Mollusca, Polyplacophora) from bioclastic sands of the Ifaty-Tulear back reefs (Madagascar, Western Indian Ocean). Bollettino Malacologico, Supplment 5, 45 - 62.","Dekker, H. & Gemert, L. J. van (2008) A new list with corrections to the shells pictured in \" Red Sea Shells \" (1984) by Doreen Sharabati. De Kreukel, 44, 123 - 136.","Dinapoli, A. & Janssen, R. (2009) Polyplacophora (Mollusca) of the Socotra Arcipelago - Systematics and Biogeography. Fauna of Arabia, 24, 1 - 46.","Dell'Angelo, B., Gori, S., Baschieri, L. & Bonfitto, A. (2010 a) Chitons (Mollusca, Polyplacophora) from the Maldive islands. Zootaxa, 2673 (1), 1 - 38. https: // doi. org / 10.11646 / zootaxa. 2673.1.1","Dell'Angelo, B., Sabelli, B., Taviani, M. & Bonfitto, A. (2010 b) New data on the Polyplacophora of Madagascar (Western Indian Ocean) (Mollusca: Polyplacophora). Archiv fur Molluskenkunde, 139, 35 - 43. https: // doi. org / 10.1127 / arch. moll / 1869 - 0963 / 139 / 035 - 043","Sirenko, B. I. & Schwabe, E. (2011) Description of a minute new chiton (Mollusca, Polyplacophora) from Sri Lanka. Ruthenica, 21, 113 - 121.","Blatterer, H. (2019) Mollusca of the Dahab region. Oberosterreichisches Landesmuseum, Linz, Austria, 480 pp.","Winckworth, R. (1927) New species of chitons from Aden and South India. Proceedings of the Malacological Society of London, 17, 206 - 208, pls. 28 - 29.","Kaas, P. (1979) The Chitons (Mollusca: Polyplacophora) of Mozambique. Annals of the Natal Museum, 23, 855 - 879.","Kaas, P. & Van Belle, R. A. (1988) Chitons (Mollusca: Polyplacophora) from the coasts of Oman and the Arabian Gulf. American Malacological Bulletin, 6, 115 - 130.","Strack, H. L. (1989) Description of a new Acanthochitona species (Polyplacophora) from the Red Sea. Journal of Conchology, 33, 169 - 172, pls. 19 - 20."]}

Acanthochitona interglacialis n. sp. (Fig. 20) Type material. Holotype: MZB 50560, an intermediate valve, width 1.6 mm (Figs 20 A–C). Type locality. Saudi Arabia, Gulf of Aqaba, Ash Shaykh Humayd: St. 8. Type stage. Late Pleistocene, last interglacial MIS5e. Etymology. The name refers to the stratigraphic occurrence of the available material (interglacial deposits). Diagnosis. Intermediate valve pentagonal, elevated, rounded in anterior profile, posterior margin slightly concave either side of strongly protruding apex. Tegmentum sculptured with elongated, flattened pustules of variable size. Articulamentum with apophyses projecting forward, insertion plate short with one slit on each side. Description. Intermediate valve pentagonal, elevated (H/W = 0.55), rounded in anterior profile, anterior margin strongly concave in jugal part, posterior margin slightly concave on both sides of strongly protruding apex. Tegmentum sculptured with elongated, widely-spaced, irregularly arranged, flattened pustules, of variable size, up to 100 µm in length, with up to 13 microaesthetes irregularly disposed. Articulamentum with apophyses projecting forward, insertion plate short with short, narrow slits, one on each side. Remarks. A single intermediate valve is present in the studied material that superficially resembles an intermediate valve of the genus Acanthochitona, but without a well developed jugal area. The jugal area is in continuity with the pleural areas and not separate, and it has the same type of sculpture formed by large granules, albeit more irregular and less evident. The elevation of the valve is an uncommon character in Acanthochitona. We therefore describe this unique intermediate valve as a new species. The attribution to the genus Acanthochitona is tentative, based on the great similarity of this valve with intermediate valves pertaining to Acanthochitona. Other living species of Acanthochitona without a well defined jugal area are known, i.e. Acanthochitona sp. (Sirenko 2012: 98, fig. 33) and A. lanae Sirenko & Saito, 2017 (Sirenko & Saito 2017: fig. 30), both from Vietnam, but this could be the first report (B. Sirenko, pers. comm.) of a fossil species of Acanthochitona with this feature. Distribution. Late Pleistocene: Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study).

Lucilina confusa n. sp. (Fig. 11, 12) Type material. The type material is reported in Tab. 2. Other material. Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd): St. 8: 12 valves (2 head and 10 intermediate) (MZB 60258); St. 9: 20 valves (3 head and 17 intermediate) (MZB 60259). Egypt, Hurghada: St. 13: 33 valves (2 head, 24 intermediate and 7 tail), Figs 11 M���N (BD 205; MZB 50543); St. 14: 33 valves (5 head, 21 intermediate and 7 tail) (BD 206; RGM.1356858); St. 14bis: 18 valves (1 head, 11 intermediate and 6 tail) (BD 207); St. 15: 3 valves (1 head, 1 intermediate and 1 tail) (BD 208); St. 16: 8 valves (2 head, 3 intermediate and 3 tail (BD 209). Recent material examined. Zabargad island (13/30): 42 valves (5 head, 28 intermediate and 9 tail) (Figs 12 A- I) (MZB 50544). Sudan, Sha���ab Rum Reef (P078): 14 valves (2 head, 10 intermediate and 2 tail) (BD 210). Egypt, Gulf of Aqaba (Blue Hole) (P447A): 3 intermediate valves (BD 211). Maximum width: 4.4 / 7.5 / 7.2 mm. Type locality. Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study): St. 9. Type stage. Late Pleistocene, last interglacial (MIS5e). Etymology. The name indicates the fact that a rather common species in this region has been for long confused with morphologically close taxa. Diagnosis. Head valve semicircular; intermediate valve rectangular, moderately elevated, anterior profile subcarinated, posterior margin slightly concave at both sides of prominent apex, lateral areas not raised; tail valve semicircular, mucro small, raised, in posterior position, antemucronal slope almost straight, postmucronal slope steep, straight to weakly convex. Tegmentum sculptured with irregular radial striae of roundish granules on head valve, lateral areas of intermediate valves and postmucronal area of tail valve; central area of intermediate valves and postmucronal area of tail valve sculptured with irregular and well-separated longitudinal striae of rounded to oval granules.Articulamentum white, apophyses well developed, rounded, jugal sinus wide, slit formula 8/1/9, teeth relatively long, finely grooved on upper side, denticulated on outer edge. Description. Head valve (based on Paratype 1, Fig. 11F) semicircular, front slope slightly convex, posterior margin widely V-shaped, tegmentum sculptured with ca 34 irregularly radial striae of roundish, elevated granules (diameter ca 60���75 ��m), up to 10���12 granules per stria; striae do not start from apex, but from small, smooth circular area around apex, ocelli minute (diameter ca 40 ��m), scarcely visible, aligned in interstices of radial striae of granules. Intermediate valve (based on Paratype 2, Fig. 11J) rectangular, L/W = 0.38, anterior margin sinuose, slightly concave in wide central part, convex at pleurae, moderately elevated (H/W = 0.36), anterior profile subcarinated, side margins rounded, posterior margin slightly concave at both sides of prominent apex, lateral areas not raised, sculptured like head valve with 7���8 irregular radial striae of granules, ocelli numerous in anterior third of valve, pleural areas with similar granules arranged in ca 20���22 longitudinal, irregular and well-separated striae on each side, slightly oblique near jugum and in opposite direction towards side margins, granules more irregular, rounded to oval, diameter up to 100 ��m, jugal area smooth, triangular, irregularly defined. Tail valve (based on Holotype, Fig. 11A) semicircular, length ca half width (L/W = 0.51), front margin almost straight, mucro small, raised, in posterior position, antemucronal slope almost straight, postmucronal slope steep, straight to weakly convex, antemucronal area sculptured with ca 16 longitudinal striae of roundish-oval, more elevated granules on each side, with granule diameter up to 70 ��m, jugal area smooth, irregularly defined, postmucronal area with sculpture like head valve with ca 40 radial striae of granules, ocelli randomly dispersed in postmucronal area. Articulamentum white, apophyses well developed, rounded, jugal sinus wide, slit formula 8/1/9, slit rays faintly visible in head and intermediate valves, teeth relatively long, those of tail valve slightly forwardly directed, all teeth finely grooved on upper side, denticulated on outer edge, eaves narrow, solid. Variability. The species show a great variability in the sculpture of the valves as well as other characters. Head valve: the radial striae of roundish, elevated granules, can be more irregularly defined, large and widely spaced as in the figured valve from Egypt, Hurghada (Fig. 11M, width 3.3 mm, ca 25 radial striae, diameter up to 90���100 ��m, ca 6���7 granules for each radial stria). The number of more or less irregular radial striae of granules ranges between 25 and 35, and the number of slits in the articulamentum ranges between six and eight. Intermediate valves: the number and the orientation of longitudinal striae of granules in the pleural areas is variable, as can be seen in the figured valve from Egypt, Hurghada (Fig. 11N, width 5 mm, ca 16 longitudinal striae on each side, striae more regular and parallel). Also the radial striae of granules in lateral areas are generally irregularly defined, in some valves are more numerous and well defined (as in Fig. 11N). L/W = 0.36���0.41; H/W = 0.33���0.37. The jugal area is usually triangular and smooth, only in very few valves the striae of granules cover partially the jugal area, leaving a very narrow, wedge shaped, smooth band. The ocelli are scarcely visible, not black, and can radially cover up to half of the lateral area. Tail valve: the sculpture shows the same variability as in intermediate valves, also for these valves the striae of granules can partially cover the jugal area (Fig. 11O).The number of slits ranges between 9 and 12. Remarks. Several species of Lucilina are known from the Indian Ocean (Kaas et al. 2006), but only two from the Red Sea, L. sueziensis (Reeve, 1847) and L. perligera Thiele, 1909 (see above) (Anseeuw & Terryn 2004). Lucilina perligera is similar to Lucilina confusa n. sp., from which it differs mainly by the tegmentum sculptured with large, elevated, roundish, clearly separated, quincuncially arranged, granules in the head valve, lateral areas of intermediate valves, and postmucronal area of the tail valve, while in pleural and antemucronal areas the granules are vaguely arranged in curved, forwardly converging rows, also extending over the jugum. The granules are larger, and wider spaced than those of L. confusa n. sp. Two other Lucilina species are present in the studied material and have a similar sculpture with longitudinal and radial striae of granules: Lucilina aegyptiaca n. sp. and Lucilina colantonii n. sp. (see below). The main characters of the intermediate valves of these species and of L. sueziensis (based on the description of Kaas et al. 2006 and on personal observations) are presented in Tab. 3. Numerous valves of Lucilina confusa n. sp. are present in the extant material from the Red Sea expeditions (currently under study, unpublished), mixed in samples initially labeled as L. sueziensis and L. perligera. Some of these valves are illustrated for comparison (Figs 12 A���I). No significant differences were found between the fossil and extant valves described in this study. The figured head valve (Figs 12 A���C) has ca 35 irregular radial striae of granules, with striae of ocelli in the interstices (diameter ca 40 ��m), eight slits, and falls within the range of variability indicated above. Similarly, the intermediate valve (Figs 12 D���F) and the figured tail valve (Figs 12 G���I) fall within the range of variability indicated above. The longitudinal striae of granules in intermediate valves partially extends over the jugal area (Fig. 12D), only a small part near the anterior margin is smooth. Distribution. Late Pleistocene: Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study); Egypt (Hurghada: this study). Present-day: Red Sea: Zabargad island; Sudan (Shab Runi Reef); Egypt, Gulf of Aqaba (Blue Hole)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on pages 419-422, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Kaas, P., Van Belle, R. A. & Strack, H. L. (2006) Monograph of Living Chitons (Mollusca: Polyplacophora). Volume 6. Suborder Ischnochitonina (concluded): Schizochitonidae; Chitonidae. Additions to Volumes 1 - 5. E. J. Brill, Leiden-Boston, 463 pp.","Reeve, L. (1847) Conchologia iconica, or illustrations of the shells of molluscous animals. Monograph of the genus Chiton. Vol. 4. Reeve, Brothers, London, 64 pp., 28 pls. [pp. 21 - 84]","Thiele, J. (1909) Revision des Systems der Chitonen. Zoologica, 22, 1 - 132, pls. 1 - 10. https: // doi. org / 10.5962 / bhl. title. 11245","Anseeuw, B. & Terryn, Y. (2004) Intertidal chitons (Mollusca: Polyplacophora) from the coast of Jordan, Red Sea, with the description of a new species of Parachiton Thiele, 1909. Bollettino Malacologico, Supplement 5, 1 - 24."]}

Genus Choneplax Dall, 1882 Type species. Chiton strigatus Sowerby, 1840 (= Chitonellus latus Guilding, 1829), by original designation. Remarks. The genus Choneplax Dall, 1882 includes four Recent species (Sirenko 2003): C. lata (Guilding, 1829) from the Caribbean, C. hastata (Sowerby, 1840), habitat unknown (fide Sirenko 2003), C. indica from the W. Indian Ocean, and C. littlerorum Sirenko, 2003 from American Samoa. This is the first fossil record for the genus. Distribution. Indian and Pacific (American Samoa) Oceans, and West Atlantic, Pleistocene to present-day.

Cryptoplax sykesi Thiele, 1909 (Fig. 23) Cryptoplax sp. cf. C. striatus; Sykes 1900, p. 164, figs 2���5. Cryptoplax striatus; Sykes 1907, p. 33. Cryptoplax sykesi Thiele 1909, p. 53, pl.6, figs 83���86 (nom. nov. x Cryptoplax striatus); Ferreira 1983, p. 287, fig. 33; Strack 1993, p. 27, pl. 5, fig. 9; Kilias 1995, p. 169; Anseeuw & Terryn 2004, p. 16, fig. 55; Dinapoli & Janssen 2009, p. 36, pl. 19a���b; Blatterer 2019, p. 56, pl. 6, fig. 17a-f. Criptoplax (sic) striatus; Selli 1944, p. 6. Cryptoplax erythraeus Selli 1973, p. 260, pl. 11, figs 8���9. Cryptoplax enigmaticus Leloup 1980, p. 7, pl.1, figs 1���2; pl.2, fig.1; Ferreira 1983, p. 289 (fide Ferreira 1983). Non Cryptoplax sykesi; Leloup 1940, p. 9, fig. 3, pl. 2, figs 1���2; Kaas 1986, p. 21, figs 73���81; Dell���Angelo et al. 2004, p. 60, pl. 6, figs 14���15; Dell���Angelo et al. 2010a, p. 32, figs 11M���O. ? (reported as Cryptoplax sykesi without description or figures); Leloup 1952, p. 53; Kaas 1985, p. 333; Kaas 1996, p. 373; Slieker 2000, p. 50, pl.13, fig.31; Ghobashy & Kotb 2002, p. 6. ? (reported as Cryptoplax striatus without description or figures); Leloup 1981, p. 21. Type material. ZMHU, ZMB Moll 102.074 (Fig. 23B). Type locality. Red Sea, ���Gimsah-Bay��� (Kilias 1995). Material examined. Eritrea, Massawa North, Abd-el-Cader (St. 20): 2 tail valves, described and illustrated by Selli (1973: pl. 11, figs 8���9), deposited at MGGC, with the indication ���Massaua E��� on the label (Fig. 23A). Eritrea, Massawa South (St. 21): 2 valves (1 intermediate and 1 tail), Figs 23 C���D (MZB 00930). Jordan, Aqaba, Yamanie (St. 1): 3 intermediate valves (MZB 60269). Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd): St. 8: 4 valves (3 intermediate and 1 tail), Figs 23 H���I (MZB 50566); St. 9: 6 valves (5 intermediate and 1 tail) (MZB 60270). Egypt (Hurghada): St. 13: 16 valves (10 intermediate and 6 tail), Figs 23 E���G, 23J���O (BD 231; MZB 50565; RGM.1356863). Maximum width: -/3/ 1.2 mm. Description. Intermediate valves elliptical in shape, more or less elongated, jugal area narrow, smooth, almost rectangular, only slightly reduced near apex, growth lines clearly visible, latero-pleural areas sculptured with 5���6 longitudinal striae of irregular roundish granules starting from apex running parallel to jugal area. Tail valve with mucro situated terminally, not elevated, inconspicuous, jugal area narrow and smooth, almost rectangular, growth lines clearly visible, antemucronal area sculptured like intermediate valves, postmucronal area lacking. Tegmentum surface completely granulated, except for smooth jugal area, granules more irregular, often coalescing into longitudinal riblets, on each side of jugum. Articulamentum strongly developed, intermediate and tail valves with elongate apophyses, slit formula -/0/0. Remarks. The identification of Cryptoplax sykesi has presented some problems in past years. Specimens of Cryptoplax from east Africa were identified at first by Sykes (1900, 1907) as C. striata (Lamarck, 1819), a species originally described from Australian waters. Thiele (1909), based on a specimen from the Red Sea, pointed out specific differences in the shape of the tail valve, the jugal area and girdle elements, and proposed the name C. sykesi for his and Sykes��� (1907) specimens. Thiele (1909) described the sculpture of the latero-pleural areas as clearly granulose (��� The jugal field is smooth, the lateral fields with granules, which are more or less orientated in longitudinal lines ���), even if this is not evident in his figures (Thiele 1909: figs 83���85, the sculpture seems more as longitudinal riblets than granulose), however the granulose sculpture is confirmed by the figure of the fourth valve of the lectotype deposited at ZMHU (Fig. 23B). Subsequently, some authors have described and illustrated specimens identified as Cryptoplax sykesi with a sculpture of the latero-pleural areas characterised by longitudinal riblets, broken up into granules only near the apex area, e.g. Leloup (1940: 9, fig. 3, pl. 2, figs 1���2) for specimens from Vietnam; Kaas (1986: 21, figs 73���81) and Dell���Angelo et al. (2004: 60, pl. 6, figs 14���15) for specimens from Madagascar; Dell���Angelo et al. (2010b: 32, figs 11M���O) for specimens from the Maldive Islands. These specimens might represent a distinct species (H. Saito, pers. com.) for which the correct identification needs further study, which is beyond the scope of this work. The two valves from Massawa reported by Selli (1973) as Cryptoplax sykesi clearly show a granulose sculpture. Selli described the two valves as intermediate [but some lines below: ��� Quasi certamente rappresentano le valve 7 e 8 ��� (Almost certainly they represent the valves vii and viii)]. On further examination, they are two tail valves, as can be seen by the different structure of the articulamentum (e.g. see the lateral view of an intermediate and tail valves of Cryptoplax weinlandi ��ulc, 1934 from the Miocene of North Italy in Dell���Angelo et al. 2016: pl. 7, figs 20, 23, respectively). Selli (1973) thought that his valves with a granulose sculpture could be different from those of Cryptoplax sykesi with longitudinal riblets, and therefore proposed (in note) the name Cryptoplax erythraeus n. sp. for his valves. Since the attribution of Selli���s (1973) material to Cryptoplax sykesi is correct, the taxon Cryptoplax erythraeus must be considered a subjective synonym. Selli���s material comes from the site of ���Massawa Nord��� (Abd-el-Cader peninsula, about. 2 km North of Massawa), and is stored at MGGC, but with the museum label states ���Massaua E��� (Fig. 23D). The available material consists of two valves in poor conditions of preservation (intermediate and tail) from the Agip expedition (ex Selli 1973) from ���Massawa South��� (near the lighthouse in the eastern part of the islet on which stands the city of Massawa). In the study material at hand, the striae of granules are variable, with the granules more regular in some valves (Figs 23H, J) or coalescent in some tracts, giving the impression of riblets (Fig. 23 E���G). This sculpture is similar to that of Cryptoplax enigmaticus Leloup, 1980, a species described from the Red Sea (Israel, Eilat) (see Leloup 1980: pl. 1, fig. 1). This species was discussed by Ferreira (1983: 289), who considered the specimens to be juvenile specimens of C. sykesi. The valves of Cryptoplax sykesi resemble those of Choneplax indica in many respects, but complete living specimens of both species are easily separable. However, it is more difficult to separate single valves (see above, under the discussion of Choneplax indica). Distribution. Late Pleistocene: Eritrea, Massawa North (Abd-el-Cader), and Massawa South; Jordan, Aqaba (Yamanie); Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study); Egypt, (Hurghada) (Selli 1944, 1973; this study). Present-day: Western Indian Ocean from the northern Red Sea to South Africa, Yemen and Socotra Island (Strack 1993; Dinapoli & Janssen 2009; Blatterer 2019)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on pages 437-439, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Thiele, J. (1909) Revision des Systems der Chitonen. Zoologica, 22, 1 - 132, pls. 1 - 10. https: // doi. org / 10.5962 / bhl. title. 11245","Sykes, E. R. (1900) Malacological Notes. 2. On the occurrence of Cryptoplax in South Africa. The Journal of Malacology, 7, 164 - 165.","Sykes, E. R. (1907) Reports on the marine biology of the Sudanese Red Sea. 5. On the Polyplacophora or chitons. Journal of the Linnean Society of London, 31, 31 - 34. https: // doi. org / 10.1111 / j. 1096 - 3642.1907. tb 00450. x","Ferreira, A. J. (1983) Researches on the coast of Somalia. The chiton fauna (Mollusca Polyplacophora). Monitore Zoologico Italiano, 9, 249 - 297. https: // doi. org / 10.1080 / 00269786.1983.11758574","Strack, H. L. (1993) The Polyplacophora of the Red Sea. Journal of the Malacological Society of Australia, 14, 1 - 40. https: // doi. org / 10.1080 / 00852988.1993.11923901","Kilias, R. (1995) Polyplacophora-Typen und - Typoide (Mollusca) im Zoologischen Museum in Berlin. Mitteilungen aus dem Zoologischen Museum in Berlin, 71, 155 - 170. https: // doi. org / 10.1002 / mmnz. 19950710118","Anseeuw, B. & Terryn, Y. (2004) Intertidal chitons (Mollusca: Polyplacophora) from the coast of Jordan, Red Sea, with the description of a new species of Parachiton Thiele, 1909. Bollettino Malacologico, Supplement 5, 1 - 24.","Dinapoli, A. & Janssen, R. (2009) Polyplacophora (Mollusca) of the Socotra Arcipelago - Systematics and Biogeography. Fauna of Arabia, 24, 1 - 46.","Blatterer, H. (2019) Mollusca of the Dahab region. Oberosterreichisches Landesmuseum, Linz, Austria, 480 pp.","Selli, R. (1944) I caratteri e le affinita delle malacofaune quaternarie del Mar Rosso (nota preliminare). Giornale di Geologia, 17, 3 - 22.","Selli, R. (1973) Molluschi quaternari di Massaua e di Gibuti. In: Accademia Nazionale dei Lincei. Missione Geologica dell'AGIP nella Dancalia meridionale e sugli Altipiani Ararini 1936 - 1938. Vol. IV. Parte Seconda. Documentazione Paleontologica, Roma, pp. 153 - 444, 30 pls.","Leloup, E. (1980) Chitons de la Mer Rouge, du golfe de Suez et de la Mediterranee. Bulletin Institut Royale des Sciences Naturelles de Belgique, 52, 1 - 14, 2 pls.","Leloup, E. (1940) Les Chitons du genre Cryptoplax Blainville, 1818. Bulletin de Musee royal d'Histoire naturelle de Belgique, 16 (33), 1 - 32, pls. 1 - 3.","Kaas, P. (1986) Revision of the chitons (Mollusca: Polyplacophora) from the coral-reefs of Tulear, SW Madagascar, and of the Mascarene Islands. Mesogee, 46, 9 - 23.","Dell'Angelo, B., Bonfitto, A., Sabelli, B. & Taviani, M. (2004) Chitons (Mollusca, Polyplacophora) from bioclastic sands of the Ifaty-Tulear back reefs (Madagascar, Western Indian Ocean). Bollettino Malacologico, Supplment 5, 45 - 62.","Dell'Angelo, B., Gori, S., Baschieri, L. & Bonfitto, A. (2010 a) Chitons (Mollusca, Polyplacophora) from the Maldive islands. Zootaxa, 2673 (1), 1 - 38. https: // doi. org / 10.11646 / zootaxa. 2673.1.1","Leloup, E. (1952) Polyplacophores de l'Ocean Indien et des cotes de l'Indochine francaise. Institut Royale des Sciences Naturelles de Belgique, Memoires, Series 2, 7, 1 - 69, 6 pls.","Kaas, P. (1996) Chitons (Mollusca: Polyplacophora) from the Seychelles with description of a new species. Zoologische Mededelingen, 70, 367 - 375, figs. 1 - 11.","Slieker, F. J. A. (2000) Chitons of the world. An illustrated synopsis of recent Polyplacophora. L'Informatore Piceno Ed., Ancona, 154 pp.","Ghobashy, A. F. A. & Kotb, M. M. A. (2002) Review of the biological aspects of the Red Sea. Biologia Marina Mediterranea, 8 (2001), 1 - 14.","Leloup, E. (1981) Chitons de Tulear, Reunion, Maurice et Tahiti. Bulletin Institut Royale des Sciences Naturelles de Belgique, 53, 1 - 46, 4 pls.","Lamarck, J. B. P. A. de M. (1819) Histoire naturelle des animaux sans vertebres, presentant des characters generaux et particuliers de ces animaux, leur distribution, leurs classes, leurs familles, leurs genres, ret la citation des principales especes qui s'y rapportent, precedee dune introduction offrant la determination des caracteres essentiels de l'animal, sa distinction du vegetal et des autres corps naturels; enfin, l'exposition des principes fondamentaux de la zoologie. 6 (1). J. B. Bailliere, Paris, 343 pp.","Dell'Angelo, B., Sabelli, B., Taviani, M. & Bonfitto, A. (2010 b) New data on the Polyplacophora of Madagascar (Western Indian Ocean) (Mollusca: Polyplacophora). Archiv fur Molluskenkunde, 139, 35 - 43. https: // doi. org / 10.1127 / arch. moll / 1869 - 0963 / 139 / 035 - 043","Sulc, J. (1934) Studien uber die fossilen Chitonen. I. Die fossilen Chitonen im Neogen des Wiener Beckens und der angrenzenden Gebiete. Annalen des Naturhistorischen Museums in Wien, 47, 1 - 31, pls. 1 - 2.","Dell'Angelo, B., Giuntelli, P., Sosso, M. & Zunino, M. (2016) Polyplacophora from the Miocene of North Italy. Part 2: Callochitonidae, Chitonidae, Lepidochitonidae, Acanthochitonidae and Cryptoplacidae. Rivista Italiana di Paleontologia e Stratigrafia, 122, 23 - 54."]}

Lucilina aqabaensis n. sp. (Fig. 13) Type material. Holotype: MZB 50545, a tail valve, St. 9, width 6.5 mm (Figs 13 A���F). Type locality. Gulf of Aqaba, Saudi Arabia (Ash Shaykh Humayd: this study): St. 9. Type stage. Late Pleistocene, last interglacial MIS5e. Etymology. The name refers to the Gulf of Aqaba, source of the material here described. Diagnosis. Tail valve semioval, mucro posterior, obtuse, antemucronal slope slightly convex, postmucronal slope perpendicular. Tegmentum finely granulose, antemucronal and postmucronal areas with concentric growth lines, characterised by the presence of groups of fused granules, irregularly arranged in concentric striae. Articulamentum white, apophyses well developed, jugal sinus wide, 10 slits, teeth slightly forwardly directed, finely grooved on upper side. Description. Tail valve semioval, length less than half width (L/W = 0.42), front margin straight, hind margin angularly rounded, mucro posterior, obtuse, antemucronal slope slightly convex, postmucronal slope perpendicular. Tegmentum finely granulose, roundish granules irregularly dispersed, extending over entire surface of valve, both antemucronal and postmucronal areas with concentric growth lines, characterised by the presence of groups of fused granules, more frequent and larger in postmucronal area along hind margin, giving the impression of being irregularly arranged in concentric striae. Roundish granules small and close-set, diameter ca 48���60 ��m, with 1 large central macroaesthete and up to 10 microaesthetes along margin. Articulamentum white, apophyses well developed, jugal sinus wide, provided with a short plate, 10 slits, slit rays not indicated, teeth relatively long, slightly forwardly directed, all teeth finely grooved on upper side, denticulated on outer edge, eaves narrow, solid. Remarks. We assign this unique tail valve to the genus Lucilina based on the presence of having grooved teeth on the articulamentum (and not a callus as in the genus Onithochiton Gray, 1847), and having the mucro subterminal (and not subcentral as in the genus Tonicia Gray, 1847) (Kaas et al. 2006: 294). We did not observe the presence of ocelli in the postmucronal area. The characters of this single tail valve are so distinctive that they warrant description as a new species. The peculiar granulose sculpture of this species is different from that of other Lucilina species known from the Red Sea (including those described herein), and Indian Ocean (Kaas et al. 2006). Distribution. Late Pleistocene: Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on page 423, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Gray, J. E. (1847) A list of the genera of Recent Mollusca, their synonyms and types. Proceedings of the Zoological Society of London, 15, 129 - 206. https: // doi. org / 10.1111 / j. 1469 - 7998.1847. tb 00164. x","Kaas, P., Van Belle, R. A. & Strack, H. L. (2006) Monograph of Living Chitons (Mollusca: Polyplacophora). Volume 6. Suborder Ischnochitonina (concluded): Schizochitonidae; Chitonidae. Additions to Volumes 1 - 5. E. J. Brill, Leiden-Boston, 463 pp."]}

��� Onithochiton ��� vandingeneni n. sp. (Fig. 16) Type material. Holotype MZB 50552, 1 intermediate valve, width 1.5 mm, Figs 16 A���E. Type locality. Gulf of Aqaba, Saudi Arabia (Ash Shaykh Humayd: St. 8). Recent material examined. Zabargad Island (13/30): 1 intermediate valve, width 3.6 mm (Figs 16 F���I) (MZB 50553). Type stage. Late Pleistocene, last interglacial MIS5e. Etymology. In honour of Frank Van Dingenen who contributed generously a substantial part of the material here studied. Diagnosis. Intermediate valve rectangular, moderately elevated, posterior margin beaked, lateral areas weakly raised, with a diagonal line just outlined. Tegmentum smooth to naked eye, concentric growth lines vaguely indicat- ed on lateral areas, 3���4 ocelli on each side present on anterior half of lateral areas. Articulamentum with apophyses semicircular, one slit. Description. Intermediate valve rectangular, moderately elevated (H/W = 0.30), rounded in anterior profile, anterior margin slightly concave, lateral margins rounded, posterior margin beaked, straight to concave at both sides of protruding apex, lateral areas weakly raised, with a diagonal line just outlined. Tegmentum microscopically punctate, smooth to naked eye, concentric growth lines vaguely indicated on lateral areas, extending (mostly eroded) over central area, 3���4 ocelli on either side (diameter ca 24 ��m) present on anterior half of lateral areas. Articulamentum with apophyses semicircular, one slit. Remarks. This unique intermediate valve could be attributed to any one of the three genera included in the subfamily Toniciinae Pilsbry, 1893 (Tonicia Gray, 1847, Lucilina Dall, 1882, and Onithochiton Gray, 1847), as generic attribution within the subfamily is mainly based on the characters of the tail valve (Kaas et al. 2006). Unfortunately, tail valves are not present in the studied material. Thus far, the genus Tonicia has not been reported from the Red Sea (see above), and we provisionally attribute our material to Onithochiton, pending further material. Specific attribution is also problematic. The single valve is quite different from that of the other species discussed herein under Lucilina (see above). It is also quite different from the only species of Onithochiton living in the Red Sea, O. erythraeus Thiele, 1909 (known also from Yemen, Socotra Isl., Oman and the Arabian Gulf), characterised by the central area sculptured with numerous fine, longitudinal, forwardly converging grooves (Kaas et al. 2006). Two further species of Onithochiton are known from the Indian Ocean, O. literatus (Krauss, 1848) (from Mozambique and S. Africa] and O. maillardi (Deshayes, 1863) (from southern Madagascar, and Mascarene, Rodriguez and Seychelles islands) (Kaas et al. 2006), both characterised by a well defined tegmentum sculpture (not smooth as in ��� O.��� vandingeneni n. sp.). A single intermediate valve very similar to ��� Onithochiton ��� vandingeneni n. sp. is present in the Recent material in study from the Red Sea (Zabargad Island, st. 09/06) (Fig. 16 F���I). This valve is larger (width 3.6 mm, more than double the studied fossil valve). However, we consider that the differences found (the presence of rugosities in the lateral areas, and the greater number of ocelli of largest size, up to 55 ��m vs 24 ��m in the studied fossil valve) are likely to fall within the intraspecific variability of ���O.��� vandingeneni n. sp. Distribution. Late Pleistocene: Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study). Present-day: Red Sea, Zabargad island., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on pages 427-428, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Pilsbry, H. A. (1892 - 1894) Monograph of Polyplacophora. In: Tryon, G. W., Manual of Conchology. Vol. 15 & 16. Academy of Natural Sciences, Philadelphia, pp. 1 - 128, pls. 1 - 30 (1892) + pp. i-xxxiv, 129 - 350, pls. 31 - 68 (1893) & pp. 1 - 64, pls. 1 - 10 (1893) + pp. 65 - 133, pls. 11 - 17 (1894).","Gray, J. E. (1847) A list of the genera of Recent Mollusca, their synonyms and types. Proceedings of the Zoological Society of London, 15, 129 - 206. https: // doi. org / 10.1111 / j. 1469 - 7998.1847. tb 00164. x","Dall, W. H. (1882) On the genera of chitons. Proceedings of the United States National Museum, 4, 279 - 291. https: // doi. org / 10.5479 / si. 00963801.4 - 228.279","Kaas, P., Van Belle, R. A. & Strack, H. L. (2006) Monograph of Living Chitons (Mollusca: Polyplacophora). Volume 6. Suborder Ischnochitonina (concluded): Schizochitonidae; Chitonidae. Additions to Volumes 1 - 5. E. J. Brill, Leiden-Boston, 463 pp.","Thiele, J. (1909) Revision des Systems der Chitonen. Zoologica, 22, 1 - 132, pls. 1 - 10. https: // doi. org / 10.5962 / bhl. title. 11245","Krauss, F. (1848) Die Sudafrikanischen Molluschen. Ein Beitrag zur kenntnis der Mollusken des Kap- und Natallandes und zur geographischen Verbreitung derselben. Stuttgart, 140 pp., 4 pls. https: // doi. org / 10.5962 / bhl. title. 13936","Deshayes, G. P. (1863) Catalogue des mollusques de l'ile de la Reunion (Bourbon). In: Maillard, L. (Ed.), Notes sur l'Ile de la Reunion, Paris, 1863, pp. 1 - 144. https: // doi. org / 10.5962 / bhl. title. 13126"]}

Genus Lucilina Dall, 1882 Type species. Chiton confossus Gould, 1846 (= Chiton lamellosus Quoy & Gaimard, 1835), by subsequent designation (Pilsbry 1893). Remarks. Following the suggestions of some authors (e.g., Strack 2003; Schwabe 2004, 2006; Schwabe et al. 2008; Schwabe & Pittman 2014), the genus Lucilina is here used at full genus level, and not as a subgenus of Tonicia Gray, 1847. The species of Tonicia are geographically restricted to the South Eastern Pacific region of Latin America with a single species in the Caribbean, while members of Lucilina are widespread throughout the tropical Indo-Pacific. Lucilina is well represented in the Indian Ocean by six species, L. sueziensis (Reeve, 1847), L. perligera Thiele, 1909, L. pectinoides (Sykes, 1903), L. ceylonica (Leloup, 1936), L. carnosa (Kaas, 1979) and L. indica (Leloup, 1981), of which only the first two are known from the Red Sea. Distribution. Widespread in the Indian Ocean, the Indo-Pacific, Australia, the Central Pacific Ocean and Japan. The fossil record extends back to the middle Oligocene of France, Aquitaine Basin (Dell’Angelo et al. 2018a), the Neogene of west Pacific islands (Ladd 1966; Schwabe et al. 2008) and the Pleistocene of the Red Sea (Issel 1869).

Acanthopleura vaillantii de Rochebrune, 1882 (Fig. 17) Chiton (Tonicia) sueziensis, non Reeve; Issel 1869, p. 235 (pars). Acantopleura (sic) vaillantii de Rochebrune 1882, p. 192. Acanthopleura gemmata; Ferreira 1983, p. 278, fig. 30. Acanthopleura haddoni; Vine 1986, p. 126, unnumbered figs p. 125, 126. Acanthopleura vaillantii; Ferreira 1986, p. 231, fig. 17; Kaas & Van Belle 1988, p. 123; Strack 1993, p.: 17, pl. 4, figs 3���4; Bosch et al. 1995, p. 190, fig. sp. 885; Dekker & Orlin 2000, p. 7; Slieker 2000, p. 50, fig. 24; Brooker 2003, p. 44, 153, 214, 486, figs 5.8, 6.5; Abubakr 2004, p. 73; Anseeuw & Terryn 2004, p. 14, figs 46���47; Kaas et al. 2006, p. 268, fig. 109, map 45; Dekker & Gemert 2008, p. 124; Dinapoli & Janssen 2009, p. 8, pl. 4a���c; Sadeghi & Loghmani 2010, p. 1, figs 2���3; Angeletti et al. 2018, p. 374, fig. 6, Blatterer 2019, p. 52, Fig. 3 f-g, pl. 3, fig. 6 a-e. Type material. MNHN, lectotype and paralectotype designated by Ferreira (1986). Type locality. Suez, Egypt. Material examined. Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd): St. 3: 11 valves (1 head, width 18.5 mm, and 10 intermediate, maximum width 29 mm), Figs 17 A���C (MZB 50554); St. 6: 1 intermediate valve, width 24.5 mm (MZB 60261); St. 9: 1 intermediate valve (figured in Angeletti et al. 2018). Egypt, Shaw��r��ţ island.: St. 19: 1 intermediate valve, width 27.5 mm (MZB 60274). Description. Head valve nearly semicircular. Intermediate valves broadly rectangular to widely V-shaped, side margins rounded, apex blunt, lateral areas little or not raised, hardly marked. Tegmental sculpture often indistinguishable on account of erosion and encrustation, consists of roundish tubercles irregularly arranged, ocelli very small, abundantly distributed on end valves and more than half lateral areas of intermediate valves. Articulamentum glossy, apophyses large, rounded, connected across the sinus by a short, concave jugal plate, slit formula 10/I/ 9���10, teeth short, deeply grooved on the dorsal side, pectinate. Remarks. This is the only species of Acanthopleura known to live in the northern Red Sea, and is also the largest Red Sea chiton (reaching �� 100 mm in length). The determination of Acanthopleura species is often difficult due to their high degree of intraspecific variability, similarity between congeneric species, and frequent erosion on the dorsal parts of plates. Ferreira (1983, 1986) considered all the Red Sea specimens to belong to A. gemmata (de Blainville, 1825), while Kaas & Van Belle (1988) and Strack (1993) regarded the Red Sea, Yemen, Oman and Arabian Gulf populations as distinct from A. gemmata, A. vaillantii de Rochebrune, 1882 being the oldest available name for these. The Red Sea specimens were also determined in early publications as Chiton spiniger Sowerby, 1840 (now considered a synonym of A. gemmata) and Acanthopleura haddoni Winckworth, 1927 (Brooker 2003). Acanthopleura vaillantii inhabits the intertidal zone and is therefore an excellent sea-level indicator in paleoecological studies (Angeletti et al. 2018). However, on-land occurrences of loose plates could be misleading for geological purposes due to collection and displacement by humans rather than representing genuine ecological settings (M. Taviani, pers. observ.). Distribution. Late Pleistocene: Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study); Egypt (Hurghada: Issel 1869; Shawarit isl.: this study). Present-day: Red Sea, Yemen, Socotra Island, Oman, Iran, and the entrance of the Arabian Gulf (Kaas et al. 2006; Dinapoli & Janssen 2009; Blatterer 2019)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on pages 428-429, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Rochebrune, A. T. de (1882) Monographie des especes fossiles appartenant a la classe des Polyplaxiphores. Annales des Sciences Geologiques, 14, 1 - 74, pls. 1 - 3.","Issel, A. (1869) Malacologia del Mar Rosso. Ricerche zoologiche e paleontologiche. Parte terza. Catalogo delle conchiglie fossili raccolte sulle spiagge emerse del Mar Rosso. Biblioteca Malacologica, Pisa, 61 pp. [pp. 243 - 303]","Ferreira, A. J. (1983) Researches on the coast of Somalia. The chiton fauna (Mollusca Polyplacophora). Monitore Zoologico Italiano, 9, 249 - 297. https: // doi. org / 10.1080 / 00269786.1983.11758574","Vine, P. (1986) Red Sea Invertebrates. IMMEL Publishing, London, 224 pp.","Ferreira, A. J. (1986) A revision of the genus Acanthopleura Guilding, 1829 (Mollusca: Polyplacophora). The Veliger, 28, 221 - 279.","Kaas, P. & Van Belle, R. A. (1988) Chitons (Mollusca: Polyplacophora) from the coasts of Oman and the Arabian Gulf. American Malacological Bulletin, 6, 115 - 130.","Strack, H. L. (1993) The Polyplacophora of the Red Sea. Journal of the Malacological Society of Australia, 14, 1 - 40. https: // doi. org / 10.1080 / 00852988.1993.11923901","Bosch, D. T., Dance, S. P., Moolenbeek, R. G. & Oliver, P. G. (1995) Seashells of Eastern Arabia. Motivate Publishing, Dubai, 290 pp.","Dekker, H. & Orlin, Z. (2000) Check-list of Red Sea Mollusca. Spirula, 47 (Supplement), 1 - 46.","Slieker, F. J. A. (2000) Chitons of the world. An illustrated synopsis of recent Polyplacophora. L'Informatore Piceno Ed., Ancona, 154 pp.","Brooker, L. R. (2003) Revision of Acanthopleura Guilding, 1829 (Mollusca: Polyplacophora) based on light and electron microscopy. Thesis, Murdoch University, Perth, xiii + 528 pp.","Abubakr, M. M. (2004) The Republic of Yemen Marine Biotic Ecosystem (Resources-Habitats and Species). Ministry of Water and Environment, Environment Protection Authority, Aden, 128 pp.","Anseeuw, B. & Terryn, Y. (2004) Intertidal chitons (Mollusca: Polyplacophora) from the coast of Jordan, Red Sea, with the description of a new species of Parachiton Thiele, 1909. Bollettino Malacologico, Supplement 5, 1 - 24.","Kaas, P., Van Belle, R. A. & Strack, H. L. (2006) Monograph of Living Chitons (Mollusca: Polyplacophora). Volume 6. Suborder Ischnochitonina (concluded): Schizochitonidae; Chitonidae. Additions to Volumes 1 - 5. E. J. Brill, Leiden-Boston, 463 pp.","Dekker, H. & Gemert, L. J. van (2008) A new list with corrections to the shells pictured in \" Red Sea Shells \" (1984) by Doreen Sharabati. De Kreukel, 44, 123 - 136.","Dinapoli, A. & Janssen, R. (2009) Polyplacophora (Mollusca) of the Socotra Arcipelago - Systematics and Biogeography. Fauna of Arabia, 24, 1 - 46.","Sadeghi, P. & Loghmani, M. (2010) First record of Acanthopleura vaillantii (Mollusca: Polyplacophora) from Iran-Chabahar Bay in the Oman Sea. Biodiversity Records, 3, e 7. https: // doi. org / 10.1017 / S 1755267209990984","Angeletti, L., Rasul, N. M. A. & Taviani, M. (2018) Mollusc fauna associated with Late Pleistocene coral reef systems of the Saudi Arabian side of the Gulf of Aqaba. In: Rasul, N. M. A. & Stewart, C. F. (Eds.), Geological Setting, Palaeoenvironment and Archaeology of the Red Sea, Springer, Cham, pp. 367 - 387. https: // doi. org / 10.1007 / 978 - 3 - 319 - 99408 - 6 _ 17","Blatterer, H. (2019) Mollusca of the Dahab region. Oberosterreichisches Landesmuseum, Linz, Austria, 480 pp.","Blainville, H. M. D. de (1825) Oscabrelle. Oscabrion. In: F. Cuvier (Ed.), Dictionnaire des Sciences Naturelles. Vol. 36. F. G. Levrault, Paris & Le Normant, Strasbourg, pp. 519 - 556.","Winckworth, R. (1927) New species of chitons from Aden and South India. Proceedings of the Malacological Society of London, 17, 206 - 208, pls. 28 - 29."]}

Lucilina sueziensis (Reeve, 1847) (Fig. 9) Chiton sueziensis Reeve 1847, pl. 20, fig. 134. Chiton (Tonicia) sueziensis; Issel 1869, p. 235; Moazzo 1939, p. 220. Chiton (Tonicia) sp.; Issel 1869, p. 318 (ex Savigny pl. 3, fig. 7). Tonicia suezensis (sic); Sykes 1907, p. 34; Leloup 1960, p. 40, figs 6, 8, pl. 1, fig. 1; Leloup 1980, p. 12; Vine 1986, p. 125. Lucilina sueziensis; Lamy 1938, p. 88; Blatterer 2019, p. 52, pl. 4, fig. 10 a���n. Tonicia sueziensis; Ferreira 1983, p. 271, figs 25���28; Dekker & Orlin 2000, p. 7; Slieker 2000, p. 50, fig. 28; Abubakr 2004, p. 73; Dell���Angelo et al. 2004, p. 56. Tonicia (Lucilina) sueziensis; Kaas & Van Belle 1988, p. 124, figs 41���44; Van Belle & Wranik 1991, p. 375, fig. 21; Strack 1993, p. 19, pl. 5, fig. 1, pl. 6, figs 1���2; Bosch et al. 1995, p. 191; Kaas & Van Belle 1998, p. 182; Anseeuw & Terryn 2004, p. 15, figs 5, 50���54; Kaas et al. 2006, p. 315, fig. 129, map 158; Dinapoli & Janssen 2009, p. 20, pl. 11 a���d. Tonicia (Lucinila) (sic) sueziensis; Mohammadian 2011, p. 211. Non Chiton (Tonicia) sueziensis; Issel 1869, p. 317 (ex Savigny pl. 3, fig. 4) (= Acanthopleura vaillantii de Rochebrune, 1882, juv., fide Kaas et al. 2006). Type material. BMNH 1591.2.7.7, lectotype designed by Ferreira (1983: 272, figs 26���27). Type locality. Gulf of Suez. Material examined. Jordan, Aqaba (Yamanie) (St. 1): 5 valves (4 intermediate and 1 tail) (MZB 60254). Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study): St. 4: 4 intermediate valves (MZB 60255); St. 5: 3 intermediate valves (MZB 60256); St. 7: 5 valves (4 intermediate and 1 tail) (MZB 60257); St. 8: 7 valves (3 head and 4 intermediate), Fig. 9J (MZB 50534); St. 9: 4 valves (1 head, 1 intermediate and 2 tail), Fig. 9L (MZB 50535). Egypt, Hurghada: St. 12: 20 valves (2 head, 13 intermediate and 5 tail) (BD 198); St. 13: 108 valves (13 head, 70 intermediate and 25 tail), Figs 9 A���I (BD 199; MZB 50533 a���c; RGM.1356854); St. 14: 28 valves (3 head and 25 intermediate) (BD 200); St. 14bis: 17 valves (11 intermediate and 6 tail), Fig. 9K (BD 201; MZB 50533 d); St. 16: 46 valves (5 head, 35 intermediate and 6 tail) (BD 202); St. 17: 1 tail valve (BD 203). Maximum width: 3.8 / 5.7 / 7.5 mm. Description. Head valve semicircular, posterior margin widely V-shaped, straight to weakly convex at both sides of minute apical notch, front slope slightly convex, tegmentum coarsely sculptured with up to 20 radial rows of small, warty, V-shaped rugosities, interstices each with row of minute, round to oval, black ocelli. Intermediate valves rectangular, L/W = 0.33���0.40, front margin slightly sinuous, concave in wide central part, convex at pleurae, moderately elevated (H/W = 0.34���0.41), anterior profile subcarinated, side margins rounded, posterior margin concave at both sides of bluntly protruding apex, lateral areas not raised, sculptured like head valve, 2���4 radial rows, the anterior one with larger rugosities, defining the diagonal line, ocelli anterior on 1/3 to 1/2 of lateral area, pleural areas with up to 14 longitudinal, sinuous, slightly granulose wrinkles, fanning out anteriorly, diverging at sides, converging and gradually shortening towards wide, smooth jugal area. Tail valve semicircular, L/W = 0.51���0.56, front margin evenly convex, straight in jugal part, mucro subcentral, not prominent, antemucronal and postmucronal slopes straight, some valves with postmucronal slope steep, strongly convex, antemucronal area sculptured like central areas, postmucronal area like head valve. Articulamentum with apophyses wide, triangular, trapezoidal in tail valve, connected across wide, shallow sinus by short, pectinated, jugal plate, insertion plates rather long, slit formula 8���10/1/10-12, teeth strongly fluted on outside, eaves narrow, solid. Remarks. Lucilina sueziensis is a highly variable species, especially in regards to the sculpture of the tegmentum (Ferreira 1983; Strack 1993; Anseeuw & Terryn 2004). The mucro of the tail valve is normally in a subcentral position, with antemucronal and postmucronal slopes almost straight or slightly concave (Fig. 9I), but some tail valves show a variability in morphology, with the mucro in a more posterior position, and the antemucronal and postmucronal slopes much more convex (Figs 9 K���L). Ferreira (1983: 271) noted in the description of the tail valve ���mucro prominent, central to slightly posterior; postmucro sloping at 30���45�� (steeper in larger specimens)���, agreeing with the valve illustrated in Fig. 9I, but the lectotype selected and figured (Ferreira 1983: fig 27���28) shows a postmucronal slope more similar to the valves illustrated in Fig. 9 K���L. A similar species is Lucilina carnosa (Kaas, 1979) from Madagascar, Mozambique, R��union, Seychelles, Amirante, and Maldive Islands. That species was synonymised with L. sueziensis by Ferreira (1983), but differs in having stronger sculpture, the tail valve subtriangular, as well as various details of the girdle (Kaas et al. 2006), and the two are therefore not synonymous. The main characters of the intermediate valves of Lucilina sueziensis are reported in Tab. 3. Distribution. Late Pleistocene: Jordan, Aqaba, (Yamanie); Saudi Arabia, Gulf of Aqaba (Ash Shaykh Humayd: this study); Egypt (Hurghada: Issel, 1869; this study). Present-day: Indian Ocean: Red Sea, Gulf of Suez, Gulf of Aden, Somalia, Seychelles, Rodriguez, and Socotra Islands (Dinapoli & Janssen 2009; Kaas et al. 2006; Blatterer 2019)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on pages 415-417, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Reeve, L. (1847) Conchologia iconica, or illustrations of the shells of molluscous animals. Monograph of the genus Chiton. Vol. 4. Reeve, Brothers, London, 64 pp., 28 pls. [pp. 21 - 84]","Issel, A. (1869) Malacologia del Mar Rosso. Ricerche zoologiche e paleontologiche. Parte terza. Catalogo delle conchiglie fossili raccolte sulle spiagge emerse del Mar Rosso. Biblioteca Malacologica, Pisa, 61 pp. [pp. 243 - 303]","Moazzo, P. G. (1939) Mollusques testaces marins du Canal de Suez. Memoires de l'Institut d'Egypte, 38, 1 - 287.","Sykes, E. R. (1907) Reports on the marine biology of the Sudanese Red Sea. 5. On the Polyplacophora or chitons. Journal of the Linnean Society of London, 31, 31 - 34. https: // doi. org / 10.1111 / j. 1096 - 3642.1907. tb 00450. x","Leloup, E. (1960) Amphineures du golfe d'Aqaba et de la Peninsule Sinai. Sea Fisheries Research Station, Haifa, Bulletin, 29, 29 - 55, pl. 1.","Leloup, E. (1980) Chitons de la Mer Rouge, du golfe de Suez et de la Mediterranee. Bulletin Institut Royale des Sciences Naturelles de Belgique, 52, 1 - 14, 2 pls.","Vine, P. (1986) Red Sea Invertebrates. IMMEL Publishing, London, 224 pp.","Lamy, E. (1938) Mission Robert Ph. Dollfus en Egypte. Societe Misr pour les Pecheries S. S. \" Al Sayad \", Resultats Scientifiques. 2 e Partie. VII Mollusca Testacea. Memoires presentees a l'Institut d'Egypte, 37, 1 - 90, 1 pl.","Blatterer, H. (2019) Mollusca of the Dahab region. Oberosterreichisches Landesmuseum, Linz, Austria, 480 pp.","Ferreira, A. J. (1983) Researches on the coast of Somalia. The chiton fauna (Mollusca Polyplacophora). Monitore Zoologico Italiano, 9, 249 - 297. https: // doi. org / 10.1080 / 00269786.1983.11758574","Dekker, H. & Orlin, Z. (2000) Check-list of Red Sea Mollusca. Spirula, 47 (Supplement), 1 - 46.","Slieker, F. J. A. (2000) Chitons of the world. An illustrated synopsis of recent Polyplacophora. L'Informatore Piceno Ed., Ancona, 154 pp.","Abubakr, M. M. (2004) The Republic of Yemen Marine Biotic Ecosystem (Resources-Habitats and Species). Ministry of Water and Environment, Environment Protection Authority, Aden, 128 pp.","Dell'Angelo, B., Bonfitto, A., Sabelli, B. & Taviani, M. (2004) Chitons (Mollusca, Polyplacophora) from bioclastic sands of the Ifaty-Tulear back reefs (Madagascar, Western Indian Ocean). Bollettino Malacologico, Supplment 5, 45 - 62.","Kaas, P. & Van Belle, R. A. (1988) Chitons (Mollusca: Polyplacophora) from the coasts of Oman and the Arabian Gulf. American Malacological Bulletin, 6, 115 - 130.","Van Belle, R. A. & Wranik, W. (1991) Chitons (Mollusca: Polyplacophora) from the Coasts of Yemen and Socotra Island. Fauna of Saudi Arabia, 12, 366 - 381.","Strack, H. L. (1993) The Polyplacophora of the Red Sea. Journal of the Malacological Society of Australia, 14, 1 - 40. https: // doi. org / 10.1080 / 00852988.1993.11923901","Bosch, D. T., Dance, S. P., Moolenbeek, R. G. & Oliver, P. G. (1995) Seashells of Eastern Arabia. Motivate Publishing, Dubai, 290 pp.","Kaas, P. & Van Belle, R. A. (1998) Catalogue of living chitons (Mollusca, Polyplacophora). Second, revised edition. Backuys Publishers, Leiden, 204 pp.","Anseeuw, B. & Terryn, Y. (2004) Intertidal chitons (Mollusca: Polyplacophora) from the coast of Jordan, Red Sea, with the description of a new species of Parachiton Thiele, 1909. Bollettino Malacologico, Supplement 5, 1 - 24.","Kaas, P., Van Belle, R. A. & Strack, H. L. (2006) Monograph of Living Chitons (Mollusca: Polyplacophora). Volume 6. Suborder Ischnochitonina (concluded): Schizochitonidae; Chitonidae. Additions to Volumes 1 - 5. E. J. Brill, Leiden-Boston, 463 pp.","Dinapoli, A. & Janssen, R. (2009) Polyplacophora (Mollusca) of the Socotra Arcipelago - Systematics and Biogeography. Fauna of Arabia, 24, 1 - 46.","Mohammadian, H. (2011) The molluscs in Iran. Shabpareh Publishing Company, Tehran, 229 pp. [in Arabic script]","Rochebrune, A. T. de (1882) Monographie des especes fossiles appartenant a la classe des Polyplaxiphores. Annales des Sciences Geologiques, 14, 1 - 74, pls. 1 - 3.","Kaas, P. (1979) The Chitons (Mollusca: Polyplacophora) of Mozambique. Annals of the Natal Museum, 23, 855 - 879."]}

Lucilina perligera Thiele, 1909 (Fig. 10) Lucilina perligera Thiele 1909, p. 97, pl. 10, figs 51���52; Kilias 1995, p. 167; Dell���Angelo et al. 2010a, p. 15, figs 5A���B; Blatterer 2019, p. 52, pl. 4, fig. 9 a���k. Tonicia perligera; Leloup 1960, p. 39, fig. 4; Leloup 1980, p. 12; Dekker & Orlin 2000, p. 7; Slieker 2000, p. 50, pl. 13, fig. 27. Tonicia (Lucilina) perligera; Strack 1993, p. 20, pl. 4, figs 7���9; Kaas & Van Belle 1998, p. 142; Anseeuw & Terryn 2004, p. 15, figs 24���31, 48���49; Kaas et al. 2006, p. 319, fig. 131, map 18. Non Tonicia perligera; Ferreira 1983, p. 274 (= Lucilina sueziensis, fide Strack 1993, p. 21). Type material. Holotype ZMHU Moll. 102059. Type locality. Red Sea. Material examined. Egypt, Hurghada: St. 13: 1 head valve, width 4 mm (Figs 10 A���C) (MZB 50536); St. 14 bis: 1 head valve, width 3 mm, Fig. 10D (MZB 50537). Recent material examined. Israel, Eilat (P448A): 7 valves (3 head, 2 intermediate and 2 tail), Figs 10 E���I (BD 204; MZB 50538). Description. Head valve semicircular, posterior margin almost straight, front slope slightly convex, tegmentum sculptured with quincuncially dispersed, large, clearly separated, highly elevated, roundish granules, diameter ca 120���160 ��m, ocelli minute, black, randomly dispersed. Articulamentum worn and incomplete. Remarks. The present material most resembles Lucilina perligera Thiele, 1909. A detailed description of that species, characterised by the tegmentum sculptured with large, widely separated granules, was given by Kaas et al. (2006). Two head valves at hand have the same type of sculpture, but with the granules more widely spaced (Figs 10A, D). We report a Recent head valve of Lucilina perligera from the Gulf of Aqaba (Figs 10 E���F), with the denser sculpture of close-set granules more typical for this species. The granules have the same roundish/oval shape and are of comparable dimensions, diameter ca 120���160 ��m in the fossil valve (Fig.10B), ca 140���180 ��m in the living valve (Fig. 10F). The diameter of the granules is variable, Strack (1993: 21) reported a diameter of 130���150 ��m in the holotype, and up to 260 ��m in loose valves studied; Anseeuw & Terryn (2004: 16) gave a diameter up to 280 ��m. The only difference between the head valves of living and fossil specimens seems to be the smaller, wider-spaced granules on the tegmentum in the fossil ones. We also illustrate, for completeness and for comparison with the other species of Lucilina described here, an intermediate and a tail valve of L. perligera from the Gulf of Aqaba (Figs 10 G���I). Lucilina perligera resembles L. sueziensis (see above) in many respects, but can be easily differentiated by the sculpture of the tegmentum, which has large, widely spaced granules. This is the first report of this species as a fossil. Distribution. Late Pleistocene: Egypt, Hurghada (this study). Present-day: northern Red Sea and Maldive Islands (Dell���Angelo et al. 2010a; Kaas et al. 2006; Blatterer 2019)., Published as part of Dell'Angelo, Bruno, Landau, Bernard M., Sosso, Maurizio & Taviani, Marco, 2020, Late Pleistocene Red Sea Mollusca: 1. Polyplacophora, pp. 401-449 in Zootaxa 4772 (3) on pages 417-418, DOI: 10.11646/zootaxa.4772.3.1, http://zenodo.org/record/3819654, {"references":["Thiele, J. (1909) Revision des Systems der Chitonen. Zoologica, 22, 1 - 132, pls. 1 - 10. https: // doi. org / 10.5962 / bhl. title. 11245","Kilias, R. (1995) Polyplacophora-Typen und - Typoide (Mollusca) im Zoologischen Museum in Berlin. Mitteilungen aus dem Zoologischen Museum in Berlin, 71, 155 - 170. https: // doi. org / 10.1002 / mmnz. 19950710118","Dell'Angelo, B., Gori, S., Baschieri, L. & Bonfitto, A. (2010 a) Chitons (Mollusca, Polyplacophora) from the Maldive islands. Zootaxa, 2673 (1), 1 - 38. https: // doi. org / 10.11646 / zootaxa. 2673.1.1","Blatterer, H. (2019) Mollusca of the Dahab region. Oberosterreichisches Landesmuseum, Linz, Austria, 480 pp.","Leloup, E. (1960) Amphineures du golfe d'Aqaba et de la Peninsule Sinai. Sea Fisheries Research Station, Haifa, Bulletin, 29, 29 - 55, pl. 1.","Leloup, E. (1980) Chitons de la Mer Rouge, du golfe de Suez et de la Mediterranee. Bulletin Institut Royale des Sciences Naturelles de Belgique, 52, 1 - 14, 2 pls.","Dekker, H. & Orlin, Z. (2000) Check-list of Red Sea Mollusca. Spirula, 47 (Supplement), 1 - 46.","Slieker, F. J. A. (2000) Chitons of the world. An illustrated synopsis of recent Polyplacophora. L'Informatore Piceno Ed., Ancona, 154 pp.","Strack, H. L. (1993) The Polyplacophora of the Red Sea. Journal of the Malacological Society of Australia, 14, 1 - 40. https: // doi. org / 10.1080 / 00852988.1993.11923901","Kaas, P. & Van Belle, R. A. (1998) Catalogue of living chitons (Mollusca, Polyplacophora). Second, revised edition. Backuys Publishers, Leiden, 204 pp.","Anseeuw, B. & Terryn, Y. (2004) Intertidal chitons (Mollusca: Polyplacophora) from the coast of Jordan, Red Sea, with the description of a new species of Parachiton Thiele, 1909. Bollettino Malacologico, Supplement 5, 1 - 24.","Kaas, P., Van Belle, R. A. & Strack, H. L. (2006) Monograph of Living Chitons (Mollusca: Polyplacophora). Volume 6. Suborder Ischnochitonina (concluded): Schizochitonidae; Chitonidae. Additions to Volumes 1 - 5. E. J. Brill, Leiden-Boston, 463 pp.","Ferreira, A. J. (1983) Researches on the coast of Somalia. The chiton fauna (Mollusca Polyplacophora). Monitore Zoologico Italiano, 9, 249 - 297. https: // doi. org / 10.1080 / 00269786.1983.11758574"]}

Rhyssoplax canariensis (d’Orbigny, 1839) Figs 9F–N Chiton canariensis: d’Orbigny 1839: 99, pl. 7, figs 18–19; Gray 1854: 19; MacAndrew 1856: 117; Nierstrasz 1906: 515; Thiele 1909: 6; Lamy 1907: 151; Bergenhayn 1931: 18, pl. 1, figs 30–33, pl. 3, fig. 66; Nickles 1950: 14, fig. 3; Sourie 1954: 239, 299; Marche-Marchad 1958: 11; Leloup 1968 a: 28; Sabelli & Spada 1970: 6; Fischer 1978: 43; Altimira & Ros 1979: 9; Bernard 1984: 122, pl. 63; Poppe & Goto 1991: 60, pl. 1, fig. 12; Slieker 2000: 32, pl. 4, figs 39, 39a; Ardovini & Cossignani 2004: 18, figs p. 58. Type material: NHMUK 1854.9.28.152, 3 Syntypes (Figs 9H–J). Type locality: Canary Islands. Chiton (Lophurus) canariensis: Shuttleworth 1853: 205. Chiton (Gymnoplax) canariensis: Dautzenberg 1910: 108; 1912: 80. Chiton (Rhyssoplax) canariensis: Van Belle 1984 a: 101, pl. 3; Strack 1987: 181; Gerber et al. 1989: 22; Kaas 1991: 94; Kaas et al. 2006: 156, fig. 57 (chresonymy and synonymy); Rolán 2011: 50, figs 4I–T. Chiton lyratus Sowerby 1840 a: fig. 126 (nom. nud.); 1840 b: 293; Reeve 1847: pl. xviii, species 110; Pilsbry 1893: 184, pl. 31, figs 35–36; Nierstrasz 1906: 515; Tomlin & Shackleford 1915: 269; Fernandes & Rolán 1993: 33. Type material: NHMUK 1979176, 2 Syntypes (Figs 9F–G). Type locality: unknown (Prince Island, West Africa, fide Reeve 1847). Material examined: ST01: 2 specimens in alcohol, maximum length 11 mm (ZSM Mol-20080400); ST02: 5 specimens, maximum length 20 mm (Figs 9L, 9N) (BD 119 A); ST03: 38 specimens, maximum length 22 mm (Figs 9K, 9M) (BD 119 B); ST03: 1 specimen in alcohol, length 21 mm (ZSM Mol- 20071398), and 81 valves (14 head, maximum width 5 mm, 54 intermediate, maximum width 8 mm, and 13 tail, maximum width 4.2 mm) (BD 119 C, ER); ST05: 6 specimens, maximum length 13 mm (BD 119 D); ST07: 3 specimens, maximum length 26 mm (BD 119 E); ST09: 8 specimens in alcohol, maximum length 15 mm (ZSM Mol-20040494); ST09: 3 specimens in alcohol, maximum length 14 mm (ZSM Mol-20040503); ST10: 7 specimens in alcohol, maximum length 15 mm (ZSM Mol-20034143); ST10: 1 specimen in alcohol, length 6 mm (ZSM Mol-20034149); ST11: 10 valves (3 head, maximum width 3.5 mm, and 7 intermediate, maximum width 3.5 mm) (BD 119 F); PR 01: 5 specimens, maximum length 19 mm (BD 119 G); PR 02: 2 specimens, maximum length 18.5 mm (BD 119 H); PR 03: 1 specimen, maximum length 16 mm (BD 119 I); PR 04: 1 specimen in alcohol, length 26 mm (BD 119 J); PR 06: 11 specimens in alcohol, maximum length 21 mm (ZSM Mol-20040208); PR 07: 9 intermediate valves, maximum width 7.2 mm (BD 119 K). Distribution: Rhyssoplax canariensis is a common subtidal species, reported from the Canary Islands and western Africa, from Morocco to Angola (Kaas et al. 2006), and the São Tomé and Príncipe Islands. It does not occur in the Cape Verde and Madeira archipelagos except for one report from Porto Santo, Madeira, as a Pleistocene fossil (Gerber et al. 1989). Comparison and remarks: Chiton lyratus is considered a synonym of Rhyssoplax canariensis, as already reported by Pilsbry (1893: 184). Syntypes of both taxa are illustrated (Figs 9F–G, 9H–J). The examination of the 100 valves found gives a slit formula of 8–9 / 1 / 10–13 vs. 8 / 1 / 7–11, reported by Kaas et al. (2006), which can be considered to be within the range of acceptable variation for a common and widely-distributed species. Only one intermediate valve with 2 slits on the right side was found, out of a total of 70 intermediate valves checked. A unique head valve from ST03 has a shell scar due to injury, which caused the development of a new insertion plate under the older one in the articulamentum., Published as part of Dell'Angelo, Bruno, Schwabe, Enrico, Gori, Sandro, Sosso, Maurizio & Bonfitto, Antonio, 2014, Chitons (Mollusca, Polyplacophora) from São Tomé and Príncipe Islands, pp. 171-200 in African Invertebrates 55 (2) on pages 185-187, DOI: 10.5281/zenodo.7680891, {"references":["MACANDREW, R. 1856. Report on the marine testaceous Mollusca of the north-east Atlantic and neighbouring seas. Report of the British Association for the Advancement of Science for 1856: 101 - 158.","NIERSTRASZ, H. F. 1906. Beitrage zur Kenntnis der Fauna von Sud-Afrika. VI. Chitonen aus der Kapkolonie und Natal. Zoologischen Jahrbuchern, Abteilung fur Systematik, Geografie und Biologie der Tiere 23 (4): 487 - 520, pls 26 - 27.","LAMY, E. 1907. Liste des coquilles marines recueillies par M. Ch. Gravier a l'Ile Sao Thome (1906). Bulletin du Museum d'Histoire Naturelle, Serie 1, 13 (2): 145 - 154.","BERGENHAYN, J. R. M. 1931. Beitrage zur Malakozoologie der Kanarischen Inseln. Die Loricaten. Arkiv for Zoologi, Stockholm 23 A: 1 - 38, 3 pls.","NICKLES, M. 1950. Mollusques testaces marins de la cote occidentale d'Afrique. Paris: Paul Lechevalier.","SOURIE, R. 1954. Contribution a l'etude ecologique des cotes rocheuses du Senegal. Memoires de l'I. F. A. N. 38: 1 - 342.","SABELLI, B. & SPADA, G. 1970. Chiton olivaceus Spengler, 1797. Schede Malacologiche del Mediterraneo Serie 87 Ea 01: 1 - 6.","FISCHER, P. - H. 1978. L'habitat littoral parmi les mollusques polyplacophores. Journal de Conchyliologie 115: 30 - 55.","ALTIMIRA, C. & ROS, J. 1979. Algunos moluscos marinos de las Islas Canarias. Vieraea 8: 3 - 12.","BERNARD, P. A. 1984. Coquillages du Gabon. Rome: La Piramide.","POPPE, G. T. & GOTO, Y. 1991. European seashells. Vol. I (Polyplacophora, Caudofoveata, Solenogastra, Gastropoda). Wiesbaden: Christa Hemmen.","SLIEKER, F. J. A. 2000. Chitons of the world. An illustrated synopsis of recent Polyplacophora. Ancona: L'Informatore Piceno.","ARDOVINI, R. & COSSIGNANI, T. 2004. West African seashells (including Azores, Madeira and Canary Is.). Ancona: L'Informatore Piceno.","SHUTTLEWORTH, R. J. 1853. Diagnosen neuer Mollusken. 4, Uber den Bau der Chitoniden, mit Aufzahlung der die Antillen und die Canarischen Inseln bewohnenden Arten. Mitteilungen der Naturforschenden Gesellschaft in Bern 286 - 291: 169 - 207.","DAUTZENBERG, P. 1910. Contribution a la faune malacologique de l'Afrique occidentale. Actes de la Societe Linneenne de Bordeaux 64: 1 - 174, pls 1 - 4.","VAN BELLE, R. A. 1984 a. De Polyplacophora van de Canarische Eilanden. Gloria Maris 23: 95 - 106.","STRACK, H. L. 1987. The Polyplacophora of Gran Canaria, including a worldwide survey of the brooding species. Iberus 7: 179 - 187.","GERBER, J., HEMMEN, J. & GROH, K. 1989. Eine pleistozane marine Molluskenfauna von Porto Santo (Madeira- Archipel). Mitteilungen der Deutschen Malakozoologischen Gesellschaft 44 - 45: 19 - 30.","KAAS, P., VAN BELLE, R. A. & STRACK, H. L. 2006. Monograph of living chitons (Mollusca: Polyplacophora). Volume 6. Suborder Ischnochitonina (concluded): Schizochitonidae; Chitonidae. Additions to volumes 1 - 5. Leiden: E. J. Brill.","SOWERBY, G. B. II. 1840 a. The conchological illustrations, or coloured figures of all the hitherto unfigured recent shells. London: Sowerby, parts 38 - 45 (1833), 159 - 177 (1839 - 1840).","REEVE, L. 1847 - 1848. Conchologia iconica, or illustrations of the shells of molluscous animals. London: Reeve. Vol. 4: Monograph of the genus Chitonellus: pl. 1; Monograph of the genus Chiton: pls 1 - 27 (1847), pl. 28 (1848).","KAAS, P. & STRACK, H. L. 1986. Two new species of Lepidochitona Gray, 1821 (Polyplacophora: Ischnochitonidae) from Senegal and the Cabo Verde archipelago. Basteria 50: 79 - 86.","PENNANT, T. 1777. British Zoology. Crustacea. Mollusca. Testacea. London: B. White."]}

Lepidochitona rolani Kaas & Strack, 1986 Figs 6A–F Lepidochitona rolani Kaas & Strack 1986: 83, figs 1, 16–28; Kaas & Van Belle 1987: 33, fig. 15; Kaas 1991: 91; Rolán 2005: 27, fig. 3. Type material: Holotype in MNCN. Paratypes: Many specimens in several institutions (see Kaas & Strack 1986). Type locality: Cape Verde Archipelago, São Vicente, Calhão, intertidal. Material examined: ST06: 1 specimen, length 2 mm, and 7 valves (2 head, maximum width 2.2 mm, and 5 intermediate, maximum width 3 mm) (BD 120A); ST11: 3 valves (2 intermediate, maximum width 2.2mm, and 1 tail, width 2.1 mm) (BD 120B); PR05: 5 intermediate valves, maximum width 2.5 mm (ER); PR07: 13 valves (2 head, maximum width 2.8 mm, 10 intermediate, maximum width 3.7 mm, and 1 tail, width 1.6 mm) (BD 120C). Distribution: Cape Verde Archipelago, and São Tomé and Príncipe Islands. Comparison and remarks: The material examined was a unique, small living specimen (Fig. 6A) and many separate valves, well defined by the rounded intermediate valves, and by the characteristic microsculpture (Figs 6D, 6F). All are characters that agree well with the original description given by Kaas and Strack (1986)., Published as part of Dell'Angelo, Bruno, Schwabe, Enrico, Gori, Sandro, Sosso, Maurizio & Bonfitto, Antonio, 2014, Chitons (Mollusca, Polyplacophora) from São Tomé and Príncipe Islands, pp. 171-200 in African Invertebrates 55 (2) on page 187, DOI: 10.5281/zenodo.7680891, {"references":["KAAS, P. & STRACK, H. L. 1986. Two new species of Lepidochitona Gray, 1821 (Polyplacophora: Ischnochitonidae) from Senegal and the Cabo Verde archipelago. Basteria 50: 79 - 86.","ROLAN, E. 2005. Malacological fauna from the Cape Verde archipelago. Part 1. Polyplacophora and Gastropoda. Germany: ConchBooks."]}

Ischnochiton sp. Figs 2L–Q Material examined: ST06: 1 specimen, length 2 mm (BD 108). Distribution: São Tomé Island. Comparison and remarks: This specimen is characterized by a tegmental sculpture consisting of rough and closely spaced nodules, irregular in outline and irregularly distributed (Figs 2O–P). The dorsal girdle is beset with rectangular overlapping scales, bearing up to 11 strong ribs (Fig. 2Q). Only five species of Ischnochiton are known from the northern and central Atlantic African coasts and islands, namely I. sererorum (de Rochebrune, 1881) from Mauritania and Cape Verde Islands, I. cessaci (de Rochebrune, 1881) from Mauritania, Senegal, Angola, Canary Islands and Cape Verde Islands, I. goreensis Thiele, 1909 from Senegal and Cape Verde Islands, I. paessleri Thiele, 1909 from Cape Verde Islands, and I. nicklesi Kaas & Van Belle, 1990, from Senegal and Cape Verde Islands (Kaas & Van Belle 1990; Rolán 2005, 2011). However, all have a tegmental sculpture that is mainly smooth or finely granulose. Congeners from South African Atlantic waters, namely I. textilis (Gray, 1828), I. oniscus (Krauss, 1848), I. bergoti (Vélain, 1877), and I. elizabethensis Pilsbry, 1894, could also be found along part of the southwest African coast but differ from the present specimen not only in their generally larger size, but they also have morphological peculiarities, summarized in Kaas and Van Belle (1990) and Sirenko and Schwabe (2002), that are lacking in this specimen, although their juvenile stages have not been carefully compared. Description of a new species on the basis of the single small specimen is not justified, so it is preferable to leave the identification as Ischnochiton sp. until such time as more material becomes available., Published as part of Dell'Angelo, Bruno, Schwabe, Enrico, Gori, Sandro, Sosso, Maurizio & Bonfitto, Antonio, 2014, Chitons (Mollusca, Polyplacophora) from São Tomé and Príncipe Islands, pp. 171-200 in African Invertebrates 55 (2) on page 176, DOI: 10.5281/zenodo.7680891, {"references":["DE ROCHEBRUNE, A. T. 1881. Diagnoses specierum novarum familiae Chitonidarum. Journal de Conchyliologie (3), 21: 42 - 46.","ROLAN, E. 2005. Malacological fauna from the Cape Verde archipelago. Part 1. Polyplacophora and Gastropoda. Germany: ConchBooks.","SIRENKO, B. & SCHWABE, E. 2002. Taxonomic notes on chitons. 2. Taxonomic status of chitons of the Ischnochiton oniscus group (Mollusca, Polyplacophora, Ischnochitonidae). Spixiana 25: 193 - 198."]}

Genus Chaetopleura Shuttleworth, 1853 Chaetopleura: Shuttleworth 1853: 182. Type species: Chiton peruvianus Lamarck, 1819, by subsequent designation (Dall 1879: 296). For synonymy, see Kaas & Van Belle (1987). Distribution: Worldwide, but most species occur in the tropical and subtropical regions of Africa, and South and Central America (Schwabe 2006). Oligocene – Recent., Published as part of Dell'Angelo, Bruno, Schwabe, Enrico, Gori, Sandro, Sosso, Maurizio & Bonfitto, Antonio, 2014, Chitons (Mollusca, Polyplacophora) from São Tomé and Príncipe Islands, pp. 171-200 in African Invertebrates 55 (2) on page 181, DOI: 10.5281/zenodo.7680891, {"references":["SHUTTLEWORTH, R. J. 1853. Diagnosen neuer Mollusken. 4, Uber den Bau der Chitoniden, mit Aufzahlung der die Antillen und die Canarischen Inseln bewohnenden Arten. Mitteilungen der Naturforschenden Gesellschaft in Bern 286 - 291: 169 - 207.","DALL, W. H. 1879. Report on the limpets and chitons of the Alaskan and Arctic regions, with descriptions of genera and species believed to be new. Proceedings of the United States National Museum 1: 281 - 344, pls 1 - 5."]}

Notoplax sp. Figs 8G–J Description: Intermediate valve beaked, tegmentum a little wider than long, very reduced in the anterior portion, with anterolateral margins sinuose in the upper part, almost straight and obliquely directed in the lower one; sutural laminae very large, separated anteriorly by a wide sinus; lateral margins oblique, with a single slit. Jugum well defined, raised, smooth, separated from the latero-pleural areas. Lateral and pleural areas with similar sculpture of irregularly rounded pustules. Material examined: ST03: 1 intermediate valve, width 2.8 mm (BD 121). Distribution: São Tomé Island. Comparison and remarks: The reduced tegmentum, the very large insertion plates, the pustulose sculpture of the lateropleural areas, and the well defined and narrow jugum support our tentative assignment of this unique intermediate valve to the genus Notoplax, as redefined by Gowlett-Holmes (1991). Our tentative assignment of this valve to Notoplax greatly extends the distribution of the genus, considered to be restricted to Australia and New Zealand by GowlettHolmes (1991), but already widened to Japanese waters by Saito (1995, 1997, 2005 for Notoplax hilgendorfi Thiele, 1909), and Saito (1998, 2004 for Notoplax sp.), and to South Vietnam by Sirenko (2012 for Notoplax sp.). Some species with a similar wing-shaped tegmentum, to date attributed to Acanthochitona, are known, e.g. A. rhodea (Pilsbry, 1893) from the Caribbean coasts of Costa Rica, Panama and Colombia, and A. mastalleri Strack, 1989 from the Red Sea, Oman and Kenya. However, both have a different tegmental layout (Lyons 1988: fig. 12; Strack 1989: pl. 19, fig. 2). This valve may belong to an undescribed species, but additional material is needed to give a complete description of the species., Published as part of Dell'Angelo, Bruno, Schwabe, Enrico, Gori, Sandro, Sosso, Maurizio & Bonfitto, Antonio, 2014, Chitons (Mollusca, Polyplacophora) from São Tomé and Príncipe Islands, pp. 171-200 in African Invertebrates 55 (2) on page 191, DOI: 10.5281/zenodo.7680891, {"references":["GOWLETT- HOLMES, K. L. 1991. Redefinition of the genus Notoplax H. Adams, 1861, and recognition of the monotypic New Zealand genus Pseudotonicia Ashby, 1928 (Mollusca: Polyplacophora: Acanthochitonidae). Journal of the Malacological Society of Australia 12: 77 - 88.","SAITO, H. 1995. The chiton fauna of Onagawa Bay, Northeastern Honshu, Japan. Memoirs of the National Science Museum 28: 99 - 112.","LYONS, W. G. 1988. A review of Caribbean Acanthochitonidae (Mollusca: Polyplacophora) with descriptions of six new species of Acanthochitona Gray, 1821. American Malacological Bulletin 6: 79 - 114."]}

Dell'Angelo, Bruno, Schwabe, Enrico, Gori, Sandro, Sosso, Maurizio, Bonfitto, Antonio (2014): Chitons (Mollusca, Polyplacophora) from São Tomé and Príncipe Islands. African Invertebrates 55 (2): 171-200, DOI: http://doi.org/10.5281/zenodo.7680891, {"references":["ADAMS, H. 1861. Descriptions of some new genera and species of shells from the collection of Hugh Cuming, Esq. Proceedings of the Zoological Society of London, 1861: 383-385.","ALTIMIRA, C. & ROS, J. 1979. Algunos moluscos marinos de las Islas Canarias. Vieraea 8: 3-12.","ARDOVINI, R. & COSSIGNANI, T. 2004. West African seashells (including Azores, Madeira and Canary Is.). Ancona: L'Informatore Piceno.","AVILA, S.P. &ALBERGARIA, A. 2002.The shallow-water Polyplacophora of the Azores and some comments on the biogeographical relationships of the Azorean malacofauna. Bollettino Malacologico 38: 41-44.","AVILA, S.P. & SIGWART, J. 2013. New records for the shallow-water chiton fauna (Mollusca, Polyplacophora) of the Azores (NE Atlantic). ZooKeys 312: 23-38.","BAXTER, J.M. & JONES, A.M. 1984. The valve morphology of Callochiton achatinus (Mollusca: Polyplacophora: Ischnochitonidae). Journal of Zoology, London 202: 549-560.","BERGENHAYN, J.R.M. 1931. Beitrage zur Malakozoologie der Kanarischen Inseln. Die Loricaten. Arkiv for Zoologi, Stockholm 23A: 1-38, 3 pls.","BERNARD, P.A. 1984. Coquillages du Gabon. Rome: La Piramide.","BONFITTO, A., DELL' ANGELO, B., EVANGELISTI, F. & SABELLI, B. 2011. The genus Acanthochitona (Mollusca: Polyplacophora) in the Mediterranean Sea: morphological and molecular data. Scientia Marina 75: 171-180.","CARMONA ZALVIDE, P. & GARCIA, F.J.G. 1999. Consideraciones morfologicas y taxonomicas sobre Ischnochiton (Ischnochiton) rissoi (Payraudeau, 1826) (Mollusca, Polyplacophora). Graellsia 55: 177-186.","CARMONA ZALVIDE, P., GARCIA, F.J. & URGORRI, V. 2002. Consideraciones taxonomicos y zoogeograficas del genero Callochiton Gray, 1847 en la peninsula iberica. Archiv fur Molluskenkunde 131: 185-199.","D' ORBIGNY, A. 1839. Mollusques, echinoderms, foraminiferes et polypiers, recueillis aux Iles Canaries par M.M.Webb et Berthelot. In: Barker-Webb, P. & Berthelot, S., Histoire naturelle des Iles Canaries. Paris: Bethune, 2 (2), Mollusques.","DALL, W.H. 1879. Report on the limpets and chitons of the Alaskan and Arctic regions, with descriptions of genera and species believed to be new. Proceedings of the United States National Museum 1: 281-344, pls 1-5.","DAUTZENBERG, P. 1910. Contribution a la faune malacologique de l'Afrique occidentale. Actes de la Societe Linneenne de Bordeaux 64: 1-174, pls 1-4.","------1912. Mission Gruvel sur la cote occidentale d'Afrique (1909-1910). Mollusques marins. Annales de l'Institut Oceanographique 5: 1-111, pls 1-3.","DE ROCHEBRUNE, A.T. 1881. Diagnoses specierum novarum familiae Chitonidarum.Journal de Conchyliologie (3), 21: 42-46.","------1884. Diagnose d'especes nouvelles de la famille des Chitonidae (deuxieme supplement). Bulletin de la Socete Philomatique (7) 8: 32-39.","DELL' ANGELO, B. & SMRIGLIO, C. 1999. Chitoni viventi del Mediterraneo. Rome: Evolver.","FERNANDES, F. & ROLAN, E. 1991. The Marginellidae (Mollusca, Gastropoda) of Principe Island (Republica de Sao Tome e Principe). Journal of Conchology 34: 85-90.","------1993. Moluscos marinos de Sao Tome y Principe: actualizacion bibliografica y nuevas aportaciones. Iberus 11: 31-47.","FISCHER, P.-H. 1978. L'habitat littoral parmi les mollusques polyplacophores. Journal de Conchyliologie 115: 30-55.","GASCOIGNE, A. 1993. A bibliography of the fauna of the islands of Sao Tome e Principe and the island of Annobon (Gulf of Guinea). Arquipelago - Life and Marine Sciences 11A: 91-105.","------1996. Additions to a bibliography of the fauna of Sao Tome e Principe and the island of Annobon, Gulf of Guinea. Addendum. Arquipelago - Life and Marine Sciences 14A: 95-103.","GERBER, J., HEMMEN, J. & GROH, K. 1989. Eine pleistozane marine Molluskenfauna von Porto Santo (MadeiraArchipel). Mitteilungen der Deutschen Malakozoologischen Gesellschaft 44-45: 19-30.","GOFAS, S. 1995. A remarkable species richness of the Barleiidae (Gastropoda: Rissoacea) in the eastern Atlantic. The Nautilus 109: 14-37.","GOFAS, S. & FERNANDES, F. 1988.The marginellids of Sao Tome,West Africa. Journal of Conchology 33: 1-30.","GOWLETT- HOLMES, K.L. 1991. Redefinition of the genus Notoplax H. Adams, 1861, and recognition of the monotypic New Zealand genus Pseudotonicia Ashby, 1928 (Mollusca: Polyplacophora: Acanthochitonidae). Journal of the Malacological Society of Australia 12: 77-88.","------2001. Polyplacophora. In: Wells, A. & Houston, W.W.K., eds, Zoological catalogue of Australia. Vol. 17.2. Mollusca: Aplacophora, Polyplacophora, Scaphopoda, Cephalopoda. Melbourne: CSIRO Publishing, pp. 19-84.","GRAY, J.E. 1821. A natural arrangement of Mollusca, according to their internal structure. The London Medical Repository 15: 229-239.","------1847a. Additional observations on the chitones. Proceedings of the Zoological Society of London 15: 126-127.","------1847b.A list of the genera of recent Mollusca, their synonyms and types. Proceedings of the Zoological Society of London 15: 129-206.","------1854. List of the shells of the Canaries in the collection of the British Museum. London: Taylor and Francis.","HORRO, J., GORI, S. & ROLAN, E. 2010.Haedropleura ryalli, a new species from Sao Tome Island (Gastropoda, Turridae). Iberus 28: 1-4.","HOUART, R. & ROLAN, E. 2012. The genus Pradoxa Fernandes & Rolan, 1993 (Gastropoda: Muricidae) in Sao Tome, Principe and Annobon. Basteria 30: 1-14.","KAAS, P. 1978. Notes on Loricata, 10. On the European Callochiton species. Basteria 42: 73-75.","------1979. The chitons (Mollusca: Polyplacophora) of Mozambique. Annals of the Natal Museum 23: 855-879.","------1985. The genus Acanthochitona Gray, 1821 (Mollusca, Polyplacophora) in the north-eastern Atlantic ocean and in the Mediterranean Sea, with designation of neotypes of A. fascicularis (L., 1767) and of A. crinita (Pennant, 1777). Bulletin du Museum National d'Histoire Naturelle, Serie 4, A 7: 579-609.","------1986. Revision of the chitons (Mollusca: Polyplacophora) from the coral-reefs of Tulear, SW Madagascar, and of the Mascarene Islands. Mesogee 46: 9-23.","------1989. Chitons (Mollusca, Polyplacophora) procured by the MUSORSTOM 3, Philippines expedition (1985). In: Forest, J., Resultats des Campagnes MUSORSTOM, vol. 4. Memoires du Museum National d'Histoire Naturelle, A 143: 105-111.","------1991. Chitons (Mollusca: Polyplacophora) procured by the CANCAP I-VII expeditions, 1976-86. Zoologische Mededelingen 65: 89-98.","KAAS, P. & STRACK, H.L. 1986. Two new species of Lepidochitona Gray, 1821 (Polyplacophora: Ischnochitonidae) from Senegal and the Cabo Verde archipelago. Basteria 50: 79-86.","KAAS, P. & VAN BELLE, R.A. 1981. The genus Lepidochitona Gray, 1821 (Mollusca: Polyplacophora) in the northeastern Atlantic Ocean, the Mediterranean Sea and the Black Sea. Zoologische Verhandelingen 185: 1-43.","------1985a. Monograph of living chitons (Mollusca: Polyplacophora). Volume 1. Order Neoloricata: Lepidopleurina. Leiden: E.J. Brill - W. Backhuys.","------1985b. Monograph of living chitons (Mollusca: Polyplacophora). Volume 2. Suborder Ischnochitonina, Ischnochitonidae: Schizoplacinae, Callochitoninae & Lepidochitoninae. Leiden: E.J. Brill - W. Backhuys.","------1987.Monograph of living chitons (Mollusca: Polyplacophora). Volume 3. Suborder Ischnochitonina, Ischnochitonidae: Chaetopleurinae & Ischnochitoninae (pars). Additions to vols 1 & 2. Leiden: E.J. Brill - W. Backhuys.","------1990.Monograph of living chitons (Mollusca: Polyplacophora).Volume 4. Suborder Ischnochitonina: Ischnochitonidae: Ischnochitoninae (continued).Additions to volumes 1, 2 and 3. Leiden: E.J. Brill.","------1994.Monograph of living chitons (Mollusca: Polyplacophora).Volume 5. Suborder Ischnochitonina: Ischnochitonidae: Ischnochitoninae (concluded), Callistoplacinae; Mopaliidae. Additions to volumes 1-4. Leiden: E.J. Brill.","------1998.Catalogue of living chitons (Mollusca, Polyplacophora), 2nd ed. Leiden: Backhuys Publishers.","KAAS, P., VAN BELLE, R.A. & STRACK, H.L. 2006. Monograph of living chitons (Mollusca: Polyplacophora). Volume 6. Suborder Ischnochitonina (concluded): Schizochitonidae; Chitonidae. Additions to volumes 1-5. Leiden: E.J. Brill.","LAMY, E. 1907. Liste des coquilles marines recueillies par M. Ch. Gravier a l'Ile Sao Thome (1906). Bulletin du Museum d'Histoire Naturelle,Serie 1, 13 (2): 145-154.","LE LOEUFF, P. & VON COSEL, R. 1998. Biodiversity patterns of the marine benthic fauna on the Atlantic coast of tropical Africa in relation to hydroclimatic conditions and paleographic events. Acta Oecologica 19: 309-321.","LELOUP, E. 1941. A propos de quelques acanthochitons peu connus ou nouveaux II. Region Atlantique. Bulletin du Musee Royal d'Histoire Naturelle de Belgique 17 (43): 1-15.","------1965.Description d'une espece nouvelle de chiton recueillie par la Calypso dans le Golfe de Guinee, Notoplax foresti sp. n. Bulletin du Museum National d'Histoire Naturelle, Serie 2, 37 (1): 155-161.","------1968a. Chitons de la cote Africaine occidentale. Atlantide Report 10: 7-31, pls 1-2.","------1968b. Acanthochitons de la cote Atlantique Africaine. Memorias da Junta de Investigacoes do Ultramar 54: 55-84, figs 1-21.","LOPEZ CABRERA, M.I. & OLIVERO, E.B. 2011. An Eocene articulated Polyplacophora (Mollusca) from the La Meseta formation, Antarctica and the stratigraphy of the fossil-bearing strata. Journal of Paleontology 85: 970-976.","LYONS, W.G. 1988.A review of Caribbean Acanthochitonidae (Mollusca: Polyplacophora) with descriptions of six new species of Acanthochitona Gray, 1821. American Malacological Bulletin 6: 79-114.","MACANDREW, R. 1856. Report on the marine testaceous Mollusca of the north-east Atlantic and neighbouring seas. Report of the British Association for the Advancement of Science for 1856: 101-158.","MARCHE- MARCHAD, I. 1958. Nouveau catalogue de la collection de mollusques testaces marins de l'IFAN. Catalogues 14. Dakar: Institut Francaise d'Afrique Noire.","NICKLES, M. 1950. Mollusques testaces marins de la cote occidentale d'Afrique. Paris: Paul Lechevalier.","NIERSTRASZ, H.F. 1906. Beitrage zur Kenntnis der Fauna von Sud-Afrika. VI. Chitonen aus der Kapkolonie und Natal. Zoologischen Jahrbuchern, Abteilung fur Systematik, Geografie und Biologie der Tiere 23 (4): 487-520, pls 26-27.","PAYRAUDEAU, B.-C. 1826. Catalogue descriptif et methodique des annelides et des mollusques de l'Ile de Corse. Paris: Bechet.","PENNANT, T. 1777. British Zoology. Crustacea. Mollusca. Testacea. London: B. White.","PILSBRY, H.A. 1892-1894. Monograph of Polyplacophora. In: Tryon, G.W., Manual of conchology. Philadelphia: Academy of Natural Sciences, 14: 1-128, pls 1-30 (1892); i-xxxiv, 129-350, pls 31-68 (1893); 15: 1-64, pls 1-10 (1893); 65-133, pls 11-17 (1894).","POPPE, G.T. & GOTO, Y. 1991. European seashells. Vol. I (Polyplacophora, Caudofoveata, Solenogastra, Gastropoda). Wiesbaden: Christa Hemmen.","REEVE, L. 1847-1848. Conchologia iconica, or illustrations of the shells of molluscous animals. London: Reeve. Vol. 4: Monograph of the genus Chitonellus: pl. 1; Monograph of the genus Chiton: pls 1-27 (1847), pl. 28 (1848).","RIGHI, G. 1971. Moluscos poliplacoforos do Brazil. Papeis Avulsos de Zoologia 24: 123-146.","ROLAN, E. 2005. Malacological fauna from the Cape Verde archipelago. Part 1. Polyplacophora and Gastropoda. Germany: ConchBooks.","------2011. Moluscos y conchas marinas de Canarias. Germany: ConchBooks.","ROLAN, E. & FERNANDES, F. 1992. Aportaciones al conocimiento de la familia Turridae Swainson, 1840 (Mollusca, Gastropoda) en las islas de Sao Tome y Principe (Golfo Guinea). Nova Acta Cientifica Compostelana (Bioloxia) 3: 135-143.","ROLAN, E. & GORI, S. 2012. New species of neogastropods from the islands of the Gulf of Guinea, West Africa. Iberus 30: 53-66.","ROLAN, E. & HERNANDEZ, J.M. 2007. Three new species of Alvania (Gastropoda, Prosobranchia, Rissoidae) from Sao Tome Island (Gulf of Guinea, West Africa). Iberus 25: 9-18.","ROLAN, E. & RUBIO, F. 1990. Aportaciones al conocimiento sobre los micromoluscos de Africa occidental. 1. Tornidae de Sao Tome y Principe. Iberus 9: 181-186.","------1996. Un nuevo vitrinelido (Mollusca, Gastropoda, Vitrinellidae) de la isla de Sao Tome (Africa occidental). Iberus 14: 143-146.","RUBIO, F. & ROLAN, E. 1990. Aportaciones a los conocimientos sobre micromoluscos de Africa occidental. 2. Archaeogastropoda de Sao Tome y Principe. Iberus 9: 209-220.","RYALL, P., HORRO, J. & ROLAN, E. 2009. Two new species of Crassispira (Gastropoda, Conoidea) from West Africa with a taxonomic note on Crassispira tripter von Maltzan, 1883. Iberus 27: 131-139.","SABELLI, B. & SPADA, G. 1970. Chiton olivaceus Spengler, 1797. Schede Malacologiche del Mediterraneo Serie 87 Ea 01: 1-6.","SAITO, H. 1995. The chiton fauna of Onagawa Bay, Northeastern Honshu, Japan. Memoirs of the National Science Museum 28: 99-112.","------1997. Deep-sea chiton fauna of Suruga Bay (Mollusca: Polyplacophora) with descriptions of six new species. National Science Museum Monographs 12: 31-58.","------1998. The chitons (Mollusca: Polyplacophora) of the Goto Islands, West Coast of Kyushu, Japan. 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Ischnochiton cf. rissoi (Payraudeau, 1826) Figs 2I–K Chiton rissoi: Payraudeau 1826: 87, pl. 3, figs 4–5. Ischnochiton (I.) rissoi: Kaas & Van Belle 1990: 78, fig. 32; Dell’Angelo & Smriglio 1999: 100, pls 29–31, figs 40–48. Syntype:MNHN 6109 (not seen). Type locality: France, Bonifacio, Corse (41°23'10"N 09°09'31"E). Material examined: ST06: 1 specimen, length 1.3 mm (BD 107). Distribution: São Tomé Island. Comparison and remarks: The single available specimen shares with Ischnochiton rissoi a similar tegmental sculpture and dorsal girdle scales. I. rissoi varies considerably in size and sculpture (Carmona Zalvide & García 1999; Dell’Angelo & Smriglio 1999). The sculpture of the specimen examined is similar to the “forma 4” described by Carmona Zalvide and García (1999), from the Gibraltar area. The minute size of the specimen and the fact that the nominal species has so far not been reported from the African Atlantic coast, led us to the tentative identification. I. rissoi is typically Mediterranean, and recorded from the Atlantic only in the vicinity of Gibraltar. Records from the Canary Islands (Shuttleworth 1853; Bergenhayn 1931) as well as the Selvagens and Azores Islands (Bergenhayn 1931) require confirmation., Published as part of Dell'Angelo, Bruno, Schwabe, Enrico, Gori, Sandro, Sosso, Maurizio & Bonfitto, Antonio, 2014, Chitons (Mollusca, Polyplacophora) from São Tomé and Príncipe Islands, pp. 171-200 in African Invertebrates 55 (2) on page 176, DOI: 10.5281/zenodo.7680891, {"references":["PAYRAUDEAU, B. - C. 1826. Catalogue descriptif et methodique des annelides et des mollusques de l'Ile de Corse. Paris: Bechet.","CARMONA ZALVIDE, P. & GARCIA, F. J. G. 1999. Consideraciones morfologicas y taxonomicas sobre Ischnochiton (Ischnochiton) rissoi (Payraudeau, 1826) (Mollusca, Polyplacophora). Graellsia 55: 177 - 186.","SHUTTLEWORTH, R. J. 1853. Diagnosen neuer Mollusken. 4, Uber den Bau der Chitoniden, mit Aufzahlung der die Antillen und die Canarischen Inseln bewohnenden Arten. Mitteilungen der Naturforschenden Gesellschaft in Bern 286 - 291: 169 - 207.","BERGENHAYN, J. R. M. 1931. Beitrage zur Malakozoologie der Kanarischen Inseln. Die Loricaten. Arkiv for Zoologi, Stockholm 23 A: 1 - 38, 3 pls."]}

Craspedochiton foresti (Leloup, 1965) Figs 7A–T, 9P–S Notoplax foresti Leloup 1965: 155, text figs 1–3, pls 1–2; Kaas 1979: 873; Kaas 1986: 20 [as synonym of Notoplax (Spongiochiton) productus]; Kaas 1989: 109 [as synonym of Notoplax (Spongiochiton) producta]; Kaas & Van Belle 1998: 75 [as synonym of Notoplax (Spongiochiton) producta]. Holotype, MNHN 5922 (disarticulated). Type locality: Príncipe Island, Caroço Isl., 2–8 m, “Calypso” st. 88, 26.vi.1956. Craspedochiton foresti: Strack 1996: 132 (in the discussion of Craspedochiton productus). Material examined: ST03: 2 specimens, slightly curled, maximum length 16 mm (Figs 9P–S) (BD 114 A); ST03: 1 specimen, disarticulated and coated for SEM analysis (MZB 49763); ST03: 1 tail valve, length 3.5 mm (BD 114 B); ST04: 1 specimen, length 4.5 mm (BD 114 C); ST07: 5 specimens, slightly curled, maximum length 29 mm (BD 114 D); ST07: 1 specimen in alcohol, curled, length 15 mm (BD 114 E); ST07: 1 specimen in alcohol, strongly curled, length 10 mm (NSMT-Mo 78636); PR04: 5 specimens, slightly curled, maximum length 18 mm (BD 114 F); PR06: 1 specimen in alcohol, slightly curled, length 16 mm (ZSM Mol-20040209). Distribution: São Tomè and Príncipe Islands. Comparison and remarks: A detailed description of this species is given by Leloup (1965), pertaining to the genus Notoplax H. Adams, 1861. We confirm the assignment of the species to Craspedochiton, already reported by Strack (1996), based mainly on the wide expansion of the anterior girdle. The status of the relationship between the genera Notoplax and Craspedochiton was discussed by Gowlett-Holmes (1991), who redefined the genus Notoplax, and considered it to be restricted to Australia and New Zealand (but see under Notoplax sp.). We give only some information additional to the original description, based on the SEM observations. The tegmentum is covered by well separated pustules of irregular shape, from roundish/oval to squarish/rectangular, some of them coalesced, giving the impression of orientation in a radiating pattern from the jugum in the intermediate valves (Figs 7D, 7H) and in the antemucronal area of the tail valve.The pustules are elevated and of cylindrical shape (Fig. 7H), with up to 15 or more (Fig. 7G) microaesthetes, disposed without any apparent order. The microaesthetes are also present in the interpustular space. The radula is probably not useful for distinguishing between species of Craspedochiton (H. Saito pers. comm.). The radula of C. foresti (Fig. 7Q–T) is similar to that of C. productus illustrated in Saito (2004: figs 5E, F). The radula of C. foresti has minute granulations on the upper surface of the cusps (Fig. 7S–T), but it remains unclear whether this character has specific relevance. Some other species in different genera also show such granulation, e.g. Craspedoplax variabilis (H. Adams, 1864), and Leptoplax curvisetosa (Leloup, 1960) (Saito 2004: figs 4C, 8F). Craspedochiton. foresti was considered a synonym of C. productus (Carpenter in Pilsbry, 1892) by Kaas (1979: 873), who stated: “I received from the M.N.H.N. the holotype of Notoplax foresti Leloup, 1965 … The specimen originates from Ile Príncipe, Gulf of Biafra. Though it was disarticulated it appears from the shell plates and the preparations of the girdle, that it does not substantially differ from C. productus and must be regarded as another synonym of the latter, which extends the range of distribution considerably”. Subsequent authors (e.g. Kaas 1986, 1989; Kaas & Van Belle 1998) followed this decision. We re-examined both species and became aware that C. productus can easily be separated from C. foresti, mainly on the basis of the structure of the valves: intermediate and tail valves more oval in C. foresti, but trapezoidal in C. productus; larger and triangular jugal area in C. productus, narrow and rectangular in C. foresti; pustules more dense and more irregularly arranged in C. productus; wider apophyses in C. productus; slit formula 5 / 1 / 4 in C. productus, 5 / 1 / 7 in C. foresti, with short and irregular slits. The valves of a specimen of C. productus from South Africa (NSMT-Mo 72867) are illustrated for comparison (Figs 8A–F). The differences from C. productus have already been discussed by Leloup (1965: 159): “ N. productus se caractérise par des valves intermediaries proportionnellement plus élevées, au sinus plus large, aux lames d’insertion plus obliques et à bords latéraux du tegmentum plus obliques”. Thiele (1909: 33) described another congener from the Atlantic coast of Africa: Craspedochiton liberiensis Thiele, 1909. He examined a single specimen, which was 7 mm in length. Comparison with a 4.5 mm long specimen from ST04 indicates that Thiele had another species in hand. C. liberiensis exhibits at this size a more or less regular pattern of nearly round granules, which are elongated in our small specimen. Thiele (1909, pl. 4, fig. 30) illustrated an intermediate valve in which the arrangement of the granules are directed towards the indistinct jugal area. This is contrary to the pattern on our examined juvenile. The specimen’s jugal area is clearly wedge-shaped, well demarcated from the pleural area, and the granules are directed outwards. Whether C. liberiensis is a valid species or, as concluded by Kaas and Van Belle (1998), a synonym of C. productus, needs to be clarified by comparing a number of valves and specimens that are of similar size. Such comparisons are beyond the scope of the present study., Published as part of Dell'Angelo, Bruno, Schwabe, Enrico, Gori, Sandro, Sosso, Maurizio & Bonfitto, Antonio, 2014, Chitons (Mollusca, Polyplacophora) from São Tomé and Príncipe Islands, pp. 171-200 in African Invertebrates 55 (2) on pages 188-190, DOI: 10.5281/zenodo.7680891, {"references":["KAAS, P. & STRACK, H. L. 1986. Two new species of Lepidochitona Gray, 1821 (Polyplacophora: Ischnochitonidae) from Senegal and the Cabo Verde archipelago. Basteria 50: 79 - 86.","ADAMS, H. 1861. Descriptions of some new genera and species of shells from the collection of Hugh Cuming, Esq. Proceedings of the Zoological Society of London, 1861: 383 - 385.","PILSBRY, H. A. 1892 - 1894. Monograph of Polyplacophora. In: Tryon, G. W., Manual of conchology. Philadelphia: Academy of Natural Sciences, 14: 1 - 128, pls 1 - 30 (1892); i - xxxiv, 129 - 350, pls 31 - 68 (1893); 15: 1 - 64, pls 1 - 10 (1893); 65 - 133, pls 11 - 17 (1894)."]}

Genus Craspedochiton Shuttleworth, 1853 Craspedochiton: Shuttleworth 1853: 191. Type species: Chiton laqueatus Sowerby, 1841, by monotypy. For synonymy, see Gowlett-Holmes (2001). Distribution: Atlantic (African coast) and temperate and tropical Indo-Pacific. Eocene – Recent., Published as part of Dell'Angelo, Bruno, Schwabe, Enrico, Gori, Sandro, Sosso, Maurizio & Bonfitto, Antonio, 2014, Chitons (Mollusca, Polyplacophora) from São Tomé and Príncipe Islands, pp. 171-200 in African Invertebrates 55 (2) on page 188, DOI: 10.5281/zenodo.7680891, {"references":["SHUTTLEWORTH, R. J. 1853. Diagnosen neuer Mollusken. 4, Uber den Bau der Chitoniden, mit Aufzahlung der die Antillen und die Canarischen Inseln bewohnenden Arten. Mitteilungen der Naturforschenden Gesellschaft in Bern 286 - 291: 169 - 207."]}

Genus Acanthochitona Gray, 1821 Acanthochitona: Gray 1821: 234. Type species: Chiton fascicularis Linnaeus, 1767, by monotypy. For synonymy, see Gowlett-Holmes (2001). Distribution: Worldwide. Oligocene – Recent., Published as part of Dell'Angelo, Bruno, Schwabe, Enrico, Gori, Sandro, Sosso, Maurizio & Bonfitto, Antonio, 2014, Chitons (Mollusca, Polyplacophora) from São Tomé and Príncipe Islands, pp. 171-200 in African Invertebrates 55 (2) on page 187, DOI: 10.5281/zenodo.7680891, {"references":["GRAY, J. E. 1821. A natural arrangement of Mollusca, according to their internal structure. The London Medical Repository 15: 229 - 239."]}

Stenoplax hernandezi sp. n. Figs 3A–U, 9A–B Etymology: Named in honour of José María Hernández, malacologist from Gran Canaria, who passed away recently. He had frequently been a companion of Sandro Gori on trips and dives. Description: General shell shape: Animal small, up to 8 mm long, holotype 7.6 × 3.3 mm (Fig. 9A), elongate oval, much longer than twice the width, moderately elevated (dorsal elevation 0.31), back evenly rounded with convex side slopes. Colour of tegmentum uniformly light orange, somewhat variegated, with sandy brown streaks or flecks. Girdle of the same colour, with lighter bands present. Head valve semicircular (Fig. 3F), posterior margin widely V-shaped. Intermediate valves (Fig. 3I) with anterior margin slightly convex and sinuate at both sides, side margins rounded, posterior margin more or less straight, apices not evident, lateral areas little raised, poorly defined. Tail valve semicircular (Fig. 3L), length less than ⅔ of width, anterior margin straight and directed backwards laterally, mucro central, poorly evident, antemucronal slope slightly convex (Fig. 3M), postmucronal slope slightly concave just behind the mucro. Head valve, lateral areas of intermediate valves, and postmucronal area of tail valve sculptured with many close-set, irregularly undulate concentric grooves, better defined towards periphery (Fig. 3H); central area of intermediate valves and antemucronal area of tail valve smooth, some longitudinal grooves present but hardly visible. Articulamentum: Apophyses triangular, widely separated by a straight sinus (Fig. 3J), insertion plates short, slit formula 15 / 3 / 11, slit rays neatly indicated by distinct rays of pores, teeth sharp and not equidistant, eaves narrow. Girdle: Densely covered with small, rectangular, slightly bent, imbricating scales dorsally (Fig. 3S), rounded at the top, up to 55 μm long and 65 μm wide, with 14–15 narrow riblets, interstices wider. Compared to congeners, the scales are smaller, more rectangular and distally straight along a narrow strip at the margin, among which arise some conical, weakly longitudinally striated, pointed spines, up to 100 μm long (Fig. 3Q). Marginal fringe composed of small, longitudinally striated, pointed spines, ca 47 × 8 μm (Fig. 3P). Ventrally, the girdle is paved with radiating rows of small, cylindrical, smooth spicules (Fig. 3R), up to 60 μm long. Radula: Central tooth small and narrow, first lateral tooth elongate (Fig. 3T), with a narrow blade and a subapical wing, major lateral tooth (Fig. 3U) bears a bicuspid head with two equally strong denticles. Holotype: SÃO TOMÉ AND PRÍNCIPE: São Tomé, Minerio, ST 06, 7.6 × 3.3 mm, Fig. 9A (MZB 49751). Paratypes: Same data as holotype: 1 specimen, length 5.5 mm, slightly curled (BD 109); 1 specimen, length 7 mm, slightly curled (MNHN IM-2012-2701); 1 specimen, length 6.8 mm, disarticulated and coated for SEM analysis (MZB 49752); 1 specimen, length 4.9 mm, slightly curled (SG); 1 specimen, length 5.6 mm, slightly curled (ZISP 2197). Other paratypes: ST10, 1 specimen in alcohol, length 5.7 mm (ZSM Mol-20034146); ST10, 1 specimen in alcohol, length 5 mm (ZSM Mol-20034144); ST10, 1 specimen in alcohol, length 5.7 mm (ZSM Mol-20034150), disarticulated and coated for SEM analysis (Figs 3A–B); PR03, 1 specimen in alcohol, of a darker colour, Indian red with lighter streaks, length 6.8 mm (MHNS 100601). Other material examined: ST03: 1 specimen, length 8 mm, disarticulated for SEM analysis (Fig. 9B), and 76 valves (15 head, maximum width 3 mm, 12 intermediate, maximum width 3.4 mm, and 49 tail, maximum width 3 mm) (BD 110, ER); ST06: 2 specimens, maximum width 6.7 mm, and 11 valves (3 head, maximum width 3 mm, 5 intermediate, maximum width 3 mm, and 3 tail, maximum width 2.3 mm) (BD 111); ST08: 2 specimens, maximum length 5 mm (ZSM Mol-20034145). Distribution: São Tomé and Príncipe Islands. Comparison and remarks: This species was assigned to the genus Stenoplax mainly because of the elongate shape, with the length 2 to 3 times the width. On their own, not all characters of the new species match those of the genus Stenoplax. The lateral areas of Stenoplax species are generally rather elevated (Kaas & Van Belle 1987: 124; Vendrasco et al. 2012: 34), but are little raised and poorly defined in our species. However, the same characteristic is seen in other Stenoplax species, e.g. S. marcusi (Righi, 1971). About half of the approximately 22 living species of Stenoplax worldwide, occur in the temperate or tropical eastern Pacific, but a few species are found in the Caribbean, and two species are known from Brazil, namely Stenoplax kempfi (Righi, 1971) and S. marcusi (Righi, 1971). The finding of Stenoplax hernandezi sp. n. on the Atlantic African coast greatly extends the distribution of this genus. Stenoplax kempfi differs from the present species mainly in respect of the different sculpture (radial riblets on the head valve, lateral areas of intermediate valves, and postmucronal area of tail valve, longitudinal riblets on the central area of intermediate valves, and antemucronal area of tail valve, vs. concentric undulate grooves and no riblets in the new species); the greater dimensions (maximum length from 44 to 120 mm vs. 8mm); and the dorsal girdle formations (always elongate scales/spicules, not rectangular scales as in the new species). Stenoplax marcusi, originally placed in Ischnochiton, and later attributed to Stenoplax by Kaas and Van Belle (1994) following study of the type material, has a tegmental sculpture more similar to that of S. hernandezi sp. n., a similar colour, and it is of comparable size (maximum length 11.8 vs. 8 mm). It differs because of the higher elevation (dorsal elevation 0.47 vs. 0.31), the number of intermediate valve slits (1 vs. 3), and the different girdle formations (see Righi 1971; Kaas & Van Belle 1994). Only a single species of Stenoplax is known from the Indian Ocean, namely S. madagassica (Thiele, 1917) from Madagascar. This species differs from the present species in having greater dimensions (up to 65 mm long vs. 8 mm), being more highly elevated (dorsal elevation 0.42 vs. 0.31), having different dorsal girdle scales (elongate and up to 145 μm long with interspersed whitish ringshaft-needles vs. rectangular up to 55 × 65 μm), and in respect of the geographical distribution (Madagascar vs. São Tomé). Stenoplax hernandezi sp. n. is generally similar to some of the small Ischnochiton species reported from West African coasts (i.e. I. goreensis, I. paessleri, and I. nicklesi), but they all have a tegmental sculpture that is mainly smooth or finely granulose., Published as part of Dell'Angelo, Bruno, Schwabe, Enrico, Gori, Sandro, Sosso, Maurizio & Bonfitto, Antonio, 2014, Chitons (Mollusca, Polyplacophora) from São Tomé and Príncipe Islands, pp. 171-200 in African Invertebrates 55 (2) on pages 178-181, DOI: 10.5281/zenodo.7680891, {"references":["VENDRASCO, M. J., EERNISSE, D. J., POWELL, C. L. II & FERNANDEZ, C. Z. 2012. Polyplacophora (Mollusca) from the San Diego formation: a remarkable assemblage of fossil chitons from the Pliocene of southern California. Contributions in Science (Natural History Museum of Los Angeles) 520: 15 - 72.","RIGHI, G. 1971. Moluscos poliplacoforos do Brazil. Papeis Avulsos de Zoologia 24: 123 - 146."]}

Stenoplax hernandezi sp. n. Figs 3A–U, 9A–B Etymology: Named in honour of José María Hernández, malacologist from Gran Canaria, who passed away recently. He had frequently been a companion of Sandro Gori on trips and dives. Description: General shell shape: Animal small, up to 8 mm long, holotype 7.6 × 3.3 mm (Fig. 9A), elongate oval, much longer than twice the width, moderately elevated (dorsal elevation 0.31), back evenly rounded with convex side slopes. Colour of tegmentum uniformly light orange, somewhat variegated, with sandy brown streaks or flecks. Girdle of the same colour, with lighter bands present. Head valve semicircular (Fig. 3F), posterior margin widely V-shaped. Intermediate valves (Fig. 3I) with anterior margin slightly convex and sinuate at both sides, side margins rounded, posterior margin more or less straight, apices not evident, lateral areas little raised, poorly defined. Tail valve semicircular (Fig. 3L), length less than ⅔ of width, anterior margin straight and directed backwards laterally, mucro central, poorly evident, antemucronal slope slightly convex (Fig. 3M), postmucronal slope slightly concave just behind the mucro. Head valve, lateral areas of intermediate valves, and postmucronal area of tail valve sculptured with many close-set, irregularly undulate concentric grooves, better defined towards periphery (Fig. 3H); central area of intermediate valves and antemucronal area of tail valve smooth, some longitudinal grooves present but hardly visible. Articulamentum: Apophyses triangular, widely separated by a straight sinus (Fig. 3J), insertion plates short, slit formula 15 / 3 / 11, slit rays neatly indicated by distinct rays of pores, teeth sharp and not equidistant, eaves narrow. Girdle: Densely covered with small, rectangular, slightly bent, imbricating scales dorsally (Fig. 3S), rounded at the top, up to 55 μm long and 65 μm wide, with 14–15 narrow riblets, interstices wider. Compared to congeners, the scales are smaller, more rectangular and distally straight along a narrow strip at the margin, among which arise some conical, weakly longitudinally striated, pointed spines, up to 100 μm long (Fig. 3Q). Marginal fringe composed of small, longitudinally striated, pointed spines, ca 47 × 8 μm (Fig. 3P). Ventrally, the girdle is paved with radiating rows of small, cylindrical, smooth spicules (Fig. 3R), up to 60 μm long. Radula: Central tooth small and narrow, first lateral tooth elongate (Fig. 3T), with a narrow blade and a subapical wing, major lateral tooth (Fig. 3U) bears a bicuspid head with two equally strong denticles. Holotype: SÃO TOMÉ AND PRÍNCIPE: São Tomé, Minerio, ST 06, 7.6 × 3.3 mm, Fig. 9A (MZB 49751). Paratypes: Same data as holotype: 1 specimen, length 5.5 mm, slightly curled (BD 109); 1 specimen, length 7 mm, slightly curled (MNHN IM-2012-2701); 1 specimen, length 6.8 mm, disarticulated and coated for SEM analysis (MZB 49752); 1 specimen, length 4.9 mm, slightly curled (SG); 1 specimen, length 5.6 mm, slightly curled (ZISP 2197). Other paratypes: ST10, 1 specimen in alcohol, length 5.7 mm (ZSM Mol-20034146); ST10, 1 specimen in alcohol, length 5 mm (ZSM Mol-20034144); ST10, 1 specimen in alcohol, length 5.7 mm (ZSM Mol-20034150), disarticulated and coated for SEM analysis (Figs 3A–B); PR03, 1 specimen in alcohol, of a darker colour, Indian red with lighter streaks, length 6.8 mm (MHNS 100601). Other material examined: ST03: 1 specimen, length 8 mm, disarticulated for SEM analysis (Fig. 9B), and 76 valves (15 head, maximum width 3 mm, 12 intermediate, maximum width 3.4 mm, and 49 tail, maximum width 3 mm) (BD 110, ER); ST06: 2 specimens, maximum width 6.7 mm, and 11 valves (3 head, maximum width 3 mm, 5 intermediate, maximum width 3 mm, and 3 tail, maximum width 2.3 mm) (BD 111); ST08: 2 specimens, maximum length 5 mm (ZSM Mol-20034145). Distribution: São Tomé and Príncipe Islands. Comparison and remarks: This species was assigned to the genus Stenoplax mainly because of the elongate shape, with the length 2 to 3 times the width. On their own, not all characters of the new species match those of the genus Stenoplax. The lateral areas of Stenoplax species are generally rather elevated (Kaas & Van Belle 1987: 124; Vendrasco et al. 2012: 34), but are little raised and poorly defined in our species. However, the same characteristic is seen in other Stenoplax species, e.g. S. marcusi (Righi, 1971). About half of the approximately 22 living species of Stenoplax worldwide, occur in the temperate or tropical eastern Pacific, but a few species are found in the Caribbean, and two species are known from Brazil, namely Stenoplax kempfi (Righi, 1971) and S. marcusi (Righi, 1971). The finding of Stenoplax hernandezi sp. n. on the Atlantic African coast greatly extends the distribution of this genus. Stenoplax kempfi differs from the present species mainly in respect of the different sculpture (radial riblets on the head valve, lateral areas of intermediate valves, and postmucronal area of tail valve, longitudinal riblets on the central area of intermediate valves, and antemucronal area of tail valve, vs. concentric undulate grooves and no riblets in the new species); the greater dimensions (maximum length from 44 to 120 mm vs. 8mm); and the dorsal girdle formations (always elongate scales/spicules, not rectangular scales as in the new species). Stenoplax marcusi, originally placed in Ischnochiton, and later attributed to Stenoplax by Kaas and Van Belle (1994) following study of the type material, has a tegmental sculpture more similar to that of S. hernandezi sp. n., a similar colour, and it is of comparable size (maximum length 11.8 vs. 8 mm). It differs because of the higher elevation (dorsal elevation 0.47 vs. 0.31), the number of intermediate valve slits (1 vs. 3), and the different girdle formations (see Righi 1971; Kaas & Van Belle 1994). Only a single species of Stenoplax is known from the Indian Ocean, namely S. madagassica (Thiele, 1917) from Madagascar. This species differs from the present species in having greater dimensions (up to 65 mm long vs. 8 mm), being more highly elevated (dorsal elevation 0.42 vs. 0.31), having different dorsal girdle scales (elongate and up to 145 μm long with interspersed whitish ringshaft-needles vs. rectangular up to 55 × 65 μm), and in respect of the geographical distribution (Madagascar vs. São Tomé). Stenoplax hernandezi sp. n. is generally similar to some of the small Ischnochiton species reported from West African coasts (i.e. I. goreensis, I. paessleri, and I. nicklesi), but they all have a tegmental sculpture that is mainly smooth or finely granulose.

Chaetopleura caboverdensis (Kaas & Strack, 1986) Figs 4A–L Lepidochitona caboverdensis: Kaas & Strack 1986: 79, figs 1–15; Kaas & Van Belle 1987: 31, fig. 14; Kaas 1991: 91; Slieker 2000: 28, fig. 17; Ardovini & Cossignani 2004: 18. Holotype: MNHN, 5.8 × 3.2 mm, preserved dry. Paratypes: Many specimens in several institutions (see Kaas & Strack 1986). Type locality: Senegal, Dakar. Chaetopleura caboverdensis: Rolán 2005: 27, fig. 2; Sirenko 2006: fig. 1I. Material examined: ST03: 21 valves (4 head, maximum width 2.5 mm, 16 intermediate, maximum width 3 mm, and 1 tail, width 1.5 mm) (ER); ST11: 21 valves (4 head, maximum width 2.3 mm, 15 intermediate, maximum width 3 mm, and 2 tail, maximum width 2.2 mm) (BD 112A); PR05: 1 intermediate valve, width 2.3 mm (BD 112B); PR07: 2 intermediate valves, maximum width 2.2 mm (BD 112C); CAPE VERDE: Cape Verde Archipelago, São Vicente, Praia da Matiota: 1 specimen (BD 2919). Distribution: Cape Verde Archipelago, Senegal, and São Tomé and Príncipe Islands. Comparison and remarks: This species was originally placed in the genus Lepidochitona, mainly due to the morphology of the ventral girdle scales and to the characters of the articulamentum, but was later considered as belonging to Chaetopleura (see Rolán 2005; Sirenko 2006). The available material was only separate valves, well defined by the subcarinate and slightly beaked intermediate valves, and by the characteristic microsculpture: rounded and elevated granules with a central macroaesthete on the top (Figs 4C, 4I). The microsculpture of a specimen of Chaetopleura caboverdensis from the Cape Verde Archipelago (Figs 4K, 4L) is presented for comparison. This is the first report of this species for the São Tomé and Príncipe Islands., Published as part of Dell'Angelo, Bruno, Schwabe, Enrico, Gori, Sandro, Sosso, Maurizio & Bonfitto, Antonio, 2014, Chitons (Mollusca, Polyplacophora) from São Tomé and Príncipe Islands, pp. 171-200 in African Invertebrates 55 (2) on page 181, DOI: 10.5281/zenodo.7680891, {"references":["KAAS, P. & STRACK, H. L. 1986. Two new species of Lepidochitona Gray, 1821 (Polyplacophora: Ischnochitonidae) from Senegal and the Cabo Verde archipelago. Basteria 50: 79 - 86.","SLIEKER, F. J. A. 2000. Chitons of the world. An illustrated synopsis of recent Polyplacophora. Ancona: L'Informatore Piceno.","ARDOVINI, R. & COSSIGNANI, T. 2004. West African seashells (including Azores, Madeira and Canary Is.). Ancona: L'Informatore Piceno.","ROLAN, E. 2005. Malacological fauna from the Cape Verde archipelago. Part 1. Polyplacophora and Gastropoda. Germany: ConchBooks.","SIRENKO, B. 2006. New outlook on the system of chitons (Mollusca: Polyplacophora). Venus 65: 27 - 49."]}

Acanthochitona crinita (Pennant, 1777) Figs 6G–L, 9O Chiton crinitus: Pennant 1777: 71, pl. 36, figs 1, A1. Neotype designated and figured by Kaas (1985: 591, fig. 27), RSMNH 1978.052.02601 (not seen). Type locality: Hebrides Islands, Monach Island, North Uist, U.K. (57°31.5'N: 07°38.5'W). Acanthochitona crinita: Kaas 1985: 588, figs 7–50 (chresonymy and synonymy); Dell’Angelo & Smriglio 1999: 198, pls 66–68, figs 124–130; Bonfitto et al. 2011: 173, figs 2, 4B, 6B. Material examined: ST03: 103 valves, 12 head (maximum width 3 mm), 82 intermediate (maximum width 5 mm), and 9 tail (maximum width 3.5 mm) (BD 113 A); ST06: 3 specimens, maximum length 6.5 mm (Fig. 9O), and 11 valves, 10 intermediate (maximum width 2.5 mm), and 1 tail (width 1.8 mm) (BD 113 B); ST11: 9 intermediate valves, maximum width 2.5 mm (ER); PR07: 1 intermediate valve, width 1.7 mm (BD 113 C). Distribution: Mediterranean Sea, the Atlantic coast of Europe (as far north as Norway), and the northern West African coast, plus São Tomé and Príncipe Islands. Comparison and remarks: Acanthochitona crinita appears to be very variable, in its tegmental sculpture, dorsal elevation, the shape of the valves, and in the colour of the tegmentum (Leloup 1968 b; Kaas 1985; Dell’Angelo & Smriglio 1999). Also, the shape of the granules is variable, being round to slightly oval, to a more or less elongate drop (Kaas 1985; Bonfitto et al. 2011), but they are always widely separated, not as densely orientated as in A. fascicularis. The granules have a flat or slightly concave surface, with a central macroaesthete and 8–16 microaesthetes irregularly arranged around it. Kaas (1985) examined the type material of the five northwest African species of Acanthochitona described by de Rochebrune, (1881–1884) (formerly studied by Thiele 1909), i.e. A. dakariensis, A. adansoni, A. bouvieri, A. joallesi, and A. stercorarius. All of these were synonymized with A. crinita by Leloup (1968 b: 68). Kaas concluded that only A. joallesi is a valid species, whereas A. adansoni and A. bouvieri are synonymous with A. crinita (Pennant, 1777). A. dakariensis and A. stercorarius are considered nomina dubia. Leloup’s (1941) Acanthochitona subrubicunda from Cape Verde Islands may be separated by its broad, wedge-shaped jugal area., Published as part of Dell'Angelo, Bruno, Schwabe, Enrico, Gori, Sandro, Sosso, Maurizio & Bonfitto, Antonio, 2014, Chitons (Mollusca, Polyplacophora) from São Tomé and Príncipe Islands, pp. 171-200 in African Invertebrates 55 (2) on page 188, DOI: 10.5281/zenodo.7680891, {"references":["PENNANT, T. 1777. British Zoology. Crustacea. Mollusca. Testacea. London: B. White.","BONFITTO, A., DELL' ANGELO, B., EVANGELISTI, F. & SABELLI, B. 2011. The genus Acanthochitona (Mollusca: Polyplacophora) in the Mediterranean Sea: morphological and molecular data. Scientia Marina 75: 171 - 180.","LELOUP, E. 1941. A propos de quelques acanthochitons peu connus ou nouveaux II. Region Atlantique. Bulletin du Musee Royal d'Histoire Naturelle de Belgique 17 (43): 1 - 15."]}

Genus Notoplax H. Adams, 1861 Notoplax: H. Adams 1861: 385. Type species: Cryptoplax (Notoplax) speciosa H. Adams, 1861, by monotypy. For synonymy, see Gowlett-Holmes (1991). Distribution: Restricted to Australia and New Zealand (Gowlett-Holmes 1991). Oligocene – Recent., Published as part of Dell'Angelo, Bruno, Schwabe, Enrico, Gori, Sandro, Sosso, Maurizio & Bonfitto, Antonio, 2014, Chitons (Mollusca, Polyplacophora) from São Tomé and Príncipe Islands, pp. 171-200 in African Invertebrates 55 (2) on page 191, DOI: 10.5281/zenodo.7680891, {"references":["ADAMS, H. 1861. Descriptions of some new genera and species of shells from the collection of Hugh Cuming, Esq. Proceedings of the Zoological Society of London, 1861: 383 - 385."]}

Genus Stenoplax Dall, 1879 Stenoplax: Dall 1879: 296. Type species: Chiton limaciformis Sowerby, 1832, by original designation. For synonymy, see Kaas & Van Belle (1987). Diagnosis: Of small to large size, elongate, the length 2 to 3 times the width, tail valve relatively large, depressed, mucro subcentral and inconspicuous, slit formula many /1 or more /many, girdle decorated with minute to large, more or less elongate scales, or with stout, bent, striated spines (Kaas & Van Belle 1987). Distribution: East Pacific Ocean (from Canada to Peru), Indo-Pacific Ocean (from Japan to India), Indian Ocean (Madagascar), West Atlantic Ocean (from Florida to Brazil). Eocene – Recent. Remarks: The genus Stenoplax is divided in two subgenera, Stenoplax s.s. (having the insertion plates of intermediate valves single-slitted), and Stenoradsia Dall, 1879 (having the insertion plates of intermediate valves multi-slitted). This character does not reflect phylogenetic affinity amongst the scattered, non-eastern Pacific species (Eernisse pers. comm.), so we do not consider an attribution at subgeneric level.