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Sterrenburg, Frithjof A. S., Haan, Myriam De, Herwig, Wulf E., Hargraves, Paul E. (2014): Typification and taxonomy of Gyrosigma tenuissimum (W. Sm.) J.W. Griffith & Henfr., comparison with Gyrosigma coelophilum N. Okamoto & Nagumo and description of two new taxa: Gyrosigma tenuissimum var. gundulae var. nov. and Gyrosigma baculum sp. nov. (Pleurosigmataceae, Bacillariophyta). Phytotaxa 172 (2): 71-80, DOI: 10.11646/phytotaxa.172.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.172.2.2

Gyrosigma baculum Herwig & Sterrenburg, sp. nov. (Figs 24–27) Valve linear, 82–92 µm long, 5.5–6.0 µ wide, transverse striae circa 18–19 in 10 µm, longitudinal striae circa 35–37 in 10 µm, raphe sternum staff-shaped in its apical portion. Type:— ITALY, Cala Gonone, Sardinia (BRM ZU 8 /35!, holotype, coordinates 7.4 East, 4.6 South = Fig. 24; Fig 25 is another specimen from the same slide, isotype; collection Herwig, isotype; collection Sterrenburg # 712, isotype). Valves very delicate, 82–92 µm long, 5.5–6.0 µm wide, practically parallel-sided and straight for most of their length, becoming sigmoid near acute apex. Raphe sternum straight except near apices, where it first curves to dorsal side and then recurves on a strongly eccentric and sigmoid course. Striation (Fig. 26): transverse striae circa 18–19 in 10 µm, longitudinal striae circa 35–37 in 10 µm, becoming irregular at the apices (Fig. 27). No hyaline central area visible, central raphe node minute and elongated. Etymology: —The specific epithet baculum (“staff”) is chosen to describe the typical reversed curvature of the raphe sternum at the apices. Habitat:—Littoral-marine, benthic. Distribution:— Type locality only. Observations:— Gyrosigma baculum differs from G. tenuissimum in two independent characters: the different course of the raphe sternum and stria density. Gyrosigma baculum somewhat resembles Gyrosigma uncinatum Ricard (1975: 209, fig. 3) in valve contour and raphe sternum course but G. uncinatum has much coarser (15 in 10 µm) transverse striae, a value incompatible with the stria density of G. baculum. No type specimens for Gyrosigma uncinatum have been deposited in PC. No specimens have been isolated for G. baculum for SEM examination as it is very rare in the type material, but the LM findings of raphe sternum course and stria densities already permit separation from the described species., Published as part of Sterrenburg, Frithjof A. S., Haan, Myriam De, Herwig, Wulf E. & Hargraves, Paul E., 2014, Typification and taxonomy of Gyrosigma tenuissimum (W. Sm.) J. W. Griffith & Henfr., comparison with Gyrosigma coelophilum N. Okamoto & Nagumo and description of two new taxa: Gyrosigma tenuissimum var. gundulae var. nov. and Gyrosigma baculum sp. nov. (Pleurosigmataceae, Bacillariophyta), pp. 71-80 in Phytotaxa 172 (2) on page 76, DOI: 10.11646/phytotaxa.172.2.2, http://zenodo.org/record/5142351, {"references":["Ricard, M. (1975) Quelques diatomees nouvelles de Tahiti decrites en microscopie photonique et electronique a balayage. Bulletin du Museum National d'Histoire Naturelle, Botanique, 3 e ser., no 326, 23: 201 - 229."]}

Luticola doliiformis Kopalov�� & Van de Vijver, sp. nov. (Figs 14���28) Valvae lanceolatae marginibus convexis, apicibusque capitatis. Longitudo 17���22 ��m, latitudo 7���8 ��m. Area axialis lata, lanceolata, clare dilatata in aream centralem, leviterque dilatata in apices. Area centralis formans staurum rectangularem, marginatum serie una areolarum rotundatatrum. Stigma solitaria rotundata prope marginem valvae adest. Raphe filiformis, clare curvata, terminationibus proximalibus unilateraliter deflexis, fissurisque distalibus curtis, rectis. Striae transapicales radiatae in centro valvae, convergentes ad apices, 18���20 in 10 ��m. Areolae parvae, semper rotundae, 2-3 per striam. Type: ��� ANTARCTICA. James Ross Island, Ulu Peninsula, Lachman Crags, sample D07, leg. L. Nedbalov��, coll. date 27/01/2008, slide no. BR-4250 (holotype BR, Fig. 20 is the encircled holotype specimen), slide PLP-195 (isotype University of Antwerp, Belgium), BRM-ZU8/07 (isotype BRM). Valves lanceolate with convex margins and capitate apices (Figs 14���24). Valve length 17���22 ��m, valve width 7���8 ��m (n=15). Axial area broad, lanceolate, clearly widening towards central area, only slightly widening towards apices (Fig. 25). Central area forming a broad, rectangular stauros, bordered by one series of small, rounded areolae (Fig. 27). One small, solitary, rounded stigma present, close to valve margin (Fig. 27). External raphe branches clearly curved, with weakly unilaterally deflected, simple proximal endings away from stigma (Fig. 27). Distal raphe fissures very short, straight (Fig. 28). Transapical striae radiate near valve centre becoming convergent towards apices, 18���20 in 10 ��m (Fig. 25). Striae composed of 2-3 small, always rounded areolae (Fig. 25). Internal structure hardly visible since only one valve was found (Fig. 26). Clearly developed stauros present. Detail of internal stigma opening obscured by debris. Proximal raphe endings terminating on edge of stauros. Habitat, Ecology and Distribution:��� Luticola doliiformis was found in small cracks on wet soil on the table mountain Lachman Crags close to the glacier front. The sample was dominated by Luticola cohnii, Hantzschia amphioxys (Ehrenberg 1843: 413) Grunow (in Cleve & Grunow 1880: 103) and several unidentified species of Diadesmis. Etymology: ��� This specific epithet doliiformis refers to its close resemblance to L. dolia (- formis: Latin for ���resembling���). Observations: ��� The James Ross Island (JRI) specimen of Luticola doliiformis bears a strong resemblance to L. dolia, a taxon described from the McMurdo Dry Valleys on the Antarctic Continent (Esposito et al. 2008). The valve dimensions do not permit discrimination between the two taxa but there are other important differences. Unfortunately, in the original description of Esposito et al. (2008), the ultrastructure of the valves and girdle could not be examined as specimens were rare in the samples. Therefore, isotype material (INSTAAR Collection slide 532, isotype slide for Luticola dolia Spaulding & Esposito, Esposito et al. 2008: 1385) was re-examined using SEM and two valves were found showing some of the morphological features enabling separation between L. dolia and L. doliiformis (Figs 29���34). Based on the description in Esposito et al. (2008) and our observations of the isotype material, several differences can be noted. The distal raphe fissures in the JRI population are very short contrary to L. dolia where slightly elongated fissures were noted (Fig. 33). The valve apices in L. dolia are usually much narrower than in L. doliiformis that have normally broadly rounded, enlarged apices (Figs 29���31). The shape and size of the areolae also differs with transapically elongated, larger areolae in L. dolia, whereas L. doliiformis has small, always rounded areolae (Figs 32, 33). Moreover, the number of striae in 10 ��m is higher in the JRI population contrary to that stated in the original description (18���20 vs 14���18). Although the external stigma opening could not be observed in the isotype material, it is clear that, based on the LM and the internal SEM views of L. dolia (Fig. 34), the stigma opening is positioned more to the valve middle whereas in L. doliiformis, the stigma opening is closer to the valve margin (Fig. 25). Based on these differences, separation of these taxa can be made., Published as part of Kopalov��, Kate��ina, Nedbalov��, Linda, Haan, Myriam De & Vijver, Bart Van De, 2011, Description of five new species of the diatom genus Luticola (Bacillariophyta, Diadesmidaceae) found in lakes of James Ross Island (Maritime Antarctic Region), pp. 44-60 in Phytotaxa 27 on pages 49-50, DOI: 10.11646/phytotaxa.27.1.5, http://zenodo.org/record/4894204, {"references":["Ehrenberg, C. G. (1843) Verbreitung und Einfluss des mikroskopischen Lebens in Sud-und Nord-Amerika. Abhandlungen der Koniglichen Akademie der Wissenschaften zu Berlin 1841: 291 - 445.","Cleve, P. T. & Grunow, A. (1880) Beitrage zur Kenntniss der Arctischen Diatomeen. Kongliga Svenska-Vetenskaps Akademiens Handlingar 17 (2): 1 - 121.","Esposito, R. M. M., Spaulding, S. A., McKnight, D. M., Van de Vijver, B., Kopalova, K., Lubinski, D., Hall, B. & Whittaker, T. (2008) Inland diatoms from the McMurdo Dry Valleys and James Ross Island, Antarctica. Botany 86: 1378 - 1392."]}

Luticola desmetii Kopalov�� & Van de Vijver, sp. nov. (Figs 2���13) Valvae rhombicae at rhombicae-elloticae marginibus distincte convexis, apicibusque protractis, rostratis. Longitudo 22��� 42.5 ��m, latitudo 11.3���16.8 ��m. Area axialis angustissima, paene linearis ad linearis-lanceolata, leviter dilatata in aream centralem. Sternum lineare adest marginatum depressionibus longitudinalibus. Area centralis irregularis, formans staurum rectangularem asymmetricum, marginatum serie una areolarum rotundatarum ad leviter transapicaliter elongatarum. Stigma solitaria magna rimiformis inter mediam partem valvae marginesque. Depressiones plures in area centrali, visibiles in microscopio photonico. Raphe filiformis, recta, terminationibus proximalibus indistinctis, fissurisque distalibus elongatis, deflexis. Striae transapicales radiatae in centro valvae, fortiter radiatae ad apices, 12���16 in 10 ��m. Type:��� ANTARCTICA. James Ross Island, Ulu Peninsula, Blue-Green Lake, sample D51, leg. L. Nedbalov��, coll. date 27/01/2009, slide no. BR-4241 (holotype BR, Fig. 7 is the encircled holotype specimen), slide PLP-189 (isotype University of Antwerp, Belgium), BRM-ZU8/06 (isotype BRM). Valves rhombic to rhombic-elliptical with inflated, distinctly convex margins (Figs 2���8). Apices typically protracted, rostrate. Valve length 22���42.5 ��m, valve width 11.3���16.8 ��m (n=37). Axial area quite narrow, almost linear to linear-lanceolate, slightly widening towards the central area, formed by a raised, almost straight, linear sternum; bordered by longitudinal depressions (Fig. 9). Central area irregular, forming a rectangular, asymmetrical stauros, bordered by one series of rounded to very weakly transapically elongated areolae. One large, slit-like isolated stigma present, located halfway between valve margin and valve centre (Figs 9, 11). Multiple irregular, shallow depressions present in central area, visible in LM (Figs 9, 11). External raphe branches usually straight, with inconspicuous straight proximal raphe endings (Figs 9, 11). Distal raphe endings elongated, deflected towards stigma-bearing side (Figs 9, 12). Transapical striae radiate near valve centre, becoming strongly radiate towards poles, 12���16 in 10 �� m. Pattern of areolae rather irregular. Striae usually composed of 2���3 small, rounded areolae and one slit-like areola close to valve margin (Fig. 9). Towards apices, striae composed of 1���2 strictly rounded areolae (Fig. 12). Internally, poroids of valve face occluded by hymenes (Figs 10, 13). Internal expression of stigma absent (Fig. 13). Distinct stauros visible (Fig. 13). Longitudinal canal covered by siliceous outgrowth (Figs 10, 13). Internal proximal raphe endings terminate on edge of stauros (Fig. 13). Distal raphe endings terminate on small helictoglossae (Fig. 10). Habitat, Ecology and Distribution:��� To date, L. desmetii has been found only in one small kettle lake (Blue-Green Lake) on James Ross Island close to the Whisky Glacier. The largest population was found in an epilithon sample. The lake had a pH of 7.8, a low specific conductance (91 ��S/cm) and was relatively species rich with 32 species observed, dominated by Nitzschia taxa belonging to the complex around Nitzschia perminuta (Grunow in Van Heurck 1881: pl.68. Fig. 31) Peragallo (1903: 672) and Psammothidium metakryophilum (Lange-Bertalot & Schmidt in Schmidt et al. 1990: 64) Sabbe (in Sabbe et al. 2003: 242). A record from the South Shetland Islands (H��kansson & Jones 1994) has not be verified. Etymology:��� Luticola desmetii is named after our dear friend and colleague Prof. Dr. Willem De Smet (University of Antwerp, Belgium) in honour of his Arctic and Antarctic limnological work. Observations: ��� At present, no Luticola taxa have a similar valve shape to L. desmetii. Luticola higleri and L. katkae Van de Vijver & Zidarova (in Van de Vijver, Zidarova & de Haan 2011: 143) have a similar irregular pattern of longitudinal depressions, raised sternum and shallow depressions in the axial and central area (Van de Vijver et al. 2006, 2011). However, both taxa have a different valve outline with clearly capitate apices (L. katkae) and broadly rounded valves (L. katkae and L. higleri). Moreover, L. higleri shows a distinct marginal rim on the valve face/mantle margin, which is absent in L. desmetii. Both have short distal raphe fissures in contrast to the elongated, deflected distal raphe endings in L. desmetii. At present, no taxon of Luticola has a similar valve outline. Luticola heufleriana (Grunow 1863: 155) D.G.Mann (in Round, Crawford & Mann 1990: 671) has weakly rhombic valves with clearly capitate apices, whereas L. lagerheimii (Cleve 1894: Taf. 7:11) D.G.Mann (in Round, Crawford & Mann 1990: 671) has a comparable outline but forms long chains, has deflected proximal raphe endings and short marginal spines. Bj��rck et al. (1996) reported L. heufleriana from sediment cores taken in three lakes on Ulu Peninsula, close to Blue-Green Lake. Although this record could not be verified, due to the lack of samples and illustrations, it is highly likely that this taxon should be attributed to L. desmetii., Published as part of Kopalov��, Kate��ina, Nedbalov��, Linda, Haan, Myriam De & Vijver, Bart Van De, 2011, Description of five new species of the diatom genus Luticola (Bacillariophyta, Diadesmidaceae) found in lakes of James Ross Island (Maritime Antarctic Region), pp. 44-60 in Phytotaxa 27 on pages 47-49, DOI: 10.11646/phytotaxa.27.1.5, http://zenodo.org/record/4894204, {"references":["Van Heurck, H. (1881) Synopsis des Diatomees de Belgique. Atlas. Ducaju & Cie., Anvers. pls 31 - 77.","Peragallo, M. (1903) Le Catalogue General des Diatomees. Clermont-Ferrand. 2: 472 - 973.","Schmidt, R., Mausbacher, R. and Muller, J. (1990) Holocene diatom flora and stratigraphy from sediment cores of two Antarctic lakes (King George Island). Journal of Paleolimnology 3 (1): 55 - 74.","Sabbe, K., Verleyen, E., Hodgson, D. A., Vanhoutte, K. and Vyverman, W. (2003) Benthic diatom flora of freshwater and saline lakes in the Larsemann Hills and Rauer Islands, East Antarctica. Antarctic Science 15: 227 - 248.","Hakansson, H. & Jones, V. J. (1994) The compiled freshwater diatom taxa list for the maritime region of the South Shetland and South Orkney Islands. In: Hamilton, P. B. (ed.), Proceedings of the Fourth Arctic-Antarctic Diatom Symposium Workshop, Canadian Technical report of Fisheries and Aquatic Sciences 157: 77 - 83.","Van de Vijver, B., Zidarova, R. & de Haan, M. (2011) Four new Luticola taxa (Bacillariophyta) from the South Shetland Islands and James Ross Island (Maritime Antarctic Region). Nova Hedwigia 92: 137 - 158.","Van de Vijver, B., Van Dam, H. & Beyens, L. (2006) Luticola higleri sp. nov. A new diatom species from King George Island (South Shetland Island, Antarctica). Nova Hedwigia 83: 69 - 79.","Grunow, A. (1863) Ueber einige neue und ungenugend bekannte Arten und Gattungen von Diatomaceen. Verhandlungen der Kaiserlich-Koniglichen Zoologisch-Botanischen Gesellschaft in Wien 13: 137 - 162.","Round, F. E., Crawford, R. M. & Mann, D. G. (1990) The diatoms: Biology and Morphology of the genera. Cambridge, Cambridge University Press, 747 pp.","Cleve, P. T. (1894) Synopsis of the Naviculoid Diatoms, Part I. Kongliga Svenska-Vetenskaps Akademiens Handlingar 26: 1 - 194.","Bjorck, S., Olson, S., Ellis-Evans, C., Hakansson, H., Humlum, O. & Manuel de Lirio, J. (1996) Late Holocene palaeoclimatic records from lake sediments on James Ross Island, Antarctica. Palaeogeography, Palaeoclimatology, Palaeoecology 121: 195 - 220."]}

Luticola tomsui Kopalov��, sp. nov. (Figs 73���87) Valvae lineares ad lineares-ellipticae apicibus late rotundatis. Margines clare sed asymmetrice constrictae in media parte valvae. Longitudo 18.5���23 ��m, latitudo 6.5���8.1 ��m. Area axialis lata, lanceolata, clare dilatata ad apices areamque centralem. Area centralis formans staurum rectangularem ad paene ellipticum, marginatum serie una areolarum parvarum rotundatarum ad leviter transapicaliter elongatarum. Stigma rimiformis solitaria adest, inter mediam partem valvae marginesque. Raphe filiformis, terminationibus proximalibus recta unilateraliter deflexis opposite stigma poris centralibus indistinctis. Fissurae distales curtae, leviter deflexae. Striae transapicales radiatae omnino, positae prope margines valvae, 16���18 in 10 ��m. Areolae 1���2 rimiformes. Ad margines, areola expansa adest. Type:��� ANTARCTICA. James Ross Island, Ulu Peninsula, Vondra II Lake, sample D39, leg. L. Nedbalova, coll. date 19/01/2009, slide no. BR-4244 (holotype BR, Fig. 78 is the encircled holotype specimen), slide PLP-192 (isotype University of Antwerp, Belgium), BRM-ZU8/10 (isotype BRM). Valves linear to linear-elliptic with broadly rounded, capitate apices (Figs 73���83). Stigma-bearing side almost straight with opposite side more convex. Valve margins clearly convex but asymmetrically constricted near valve middle. Valve length 18.5���23 ��m, valve width 6.5���8.1 ��m (n=15). Axial area broad, lanceolate, widening towards apices and central area, (Fig. 84). Central area forming rectangular to almost elliptical stauros, bordered by one series of small rounded to very weakly transapically elongated areolae (Figs 84, 85). One small slit-like solitary stigma present, halfway between valve centre and margin (Fig. 85). External raphe branches straight to weakly curved with unilaterally deflected proximal raphe endings, away from the stigma, terminating in almost unexpanded central pores (Fig. 85). Distal raphe fissures short, weakly deflected (Fig. 86). Transapical striae radiate throughout entire valve, positioned close to valve margin, 16���18 in 10 ��m (Fig. 84). Striae composed of 1���2 small, slitlike areolae and one enlarged areola close to valve margin (Fig. 84). Towards apices, striae composed only one areola. Internally, poroids of valve face occluded by hymens, forming continuous strip on each stria. Internal stigma opening consisting of small, rounded lipped slit. Stauros clearly developed (Fig. 87). Internal proximal raphe endings straight, terminating on stauros edge. Distal raphe endings terminating on small helictoglossae (Fig. 87). Habitat, Ecology and Distribution:��� Luticola tomsui has been found in only two samples from one lake on James Ross Island. The largest population was found in the epilithon of the shallow Vondra II Lake located on the Lagoons Mesa plateau near the ice-free area close to Croft Bay. The lake had a pH of 7.7, a low specific conductance value (53��S/cm) and was dominated by Nitzschia species including Nitzschia perminuta, N. paleacea and Nitzschia gracilis. Etymology:��� Luticola tomsui is named after my dear friend Jan Tom�� ů (Prague, Czech Republic). Observations: ��� The number of Luticola taxa with constricted valves is low thus confusion with L. tomsui is unlikely. Recently, L. adelae was described from White Lake on James Ross Island (Van de Vijver et al. 2011) and L. binodis (Hustedt 1922: 239) Edlund (in Edlund et al. 2001: 85) was reported from the nearby Livingston Island (South Shetland Islands) (Van de Vijver et al. 2011). Both are species with constricted valves. The valve size ranges of L. tomsui (L 18���23 ��m, W 6,5 ���8.0 ��m) is in between those of L. adelae and and L. binodis: L. adelae is smaller (L 16���20 ��m, W 5���6 ��m), L. binodis is larger (L �� 24 ��m, W �� 7,5 ��m). L. adelae and L. binodis both differ from L. tomsui in having a more slender valve outline and less inflated valve centre. Additionally, the number of areolae per stria in L. binodis is higher than L. tomsui and the axial area is smaller compared to the rather broad axial area in L. tomsui. Other species with constricted valves, such as L. mollis Lange-Bertalot & Rumrich (in Rumrich et al. 2000: 149) and L. incoacta (Hustedt 1966: 619) D.G.Mann (in Round et al. 1990: 670), have a higher number of areolae per stria, a narrower axial area and deeper constrictions. Finally, when L. tomsui is compared to L. nivalis, the latter has a valve outline with more undulations., Published as part of Kopalov��, Kate��ina, Nedbalov��, Linda, Haan, Myriam De & Vijver, Bart Van De, 2011, Description of five new species of the diatom genus Luticola (Bacillariophyta, Diadesmidaceae) found in lakes of James Ross Island (Maritime Antarctic Region), pp. 44-60 in Phytotaxa 27 on pages 56-58, DOI: 10.11646/phytotaxa.27.1.5, http://zenodo.org/record/4894204, {"references":["Van de Vijver, B., Zidarova, R. & de Haan, M. (2011) Four new Luticola taxa (Bacillariophyta) from the South Shetland Islands and James Ross Island (Maritime Antarctic Region). Nova Hedwigia 92: 137 - 158.","Hustedt, F. (1922) Die Bacillariaceen-Vegetation des Lunzer Seengebietes (Nieder-Osterreich). Internationale Revue der gesamten Hydrobiologie und Hydrographie 10: 40 - 74.","Edlund, M. B., Soninkhishsig, N., Williams, R. M. & Stoermer, E. F. (2001) Biodiversity of Mongolia: Checklist of diatoms, including new distributional reports of 31 taxa. Nova Hedwigia 72: 59 - 90.","Rumrich, U., Lange-Bertalot, H. and Rumrich, M. (2000) Diatoms of the Andes. From Venezuela to Patagonia / Tierra del Fuego and two additional contributions. Iconographia Diatomologica 9: 1 - 673.","Hustedt, F. (1966) Die Kieselalgen Deutschlands, Osterreichs und der Schweiz unter Berucksichtigung der ubrigen Lander Europas sowie der angrenzenden Meeresgebiete. In:. Rabenhorst, L. (Ed.), Kryptogamen Flora von Deutschland, Osterreich und der Schweiz. Akademische Verlagsgesellschaft m. b. h. Leipzig 7 (Teil 3, Lief. 4): 557 - 816.","Round, F. E., Crawford, R. M. & Mann, D. G. (1990) The diatoms: Biology and Morphology of the genera. Cambridge, Cambridge University Press, 747 pp."]}

Luticola evkae Kopalov��, sp. nov. (Figs 35���50) Valvae ellipticae-lanceolatae marginibus clare convexis apicibusque capitatis, late rotundatis. Valvae minores paene ellipticae. Longitudo 14���22 ��m, latitudo 5.4���8.2 ��m. Area axialis latissima, lanceolata, leviter dilata in aream centralem. Ad apices, area axialis clare dilata. Area centralis formans staurum paene rectangularem, leviter dilatatum ad margines, marginatumque serie una areolarum minutissimarum. Stigma rotundata, punctiformis solitaria adest inter mediam partem valvae marginesque. Raphe filiformis, recta terminationibus proximalibus unilateraliter deflexis opposita stigma poris centralibus leviter expansis. Fissurae distales curtae, leviter deflexis. Striae transapicales radiatae in parte centrali valvae ad fortiter radiatae ad apices, 16���20 in 10 ��m. Areolae rotundae 1���2 per striam terminans in areolam transapicaliter elongatam ad marginem. Type:��� ANTARCTICA. James Ross Island, Ulu Peninsula, Vondra II Lake, sample D39, leg. L. Nedbalov��, coll. date 19/01/2009, slide no. BR-4242 (holotype BR, Fig. 46 is the encircled holotype specimen), slide PLP-190 (isotype University of Antwerp, Belgium), BRM-ZU8/08 (isotype BRM). Valves elliptic-lanceolate with clearly convex margins and broadly rounded, capitate apices (Figs 35���46). Smaller valves almost elliptical (Fig. 47). Valve length 14���22 ��m, valve width 5,4���8,2 ��m (n=32). Axial area very broad, lanceolate, slightly widening towards central area (Fig. 48). Towards apices, axial area clearly widened (Fig. 49). Central area forming almost rectangular stauros, slightly widening towards margins, bordered by one series of very small rounded areolae (Fig. 50). One small, solitary, rounded stigma present, halfway between valve centre and margin (Figs 48, 50). Raphe branches filiform, straight with unilaterally deflected proximal endings away from stigma, terminating in weakly expanded central pores (Figs 48, 50). Distal fissures short, slightly deflected (Fig. 49). Transapical striae radiate near valve centre to strongly radiate towards poles, 16���20 in 10 ��m, composed of two (occasionally 1) small rounded areolae terminating in one clearly transapically elongated areola in middle part of valve near margin (Fig. 50). Areolae always rounded near apices (Fig. 49). Internal structure not observed. Habitat, Ecology and Distribution:��� Luticola evkae was described from the epilithon of a small, stable, shallow lake on Lagoons Mesa in the ice-free area close to Croft Bay. The lake had a pH of 7.7, a low specific conductance of 53 ��S/cm and was dominated by several Nitzschia species such as Nitzschia perminuta, Nitzschia paleacea Grunow (in Van Heurck 1881: pl. 68, Figs 9���10) and Nitzschia gracilis Hantzsch (1860:40). Etymology:���Named after my dear friend, Eva (Evka) Volemanov�� (Prague, Czech Republic). Observations: ��� Based on valve dimensions and the shape of the axial and central area of the valves, Luticola evkae may at first appear similar to Luticola dolia and L. doliiformis. These three species can, however, be clearly distinguished based on their contrasting valve outlines. Luticola evkae has a typical elliptical central part of the valve whereas both L. doliiformis and L. dolia always have more elongated valves with, in most cases, almost parallel margins (Esposito et al. 2008). The apices in L. evkae are always broader and more capitate than in L. dolia, which has more rostrate to weakly capitate apices. This can be appreciated by the differences in valve width/apex ratio, which is 1.70��0.18 (n=13) in L. evkae and 2.36��0.22 (n=13) in L. dolia; L. doliiformis has wider apices. Additionally, the shoulders just below the apices are more oblique in both L. dolia and L. doliiformis. In L. evkae, the outer row of areolae is always composed of transapically elongated areolae clearly visible in LM, whereas in L. doliiformis these areolae are always strictly rounded. Luticola austroatlantica is similar but distinguished by a different striation pattern with larger, usually elongated areolae. Moreover, L. austroatlantica lacks the broad axial area and has a more elongated valve outline. Smaller valves of L. austroatlantica with comparable valve dimensions as L. evkae always have rostrate apices contrary to the capitate apices in L. evkae. Other species that might be considered morphologically similar include L. muticopsis (and its smaller forms) and L. palearctica (Hustedt 1966: 613) D.G.Mann (in Round et al. 1990: 671). The former has a different valve outline, with one straight and one convex margin, clearly deflected proximal and distal raphe endings, rostrate apices and a narrower axial area (Van de Vijver & Mataloni 2008), whereas the latter is larger with more expanded apices and a higher areola density (Hustedt 1966). Finally, L. truncata has more areolae per stria (3���4 vs. 1���2 in L. evkae) with a more elliptical outline and truncated, non-capitate apices (Kopalov�� et al. 2009)., Published as part of Kopalov��, Kate��ina, Nedbalov��, Linda, Haan, Myriam De & Vijver, Bart Van De, 2011, Description of five new species of the diatom genus Luticola (Bacillariophyta, Diadesmidaceae) found in lakes of James Ross Island (Maritime Antarctic Region), pp. 44-60 in Phytotaxa 27 on pages 51-52, DOI: 10.11646/phytotaxa.27.1.5, http://zenodo.org/record/4894204, {"references":["Van Heurck, H. (1881) Synopsis des Diatomees de Belgique. Atlas. Ducaju & Cie., Anvers. pls 31 - 77.","Hantzsch, C. A. (1860) Neue Bacillarien: Nitzschia vivax var. elongata, Cymatopleura nobilis. Hedwigia 2 (7): 40.","Esposito, R. M. M., Spaulding, S. A., McKnight, D. M., Van de Vijver, B., Kopalova, K., Lubinski, D., Hall, B. & Whittaker, T. (2008) Inland diatoms from the McMurdo Dry Valleys and James Ross Island, Antarctica. Botany 86: 1378 - 1392.","Hustedt, F. (1966) Die Kieselalgen Deutschlands, Osterreichs und der Schweiz unter Berucksichtigung der ubrigen Lander Europas sowie der angrenzenden Meeresgebiete. In:. Rabenhorst, L. (Ed.), Kryptogamen Flora von Deutschland, Osterreich und der Schweiz. Akademische Verlagsgesellschaft m. b. h. Leipzig 7 (Teil 3, Lief. 4): 557 - 816.","Round, F. E., Crawford, R. M. & Mann, D. G. (1990) The diatoms: Biology and Morphology of the genera. Cambridge, Cambridge University Press, 747 pp.","Van de Vijver, B. & Mataloni, G. (2008) New and interesting species in the genus Luticola D. G. Mann (Bacillariophyta) from Deception Island (South Shetland Islands). Phycologia 47: 451 - 467.","Kopalova, K., Elster, J., Nedbalova, L. & Van de Vijver, B. (2009) Three new terrestrial diatom species from seepage area on James Ross Island (Antarctic Peninsula Region). Diatom Research 24: 113 - 122."]}

Luticola permuticopsis Kopalov�� & Van de Vijver, sp. nov. (Figs 51���72) Valvae lineares-lanceolatae ad lineares-ellipticae marginibus distincte convexis apicibusque late rotundatis, stricte capitatis. Longitudo 18.5���26.0 ��m, latitudo 7.3���9.2 ��m. Area axialis moderate angusta, linearis, paene non dilatata in aream centralem apicesque. Area centralis formans staurum rectangularem ad cuneatum, marginatum serie una areolarum rotundatarum magnarum. Stigma paene rotundata adest in extremo striae curate vel isolata inter mediam partem valvae marginesque. Raphe filiformis, recta, terminationibus proximalibus unilateraliter clare deflexis, poris centralibus leviter expansis. Fissurae distales deflectis, clare expansae. Striae transapicales fortiter radiatae omnino, 18���22 in 10 ��m. Areolae 3���6 per striam, moderate magnae. Type:��� ANTARCTICA. James Ross Island, Ulu Peninsula, Vondra IV Lake, sample D44, leg. L. Nedbalova, coll. date 19/01/2009, slide no. BR-4243 (holotype BR, Fig. 55 is the encircled holotype specimen), slide PLP-191 (isotype University of Antwerp, Belgium), BRM-ZU8/09 (isotype BRM). Valves linear-lanceolate to linear-elliptic with distinctly convex margins and broadly rounded, distinctly capitate apices (Figs 51���66). Valve length 18.5���26.0 �� m, valve width 7.3���9.2 �� m (n=15). Axial area moderately narrow, linear (Figs 67, 68), almost not widening towards apices (Fig. 72) and central area (Fig. 71). Central area forming a rectangular to wedge-shaped stauros, bordered by one series of large, rounded areolae. One solitary, almost rounded stigma present, usually at end of shortened stria, composed of 3 small, rounded areolae (Fig. 67) or isolated halfway between valve centre and margin (Fig. 71). External raphe branches straight with unilaterally clearly deflected, slightly expanded proximal raphe endings. Distal raphe fissures clearly elongated, deflected. Transapical striae rather strongly radiate throughout entire valve, composes of 3���6 moderately large, rounded areolae, 18���22 in 10 ��m. Near central area, areolae close to margin, clearly enlarged (Figs 67, 71) Internally, poroids of valve face occluded by hymens forming continuous strip on each stria (Fig. 69). Internal stigma opening consisting of almost rounded lipped slit (Fig. 70). Stauros clearly developed (Fig. 70). Internal proximal raphe endings straight, terminating on edge of stauros. Distal raphe endings terminating on small helictoglossae (Fig. 69). Habitat, Ecology and Distribution:��� Luticola permuticopsis has been found in a few lakes on James Ross Island on the Lagoons Mesa plateau near the ice-free area close to Croft Bay. The largest population was found in the epilithon of a perennial shallow lake with a pH of 7.4, a specific conductance value of 60 ��S/cm and a temperature 6.8 ��C. Dominant species in the sample include Nitzschia gracilis, N. paleacea and N. perminuta. Etymology: ��� permuticopsis refers to the close resemblance to L. muticopsis (per -: Latin for ���quite equally���). Observations: ��� The past few years, a large number of capitate species of Luticola have been separated from Luticola muticopsis s.l. Table 1 includes the main morphological characters of these species, in comparison to L. permuticopsis. Luticola permuticopsis can be separated from L. muticopsis by its typical valve outline: L. muticopsis has one straight and one convex margin, L. permuticopsis always has two convex margins; the apices in L. muticopsis are always more rostrate than capitate, contrary to L. permuticopsis, which has capitate, broadly rounded apices. Another important difference is formed by the areola pattern: in L. permuticopsis the striae are composed of 3���6 moderately large, densely packed areolae, whereas in L. muticopsis, there are only 3���4, more spaced areolae present, a feature easily discernible in LM (Van de Vijver & Mataloni 2008: p. 463, Fig. 77). Finally, the proximal raphe endings in L. permuticopsis are deflected, whereas in L. muticopsis, they are clearly bent. These differences separate the two species. *measurements based on line drawing in original publication Carlson (1913) described Navicula muticopsis f. capitata while Peragallo (1921) described Navicula muticopsis var. capitata ���both separated by their asymmetrical valve outline, with one straight and one convex margin. Both taxa have a strong affinity with L. muticopsis but type material of neither can be investigated due to lack of material. Other similar species are L. austroatlantica, L. palearctica, L. dolia and L. murrayi (West West 1911: 285) D.G.Mann (in Round et al. 1990: 671) sensu Hustedt (1966). Luticola austroatlantica can be separated by its more slender, elongated valve outline and a lower number of areolae per stria [2���3(4) vs. 3���6 in L. permuticopsis] (Esposito et al. 2008). Luticola permuticopsis has a more compact, robust outline. Moreover, near the apices, the areolae in L. permuticopsis continue almost entirely to the end, whereas in L. austroatlantica there is a hyaline zone surrounding the apices. Finally, the distal raphe fissures in L. austroatlantica are shorter than in L. permuticopsis. Luticola palearctica has similar valve dimensions to L. permuticopsis (Hustedt 1966) but a more clearly elliptical valve outline and broadly rounded, large capitate apices, showing little difference between the width of the apices and the width near the central area. In L. permuticopsis the apices are always clearly more narrower than the valve centre. Its discrimination from Luticola murrayi sensu Hustedt (1966) is based on valve outline, with L. murrayi sensu Hustedt (1966) having broadly rounded margins and apices. The latter is currently under revision and will be described as a new species separate from L. murrayi s.s. (Van de Vijver et al., unpubl.). Finally, L. dolia has straighter valve margins and a large axial area with only 1���3 areolae per stria (Esposito et al. 2008 and this paper). It can be separated from two other species present on James Ross Island: Luticola gigamuticopsis is much larger (length 38���46 ��m, width 14���17 ��m vs. 8.5���23.0 ��m and 6.5���8.1 ��m in L. permuticopsis) (Van de Vijver & Mataloni 2008); Luticola gaussii has an almost elliptical valve outline with constricted broadly rounded, large apices., Published as part of Kopalov��, Kate��ina, Nedbalov��, Linda, Haan, Myriam De & Vijver, Bart Van De, 2011, Description of five new species of the diatom genus Luticola (Bacillariophyta, Diadesmidaceae) found in lakes of James Ross Island (Maritime Antarctic Region), pp. 44-60 in Phytotaxa 27 on pages 53-56, DOI: 10.11646/phytotaxa.27.1.5, http://zenodo.org/record/4894204, {"references":["Van de Vijver, B. & Mataloni, G. (2008) New and interesting species in the genus Luticola D. G. Mann (Bacillariophyta) from Deception Island (South Shetland Islands). Phycologia 47: 451 - 467.","Carlson, G. W. F. (1913) Susswasseralgae aus der Antarktis, Sudgeorgien und den Falkland Inseln. Wissenschaftliche Ergebnisse der Schwedischen Sudpolar-Expedition 1901 - 1903, unter leitung von dr. Otto Nordenskjold: 4 (Botanique): 1 - 94.","Peragallo, M. (1921) Diatomees d'eau douce. Premiere partie. Deuxieme Expedition Antarctique Francaise (1908 - 1910) commande par le Dr. J. Charcot. Ouvrage publie sous les auspices du Ministere de l'Institution publique. Masson et cie, Paris, pp. 1 - 38.","West, W. & West, G. S. (1911) Freshwater algae. In: Murray, J. (ed.), Biology, vol. 1. Reports on the Scientific Investigations, British Antarctic Expedition 1907 - 09. Heinemann, London, pp. 263 - 298.","Round, F. E., Crawford, R. M. & Mann, D. G. (1990) The diatoms: Biology and Morphology of the genera. Cambridge, Cambridge University Press, 747 pp.","Hustedt, F. (1966) Die Kieselalgen Deutschlands, Osterreichs und der Schweiz unter Berucksichtigung der ubrigen Lander Europas sowie der angrenzenden Meeresgebiete. In:. Rabenhorst, L. (Ed.), Kryptogamen Flora von Deutschland, Osterreich und der Schweiz. Akademische Verlagsgesellschaft m. b. h. Leipzig 7 (Teil 3, Lief. 4): 557 - 816.","Esposito, R. M. M., Spaulding, S. A., McKnight, D. M., Van de Vijver, B., Kopalova, K., Lubinski, D., Hall, B. & Whittaker, T. (2008) Inland diatoms from the McMurdo Dry Valleys and James Ross Island, Antarctica. Botany 86: 1378 - 1392."]}