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Forty-two species of hydroids, excluding stylasterids, are reported in the present collection from the Northwestern Hawaiian Islands. Of these, four are anthoathecates and 38 are leptothecates. Among the latter, Sertularella affinicostata and Monotheca gibbosa are described as new species. The binomen Halopteris longibrachia is proposed as a new replacement name for Plumularia polymorpha var. sibogae Billard, 1913, an invalid junior primary homonym of P. sibogae Billard, 1911. Based largely on evidence from earlier molecular phylogenies, the genus Disertasia Neppi, 1917 is resurrected to accommodate species including Dynamena crisioides Lamouroux, 1824, Sertularia disticha Bosc, 1802, and Sia. moluccana Pictet, 1893. Sertularella robusta Coughtrey, 1876 is an invalid junior primary homonym of Sla. gayi var. robusta Allman, 1874a, and has been replaced here by the binomen Sla. quasiplana Trebilcock, 1928, originally described as Sla. robusta var. quasiplana Trebilcock, 1928. Clytia hummelincki (Leloup, 1935) is referred to the synonymy of its senior subjective synonym, C. brevithecata (Thornely, 1900). Following Reversal of Precedence provisions in the International Code of Zoological Nomenclature to preserve prevailing usage of binomena, the familiar names Sia. disticha Bosc, 1802 (also known as Dynamena disticha) and Lytocarpia phyteuma (Stechow, 1919b) are designated nomena protecta and assigned precedence over their virtually unknown senior synonyms Hydra quinternana Bosc, 1797 and Aglaophenia clavicula Whitelegge, 1899, respectively, names now reduced to the status of nomena oblita. Twenty species are reported for the first time from Hawaii [Eudendrium merulum Watson, 1985, Phialellidae (undetermined), Hebella sp., Hebellopsis scandens (Bale, 1888), H. sibogae Billard, 1942, Clytia brevithecata, C. linearis (Thornely, 1900), C. cf. noliformis (McCrady, 1859), Halecium sp., Sla. affinicostata, Sla. angulosa Bale, 1894, Pasya heterodonta (Jarvis, 1922), Tridentata orthogonalis (Gibbons Ryland, 1989), Pycnotheca producta (Bale, 1881), Monotheca gibbosa, H. longibrachia, A. postdentata Billard, 1913, A. suensonii Jderholm, 1896, A. whiteleggei Bale, 1888, and L. flexuosa (Lamouroux, 1816)]. Sertularia orthogonalis, reported for only the third time worldwide, is assigned to the genus Tridentata Stechow, 1920. Hydroids of the NOWRAMP 2002 collection consisted largely of presumptive widespread species, with over 75% of them having been reported elsewhere in the tropical Indo-west Pacific region.

Tima nigroannulata sp. nov. is described from medusae collected in shallow waters of four prefectures on the Pacific coast of Japan (Miyagi, Fukushima, Kanagawa, and Miyazaki), as well as from cultures maintained at two aquaria (Enoshima Aquarium, Kanagawa Prefecture; Tsuruoka City Kamo Aquarium, Yamagata Prefecture). Adult medusae differ from those of other known species of the genus Tima Eschscholtz, 1829 in the following combination of characters: (1) umbrella usually hemispherical or higher, (2) marginal tentacles up to 50 or more in number; and (3) black pigment granules form a ring around the umbrella rim, and sometimes extend onto the tentacles and radial canals. Their hydroids, from aquarium cultures, have stolonal colonies with pedicels of varied length, vestigial hydrothecae, slender and vase- to club-shaped hydranths, and a whorl of about 20 filiform tentacles with an intertentacular web basally. Medusa buds develop singly within gonothecae that arise from the hydrothecal pedicels. The cnidomes of both hydroid and medusa stages comprise heteronemes, provisionally identified as microbasic mastigophores. Medusae of T. nigroannulata are confirmed as a unique, cohesive lineage by comparing mtDNA COI sequence fragments with those from two congeners, resulting in three well-supported reciprocally monophyletic clades, one representing each species. Records of the western Atlantic medusa Tima formosa L. Agassiz, 1862 from Japan overlap those of T. nigroannulata , and are believed to have been based on the new species described herein.

Fourteen species of hydroids, collected during August 2019 by ROV SuBastian of the Schmidt Ocean Institute, are reported from the Emperor Seamount chain in the western North Pacific Ocean. Two others, Candelabrum sp. and Eudendrium sp., were observed only on videos taken by the ROV. From collections and video observations, eight species of hydroids were found at Jingū Seamount, three at Yomei, Nintoku, and Annei seamounts, and one at Koko Seamount and Hess Rise. At Suiko and Godaigo seamounts, hydroids were seen in videos but they could not be identified. Latebrahydra schulzei, an endobiotic associate of the hexactinellid sponge Walteria flemmingii Schulze, 1886 from Annei Seamount and Hess Rise, is described as a new genus and species tentatively attributed to Hydractiniidae L. Agassiz, 1862. Another new species, Hydractinia galeai, is described from Jingū Seamount. Among its distinctive characters is a zooid termed a sellectozooid, likely serving in both food capture and defence. Hydroids examined from Yomei, Nintoku, and Jingū seamounts are elements of a cold-water fauna occurring in the North Pacific Boreal Bathyal province, while those of Annei and Koko seamounts, and Hess Rise, are part of the biota of the Central North Pacific Bathyal province. Hydroids identified as Bouillonia sp., from Nintoku Seamount, represent the first record of this predominantly deep water tubulariid genus in the North Pacific Ocean. Bonneviella superba Nutting, 1915, from Jingū Seamount, is reported for the first time outside the Aleutian Islands. Bonneviella cf. gracilis Fraser, 1939, known elsewhere only from Dease Strait in the western Canadian Arctic, was also collected on Jingū. In addition to hydroids, medusae of Ptychogastria polaris Allman, 1878 were observed on videos from Nintoku, Jingū, Annei, and Koko seamounts at depths between 2423-1422 m. An unidentified siphonophore was observed near bottom at 2282 m on Nintoku Seamount.

Massive accumulations of pelagic species of Sargassum have generated recent social, economic and ecological problems along Caribbean shores. In the Mexican Caribbean, these events have prompted the study of diverse biological and ecological aspects of these macroalgae. However, studies on their associated biota, including Hydrozoa, remain scarce. This research provides important species observations in an area where data is lacking. The occurrence and percent cover of hydroids on Sargassum thalli collected on the beach at Puerto Morelos, Quintana Roo, Mexico from April 2018 to March 2019 was studied. Three pelagic species and morphotypes of Sargassum from this area were analyzed: Sargassum fluitans III, S. natans I and S. natans VIII, as well as a benthic species, S. polyceratium var. ovatum . A total of 14 taxa of hydroids, belonging to the superorders "Anthoathecata" and Leptothecata, were identified. In our study, more hydroid taxa were observed on axes of the different species of Sargassum than on leaves or aerocysts. In general, the greatest species richness of hydroids was observed from February to April. Results show that live hydrozoans attached to pelagic Sargassum are transported into the area. This should be considered in future management measures that address the recurring coastal abundance of Sargassum and its associated biota in the Caribbean region., Competing Interests: The authors declare that they have no competing interests., (© 2020 Mendoza-Becerril et al.)

This report is based on a small collection of hydroids from the Hawaiian Islands, in the central Pacific Ocean. Most of the examined material was obtained by staff of the Bernice Pauahi Bishop Museum, Honolulu, during surveys for nonindigenous marine species in shallow, sheltered, inshore or nearshore waters, and especially in harbours, bays, and lagoons. In all, 34 species of leptothecate hydroids, assigned to 14 families and 20 genera, were identified and are discussed. One of them, based on a single infertile colony with a damaged hydrotheca, was identified provisionally only to the rank of suborder. Given the limited geographic and bathymetric focus of the surveys, only four of the species, Clytia thornelyi, Halecium sibogae, Macrorhynchia balei, and M. hawaiensis, were collected at depths greater than 25 m. Seven species, Cirrholovenia tetranema Kramp, 1959, Orthopyxis crenata (Hartlaub, 1901), Clytia elongata Marktanner-Turneretscher, 1890, C. paulensis (Vanhöffen, 1910), Tridentata maldivensis (Borradaile, 1905), Monotheca flexuosa (Bale, 1894), and a hydroid identified only as Eirenida (undetermined), are recorded from Hawaii for the first time. Three others, Lytocarpia nigra (Nutting, 1905) Macrorhynchia balei (Nutting, 1905), and M. hawaiensis (Nutting, 1905), have their type localities in Hawaii, with the last of these being known to date only from the Hawaiian archipelago. Most of the species are well-known from shallow water areas across the tropical and subtropical Indo-Pacific region, and over half of them have been reported as well from warm waters in the Atlantic Ocean. Their existence in the remote islands of Hawaii is attributed to long-range dispersal by both natural and human-mediated means, including shipping.

Sixty species of hydroids, assigned to 24 families and 39 genera, are recognized and discussed in a collection of material from the southwest coast of Florida. One new species (Clytia joycei) is described from turtlegrass (Thalassia testudinum) and reported as well from the Caribbean coast of Panama. Under provisions of the First Reviser Principle in the International Code of Zoological Nomenclature, Antennopsis nigra Nutting, 1900 is assigned precedence over its simultaneous synonym A. longicorna Nutting, 1900. Also included as a synonym of A. nigra is A. sinuosa Fraser, 1947b. The species is now assigned to Nemertesia Lamouroux, 1816, as N. nigra. Following Reversal of Precedence provisions in the code, the well-known name Halecium nanum Alder, 1859 is designated as valid and conserved as a nomen protectum, while Hydra articulata Bosc, 1797 is relegated to a nomen oblitum. The genus Monotheca Nutting, 1900 is upheld as valid on the basis of both morphological and molecular evidence. Sertularia pourtalesi Nutting, 1904, a seldom-reported species, is assigned to Dynamena Lamouroux, 1812 and recognized as distinct from D. disticha (Bosc, 1802). Calyptospadix cerulea Clarke, 1882 and Bimeria franciscana Torrey, 1902 (also known as Garveia franciscana) are taken to be conspecific, with Calyptospadix Clarke, 1882 treated as a valid genus. Confusion over the identity of Lovenella gracilis Clarke, 1882 in literature on North American hydroids is addressed, and topotypic specimens from the Chesapeake Bay region are illustrated to document characters that distinguish the species. Campanularia colombiana (Wedler, 1976) is reported for the first time outside the Caribbean coast of Colombia. The fauna studied here consists largely of species known to occur in the tropical and subtropical western Atlantic. [Zoobank URL: urn:lsid:zoobank.org:act:4C926BE2-D75D-449A-9EAD-14CADACFFADD].

An account is given of the names of families, genera, and species of hydroids established by C.M. Fraser of Canada, excluding those from Allan Hancock Pacific Expeditions and the Allan Hancock Caribbean Sea Expedition. The names of four families, 11 genera, and 101 species are attributed to him in this work, complementing those of another two genera and 164 species described by Fraser in various Allan Hancock publications. Information is provided on type localities of his new species, on locations and kinds of type material in existence, where known, and on the current taxonomic status of families, genera, and species described by him in works reviewed herein. Two replacement names (Thuiaria geniculata Fraser, 1918a and Salacia fraseri Calder, 1991) exist for Thuiaria distans Fraser, 1914a (not Thuiaria distans Allman, 1877). The widely overlooked senior synonym, T. geniculata, is recognized as the valid name of the species. Diphasia alta nom. nov. is proposed as a new replacement name for the permanently invalid junior primary homonym Diphasia robusta Fraser, 1943a (not D. attenuata robusta Billard, 1924). In addition, Cryptolaria crassa nom. nov. is proposed as a new replacement name for the junior secondary homonym Cryptolaria rigida (Fraser, 1948) [not C. rigida (Fraser, 1940a)]. Lectotypes have been designated for 47 of the species to establish objective standards for application of their names. Corymorpha adventitia Fraser, 1941b, from the Pacific coast of Panama, is assigned to Ralpharia Watson, 1980, as R. adventitia. No type specimens are known to exist for seven of the species considered, including one holotype (of Hebella eximia Fraser, 1944a) missing from its bottle. Particular attention has been paid to dating and chronology of the 51 publications of Fraser covered in this work. Earlier bibliographic errors are corrected, most notably establishing that the book Distribution and relationship in American hydroids was published in early 1947 rather than 1946 as per the title page.

Two new species of hydroids, Eudendrium bleakneyi and Halecium praeparvum, are described from the Bay of Fundy. Fourteen others, Tubularia acadiae Petersen, 1990, Coryne pusilla Gaertner, 1774, Sarsia lovenii (M. Sars, 1846), Zanclea implexa (Alder, 1856), Corydendrium dispar Kramp, 1935, Rhizogeton fusiformis L. Agassiz, 1862, Bougainvillia muscus (Allman, 1863), Rhizorhagium roseum M. Sars, in G.O. Sars, 1874, Hydractinia symbiolongicarpus Buss & Yund, 1989, Eudendrium vaginatum Allman, 1863, Tiaropsis multicirrata (M. Sars, 1835), Obelia bidentata S.F. Clark, 1875, Halecium marsupiale Bergh, 1887, and Sertularella gigantea Hincks, 1874, are reported, with collection data, for the first time from the bay. All but Coryne pusilla, Rhizorhagium roseum, Eudendrium vaginatum, and Sertularella gigantea are also new to Atlantic Canada, while Zanclea implexa, Corydendrium dispar, and Halecium marsupiale are reported for the first time in the western North Atlantic. Two of those species, Hydractinia symbiolongicarpus and Obelia bidentata, are disjunct in distribution, with core populations occurring in warmer waters to the south of Cape Cod, Massachusetts. Both were discovered in Minas Basin, a hydrographically distinct embayment where surface water temperatures are much warmer during summer than in the perpetually cold lower Bay of Fundy. Rhizorhagium roseum and the subfamily Rhizorhagiinae are transferred from family Bougainvilliidae Lütken, 1850 to Pandeidae Haeckel, 1879. An annotated checklist of hydroids from the Fundy region, based on previously published reports and on new records of species, is added as an appendix. Included in the checklist are 43 species of anthoathecates and 75 species of leptothecates, referable to 30 families and 56 genera. Families with the most species were Sertulariidae (23), Haleciidae (13), Eudendriidae (11), and Obeliidae (10). Biogeographically, the aggregate hydroid fauna of the bay conforms with that occurring in other parts of the Western Atlantic Boreal Region. Halecium permodicum is proposed as a replacement name for Halecium minor Fraser, 1935, an invalid junior homonym of H. minor Pictet, 1893.

One new genus (Schizoplumularia) and three new species (Schizoplumularia vervoorti, S. geniculata and S. elegans) of plumulariids are recognized and described from large collections of plumularioid hydroids collected in New Caledonia and vicinity during several French expeditions. During taxonomic studies of these hydroids, colonies were compared with type material of Plumularia insignis Allman, 1883 and several other similar species-group taxa. As a result, three of the latter (P. flabellum Allman, 1883, P. conjuncta Billard, 1913, and P. billardi nom. nov.) are recognized as valid in addition to P. insignis. The binomen P. billardi is a replacement name for P. insignis var. gracilis Billard, 1913. In being elevated to the rank of species in this work, it becomes an invalid junior primary homonym of several others having the same name.

The binomen Nemopsis gibbesii McCrady, 1859, originally applied to a species of hydromedusa and its supposed hydroid from South Carolina, USA, has been known for more than a century to encompass two species. The medusa stage is conspecific with that of Nemopsis bachei L. Agassiz, 1849, while the hydroid stage is referable to the genus Margelopsis Hartlaub, 1897. Both that hydroid, and the medusa stage now subjectively linked to it, are commonly assigned to M. gibbesii. With no type having ever been designated for McCrady's species, a lectotype is designated to stabilize nomenclature of the species and serve as the standard for application of the name. In the absence of type specimens, an illustration of the hydroid of N. gibbesii by McCrady is chosen as lectotype, thereby conserving the name Margelopsis gibbesii in its accustomed usage. Hydroids and medusae of the species are re-described from new material, the cnidome of both stages is characterized, and a taxonomic review is given. The hydroid stage is reported for the first time since its original description in the mid-19th century. Medusae of M. gibbesii are also seen infrequently, having been reported only six times earlier.

George James Allman (1812-1898), acclaimed for pioneering studies of Hydrozoa and Bryozoa, was born in Cork, Ireland. He earned B.A. (1839) and M.B. (1843) degrees at Trinity College, Dublin, and an M.D. (1847) from Trinity College and Oxford University. Choosing academia over medicine, he served as Professor of Botany, University of Dublin (1844-1855), and as Regius Professor of Natural History, University of Edinburgh (1855-1870). Allman initially undertook research on freshwater bryozoans, but his interests later turned to marine hydroids. His bibliography, with publication dates retraced herein, comprises more than 200 titles. Most important of these were monographs on limnic Bryozoa (1857) and "gymnoblastic" or anthoathecate Hydrozoa (1871, 1872). Other prime works were on hydroids from the Straits of Florida (1877) and from the Challenger Expedition (1883, 1888). He named 22 families, 64 genera and 283 species of Hydrozoa, along with three families and nine species of Bryozoa. Of these, names of some five families, 19 genera, and 146 species of hydrozoans, along with three families and three species of bryozoans, are currently recognized as valid. For distinguished academic service, Allman was awarded the Royal Medal (Royal Society of London, 1873), the Brisbane Prize (Royal Society of Edinburgh, 1873), the Cunningham Medal (Royal Irish Academy, 1878), the Gold Medal (Linnean Society of London, 1896), and an LL.D. from the University of Edinburgh (1873). He died 24 November 1898 in Parkstone, Dorset, England. Two genera and 22 species have been named in his honour.

Five species of aglaopheniid hydroids (Aglaophenopsis cornuta, Cladocarpus diana, C. formosus, C. integer, and Nematocarpus ramuliferus) were collected from the Flemish Cap, Flemish Pass, and Grand Banks of Newfoundland during surveys with bottom trawls, rock dredges, and scallop gear. All are infrequently reported species, with C. diana being discovered for the first time since its original description from Iceland. We document here the southernmost collections of C. diana and N. ramuliferus, both previously unknown in the western Atlantic. Each of the five species is described and illustrated based on fertile material, a key is provided for their identification, and bathymetric distributions are noted. Known depth ranges are extended for A. cornuta, C. diana, and C. integer. Aglaophenopsis and Nematocarpus are recognized as genera distinct from the polyphyletic Cladocarpus, based on the unique structure of the phylactocarp in the former, and the existence of appendages with nematothecae (ramuli) on almost all thecate internodes of hydrocladia in the latter. These appendages occur even in the absence of gonothecae, and are here considered defensive structures that protect the hydranths. In differing from typical phylactocarps, we accept the contention that they are characters of generic value.

Harry Beal Torrey was born on 22 May 1873 in Boston, Massachusetts. Two years later his family moved to Oakland, California. Torrey earned B.S. and M.S. degrees in zoology from the University of California, Berkeley, in 1895 and 1898 respectively, a Ph.D. in zoology from Columbia University in 1903, and an M.D. from the Medical College of Cornell University in 1927. He began his academic career as a marine biologist, investigating taxonomy, reproduction, morphology, development, regeneration, and behaviour of cnidarians of the west coast of the United States, but his research interests soon shifted to experimental biology and endocrinology. He eventually entered the field of medicine, specializing in public health, and served as a physician and hospital administrator. Torrey held academic positions at the University of California, Berkeley (1895-1912), the Marine Biological Association of San Diego (1903-1912), Reed College (1912-1920), the University of Oregon (1920-1926), and Stanford University (1928-1938). Following retirement from academia, he served as Director of the Children's Hospital of the East Bay, Oakland, California, from 1938 to 1942. In retirement, he continued an association with the University of California at Berkeley, near his home. Of 84 publications by him listed herein, 31 dealt with coelenterates. This paper focuses on his early research on coelenterate biology, and especially his contributions to taxonomy of hydroids. He was author or coauthor of six genera and 48 species-group taxa of Cnidaria, and he also described one new species each of Ctenophora and Phoronida. Although he abandoned systematic work early in his career, his most widely cited publication is a taxonomic monograph on hydroids of the west coast of North America, published in 1902. He died, at age 97, on 9 September 1970.

Zyzzyzus rubusidaeus, sp. nov., is described from inshore waters near the northern tip of Vancouver Island, British Columbia, Canada. Specimens were collected on rocky bottoms amongst barnacles, sponges, and compound ascidians at a depth of 18 m in Weynton Passage, Broughton Strait, during March, July, and October 2012. Polyps tend to grow in dense aggregations, often covering several square centimetres. Hydroids of Z. rubusidaeus most closely resemble those of Z. robustus Petersen, 1990 from Greenland, but differ in having aboral tentacles that are scattered in a narrow band around the base of the hydranth rather than occurring in a single whorl, thin and transparent instead of thick and stiff perisarc around hydrocaulus and tubers, and gonophores that arise from simple pedicels instead of short, stout branches. Possible embryos were present in female gonophores, although structures recognizable as actinula larvae have not been observed. The cnidome comprises small and large stenoteles, desmonemes, microbasic euryteles, basitrichs, and isorhizas. Polyps are a raspberry colour in life, a hue that has faded but little in our formalin-preserved material. Discovery of this hydroid brings the number of species currently recognized in genus Zyzzyzus Stechow, 1921 to seven.

This paper gives a systematic account of 67 species, referable to 22 families and 40 genera, identified in a small collection of hydroids from the central Atlantic coast of Florida between Melbourne and Palm Beach. The fauna mostly comprises an assemblage of tropical western Atlantic species ranging northwards along the southeastern coast of the United States. One new species, Lafoea intorta, is described. Applying Reversal of Precedence provisions in zoological nomenclature, the widely-used generic name Halopteris Allman, 1877 is designated as valid and as a nomen protectum, while its virtually unused senior synonym Halicornaria Hincks, 1865 (not Halicornaria Allman, 1874) is reduced to a nomen oblitum. The genus Pasya Stechow, 1922 is resurrected for the hydroid generally known as Dynamena quadridentata (Ellis & Solander, 1786). Laomedea tottoni Leloup, 1935 is shown to be a junior objective synonym of Clytia fragilis Congdon, 1907, which in turn is a junior subjective synonym of Clytia linearis (Thornely, 1900). Obelia oxydentata Stechow, 1914 is recognized as distinct from O. bidentata Clark, 1875. Hincksella brevitheca Galea, 2009, first described from Cuba, is reported for only the second time; records of the species are added here from Grand Cayman Island and the Caribbean coast of Panama as well as from the Atlantic coast of Florida. Also reported for the second time is Antennella incerta Galea, 2010, previ-ously known only from Guadeloupe in the Caribbean Sea. The true Halopteris diaphana (Heller, 1868), known from the Mediterranean Sea and from Brazil, is reported for the first time from the western North Atlantic. Earlier records of the species in the region are based on misidentifications of H. alternata (Nutting, 1900). Male gonothecae of Halecium calderi Galea, 2010 are reported and illustrated for the first time.

Charles Wesley Hargitt was born near Lawrenceburg, Indiana, USA, and died at Syracuse, New York. After a brief career as a Methodist Episcopal Minister, he carried out graduate studies in biology at Illinois Wesleyan University and Ohio University. He served briefly on the faculty at Moores Hill College and later at Miami University of Ohio before receiving an appointment at Syracuse University. Hargitt spent 36 years at Syracuse, and for 21 years was a trustee of the Marine Biological Laboratory, Woods Hole, Massachusetts. His research encompassed animal behaviour, cell biology, development, ecology, natural history, and taxonomy, as well as education, eugenics, and theology, and he wrote or contributed to more than 100 publications in science. Approximately half of these were on Cnidaria, with 41 of them on Hydrozoa. His most important works in hydrozoan taxonomy were on species of the Woods Hole region, the Philippines, and south China. Hargitt was author of three genera and 48 species and subspecies ascribed to Hydrozoa, seven species of Anthozoa, and one species of Cubozoa. Four species of hydroids are named in his honour.

Thomas Hincks was born 15 July 1818 in Exeter, England. He attended Manchester New College, York, from 1833 to 1839, and received a B.A. from the University of London in 1840. In 1839 he commenced a 30-year career as a cleric, and served with distinction at Unitarian chapels in Ireland and England. Meanwhile, he enthusiastically pursued interests in natural history. A breakdown in his health and permanent voice impairment during 1867-68 while at Mill Hill Chapel, Leeds, forced him reluctantly to resign from active ministry in 1869. He moved to Taunton and later to Clifton, and devoted much of the rest of his life to natural history. Hincks was elected a Fellow of the Royal Society of London in 1872 for noteworthy contributions to natural history. Foremost among his publications in science were "A history of the British hydroid zoophytes" (1868) and "A history of the British marine Polyzoa" (1880). Hincks named 24 families, 52 genera and 360 species and subspecies of invertebrates, mostly Bryozoa and Hydrozoa. Hincks died 25 January 1899 in Clifton, and was buried in Leeds. His important bryozoan and hydroid collections are in the Natural History Museum, London. At least six genera and 13 species of invertebrates are named in his honour.

Yolk proteins of prematuration occytes and postmaturation eggs were compared by SDS gel electrophoresis in several teleosts, including freshwater species that produce demersal eggs, estuarine and marine species with demersal eggs, and marine species with pelagic eggs. In certain teleosts distinct changes in yolk protein banding patterns during oocyte maturation are suggestive of extensive secondary proteolysis of yolk proteins at this time; proteolysis is most pronounced in marine fishes with pelagic eggs. In many teleosts the oocyte swells by hydration during maturation; this hydration is also most pronounced in marine fishes with pelagic eggs. The extent of yolk proteolysis is well correlated with the extent of oocyte hydration during maturation.

The effects of several steroids on the maturation of follicle-enclosed oocytes of the mummichog Fundulus heteroclitus in vitro were examined. At a relatively high concentration (1.0 microgram/ml), a number of different steroids, including pregnenolone, 17 alpha-hydroxypregnenolone, corticosterone, cortisol, 11-deoxycorticosterone, 11-deoxycortisol, androstenedione, testosterone, progesterone, 17 alpha-hydroxyprogesterone, 20 beta-dihydroprogesterone, and 17 alpha-hydroxy-20 beta-dihydroprogesterone, were able to induce germinal vesicle breakdown (GVBD) in prematuration oocytes. Cholesterol, 17 beta-estradiol, 11-ketotestosterone, and 11 beta-hydroxytestosterone were totally ineffective. In general, 11-oxysteroids tended to be less effective than their 11-deoxysteroid counterparts. Two 20 beta-dihydroprogestins--17 alpha-hydroxy-20 beta-dihydroprogesterone and 20 beta-dihydroprogesterone--were the most potent maturation-inducing steroids, initiating 50% GVBD at 1 ng/ml in follicles obtained from ovaries containing mature or maturing follicles in vivo, or at 2.5-4.0 ng/ml in follicles from ovaries lacking mature or maturing oocytes in vivo. These results are consistent with several previous studies involving salmonids and various other teleosts, and suggest a possible physiological role for a 20 beta-dihydroprogestin in the resumption of meiotic maturation in F. heteroclitus.