MEDUSAE OF THE WORLD VOLUME I THE HYDROMEDUSAE BY ALFRED GOLDSBOROUGH MAYER WASHINGTON, D. C. PUBLISHED BY THE CARNEGIE INSTITUTION OF WASHINGTON 1910 CARNEGIE INSTITUTION OF WASHINGTON PUBLICATION No. 109, VOL. I Copies of this Book were first issuec* AUG9 1910 CONTENTS. VOLUME I. Introduction i~4 Synopsis of Genera of the Hydromedusas 5-16 Medusae Milleporinae 16 Anthomedusae 17-196 Genera of the Anthomedusae: Pachycordyle 21 Zancleopsis 91 Podocoryne 135 Amaithasa 22 Pteronema 92 Turritopsis 143 Pennaria 23 Eleutheria 93 Oceania 146 Trichorhiza 28 Mnestra 96 Stylactis 149 Steenstrupia 29 Ctenaria 98 Thamnostylus 151 Hybocodon 37 Cladonema 98 Thamnitis 152 Microcampana 44 Dendronema 102 Lymnorea 153 Dicodonium 44 Protiara 105 Bougainvillia 155 Sarsia 47 Heterotiara 107 Nemopsis 172 Stnuridiosarsia 64 Stomotoca 108 Rathkea • • '75 llydrichthys 66 Dissonema 115 Chiarella 182 Eucodonium 68 Pandea 116 Bythotiara ..185 Ectopltura 68 Turns I2O Sibogita 186, vol. 2 4QI Corynitis 71 Conis 130 Niobia 187 Slabberia 73 Calycopsis 130, vol. 2 491 Proboscidactyla. . . . . . 188 Margelopsis 80 Cytsis ... ,:. .-...- ... 132 Willsia . . 193 Zanclea 85 Leptomedusae '..'.' • .196-230 Genera of the Leptomedusae: Thaumantias 198. Staurodiscus 213 Dichotomia m Laodicea 201 1'tvchogena 214 Dipleurosoma 224 Melicertum 207 I'olyorchis 218 Toxorchis 228 Melicertissa 209 Spirocodon 219 Netocertoides. . . .229 Orchistoma 21 r Cannota 221 Monobrachium. . --230 Timoides . . ..212 Cuvieria 221 MEDUSAE OF THE WORLD. THE HYDROMEDUSAE. INTRODUCTION. This work was commenced in 1892 at the suggestion of Dr. Alexander Agassiz while I was a student in his marine laboratory at Newport. Dr. Agassiz's plan was that we produce conjointly a work upon the Medusae, Siphonophora, and Ctenophorae of the Atlantic coast of North America. In pursuance of this plan, Dr. Agassiz sent me upon expeditions to Halifax, Nova Scotia; Eastport, Maine; Charleston, South Carolina; and Tortugas, Florida. It was also my privilege to accompany him as his assistant upon his expeditions to the Bahamas, and to the coral regions of the tropical Pacific. During these years the majority of our American species were captured and drawings of them made from life. The description of all of the then known American Atlantic forms was com- pleted by me in 1900, but unfortunately the pressure of other and more important work prevented the revision of the manuscript by Dr. Agassiz, and thus it remained in the Museum of Comparative Zoology at Harvard University until 1904, when Dr. Agassiz generously returned it to me with permission to publish it in any manner whatsoever. Thus the original plan was reluctantly abandoned. During the four years that elapsed while the manuscript lay unstudied at Harvard, new forms had been discovered along our coast; and Nutting and Hargitt had published their papers upon the hydroids and medusae of the Woods Hole region. It was necessary to thoroughly revise the manuscript, and in order to render it of greater service, I have attempted to extend the original work to include descrip- tions of all known forms of medusae from all parts of the world. This extension was made possible through the generous establishment by the Carnegie Institution of Washington of a Marine Research Laboratory at Tortugas, Florida. Many forms were collected upon a cruise of the Carnegie Institution yacht Physalia from Boothbay Harbor, Maine, to Tortugas, Florida; and new or interesting medusae have been obtained each season upon excursions over the tropical Gulf Stream, and among the Bahamas. My official position in connection with the laboratory has afforded me every possible facility in time and opportunity tor tilt- prosecution of these studies, and I can not too kindly express my sense of gratitude to the executive officers of the Carnegie Institution tor their generous support. To Geheimrath Prof. Dr. Anton Dohrn, and to his able corps of associates at the Stazione Zoologica, I am indebted for numerous kindnesses shown to me during my visit to the laboratory at Naples from November to February, 1907 and 1908. I have also enjoyed full privileges of study in the libraries of the Museum of Comparative Zoology at Harvard University; in the Boston Society of Natural 1 2 MEDUSvE OF THE WORLD. History; the American Museum of Natural History; Columbia University, the National Museum at Washington, and the Museum of the Brooklyn Institute of Arts and Sciences. Through these facilities I have been enabled to review nearly all of the published works upon medusae, but the review of literature can not pre- tend to completeness for 1907 and 1908, although all papers of those years which the author could discover are recorded. Moreover, Profs. William K. Brooks and Louis Murbach have been so kind as to lend some of their original drawings, which are reproduced in this work, and the following gentlemen have generously granted permission for the reproduction of figures from their published works, thus enabling us to present text-figures of many forms which would otherwise have been represented merely by descriptions: Dr. Alexander Agassiz, Director of the Museum of Comparative Zoology at Harvard University; Dr. Henry B. Bigelow, of Harvard; Dr. R. P. Bigelow, of the Massa- chusetts Institute of Technology; Prof. Edward T. Browne, of the University of London; Prof. Dr. Carl Chun, of Leipzig; Prof. Dr. S. Goto of Tokyo; Geheimrath Prof. Dr. Ernst Haeckel, of Jena; Prof. C. W. Hargitt, of Syracuse University; Prof. Dr. Cl. Hartlaub, of Helgoland; Prof. W. C. M'Intosh, of Aber- deen University; Prof. Dr. Otto Maas, of Miinchen; Prof. C. C. Nutting, of Iowa; Prof. Henry F. Perkins, of Vermont; and Prof. Dr. Ernst Vanhoffen, of Kiel. I have always felt that each working naturalist owes it as a duty to science to produce some general systematic work, and this has been an actuating motive in the production of this book. But chiefly have I been moved to the task through respect for the wishes of my generous friend and master in science, Alexander Agassiz. Nor can one remain insensible to the rare grace of form and delicate beauty of color of these creatures of the sea, associated as their study is with mem- orials of the labors of a host of distinguished naturalists. Dry though these pages must be to the reader, to the writer they are replete with memories of the ocean in many moods, of the palm-edged lagoons of coral islands sparkling in the tropic sun, of the cold, gray waters of the northern sea bestrewn with floating ice, of days of withering calm in the heat of the torrid zone, and of adventure in the hurricane ; all centering around the absorbing study of the medusa?. Love, not logic, impels the naturalist to his work. This book attempts to present a new classification of the medusae. With every respect for Haeckel's great work, it has appeared to me that its subdivisions are often too precise to be convenient, and too artificial to accord with nature. More- over, many of Haeckel's genera are founded upon intergrading characters, and are thus imperfectly separated. The young of many medusae appear in one genus, and the adults in another. The aim of Haeckel's system is to emphasize distinctions, whereas my aim is to indicate relationships. I therefore attempt to separate genera upon positive, not upon relative, distinctions. For example, if we define one genus as having a narrow manubrium (Margelis), and another as having a wide manu- brium (Boiigamvillta), we must either institute a third genus for newly-discovered medusae with manubria of moderate width or place them doubtfully in one or the other of the genera of the extreme members of the series. On the other hand, if we define one genus as having eight tentacles, and another as having nine or more tentacles, there can be no confusion between them, for the difference, although slight, is positive and numerical, not qualitative and intergrading. I have not described hydroids which do not produce free-swimming medusae, although I grant it is wholly illogical to admit Podocoryne into a system which excludes Hydractmia, or to include only those species of Stylactis which produce INTRODUCTION. medusae and to exclude those which produce sessile gonophores. Nevertheless this should be clearly understood and must be accepted as an artificial limitation of the work. I have thus attempted to describe only such hydroids as are known to produce medusae, and have endeavored to bring the systematic arrangement of the medusa more nearly into accord with that of the hydroids. A strictly natural system includ- ing both hydroids and medusae can not be constructed, for many of the hydroids remain undetermined. Moreover, dissimilar hydroids (Svm-tjrv>if, StanriJinim may give rise to similar medusae (Sarsia); or the reverse may be the case, as in the medusae of Bongamvillia and Nemopsis, or that of the two sorts of medusa- (Sarsia and Cladoncrna] which may arise from hydroids of Stauridia. These and many other cases of a similar nature interpose a barrier to our attempts to invent a natural system which includes all hydroids and medusa" within its embrace. At present, I believe, we must content ourselves with a compromise between a natural and an artificial arrangement, confiding in the belief that as more and more of the hydroids are discovered it will become correspondingly more possible to arrange the medusae in a natural system. After consultation with Prof. C. C. Nutting we have mutually decided that the promulgation of such ;i system is at present inadvisable. Such a system has, indeed, been proposed by von Lendenfeld, 1884 (Zool. Anzeiger, Bd. 7), but has gained no acceptance. Much confusion has been introduced through the habit, in vogue among marine expeditions, of sending all of the medusa" to one specialist and the hydroids to another. Thus the sessile and the reproductive stages of the same animals are worked upon independently from different view-points by different men. I am inclined to regard the Trachymedusae and Narcomedusa" as being transformed actinutae, for they commonly develop through an actinula larva in which the bell grows out as a collar-like, or intertentacular lappeted expansion from the sides of the body after the tentacles have appeared, and the tentacles of the actinula become those of the medusa. The medusa of the Anthomedusas and Leptomedusae is formed upon a different plan, for the tentacles grow outward from the bell-margin after the bell has developed. I believe, therefore, that the bell of the Trachymedusae and Narcomedusae is not homologous with that of the Antho- medusa and Leptomedusae. It is evident that the entodermal otoliths of the Trachymedusa" and Narcomedusae are not homologous with the ectodermal otoliths of Leptomedusae. Budding and alternation of generations occur in both classes of veiled medusae. I believe that the medusa-shape has been acquired independently in the Trachyhna and Leptolma forms of veiled medusae. The colored plates contained in this volume consist of drawings, from life, of medusae of the Atlantic coast of the United States. The text-figures, on the other hand, are chiefly outline tracings from the illustrations of many authors; and are presented in order to spare the reader the trouble of consulting numerous scattered works of reference. These outline copies of previously-published drawings of medusae were carefully traced from the originals by Mr. Carl Kellner, artist of the Tortugas Marine Laboratory of the Carnegie Institution. Other outline figures are from life, and the majority of these were drawn by the author while studying at Mousehole, Cornwall, England, and at the Naples Zoological Station during the autumn and winter of 1907 and 1908. This book aims to be something more than an old-fashioned systematic treatise, for it attempts to record, if not to review, all works upon the embryology, cytology, oecology, physiology, etc., of all forms coming within the scope of the text. MEDUSAE OF THE WORLD. Many of the medusae are modified more or less profoundly by environmental conditions, and this gives rise to numerous local races, the determination of the relationships between which is all but impossible in the present state of our knowl- edge. Experimental work in this field is in its infancy, yet the few observations of Hallez on Bongainvillia and of Browne in his experiments in maintaining various hydroids under different conditions in aquaria suggest that the results of more extended studies will be of great benefit to the systematist in determining the natural limitations of species. A striking example of the profound effect of environ- mental changes is seen in the experiments of Goldfarb, 1906, upon Eudendrium, wherein he showed that after the regenerative process had entirely ceased in the dark, it could be recalled into activity by an exposure of only five seconds to the daylight. At present the natural classification of the species of such genera as Obclia, Phialidnnn, Etttnna, Bougamvillia, etc., is impossible, and the Linnean system is inadequate to the task of expressing their actual relationships. Indeed, with the exception of the sponges and corals, there is no phylum of the animal kingdom more difficult to classify than the medusae. In a work of this magnitude there must needs be both errors and omissions, and for these I can but present my apologies in advance of their discovery, trusting that all such will soon be discovered and announced, and that science may be more advanced than hindered through the publication of this book. I trust that none of my esteemed contemporaries will feel aggrieved at such criticisms of their labors as may appear in the following pages, for should anyone find cause for such offense, he may console himself in the fact that I am obliged to confess to having found more to criticize and amend in my own previously-published papers than in those of any other living naturalist. ANTHOMEDUS^:. HYDROMEDUS/E OR VEILED MEDUS/E. Medusae with a velum, or diaphragm, which partially closes the marginal opening of the bell. When ripe the sexual products are found in the ectoderm. With a double marginal nerve-ring, one above and one below the velum. Without gastric filaments. Development either direct from actinula larvae or through alternation of generations from hydroids. Order 1. ANTHOMEDUS/E Haeckel, 1879. Hydromedusae with gonads in the ectoderm of the manubrium. Without otocysts. The hydroids are of the Tubularian order. Family No. i, CODONID.&. Anthomedusae with ring-like gonad encircling the manubrium. Four to six simple, unbranched radial-canals. Simple, unbranched tentacles. Subfamily No. i, SARSIANJE. Some or all of the tentacles arise singly, not in clusters, from bell-margin. PACHYCORDYLE, Weismann, i8%$ = Parvanernus ( ?), Mayer, I9°4- Degenerate medusae without tentacles, radial or circular canals. Hydroid: Pachy- cordyle Weismann. AMALTH^EA, Schmidt, 1854. Four rudimentary tentacles, four radial-canals, and a ring-canal. Hydroid: Corymorpha. PENNARIA, Oken, 1815; Goldfuss, i%2O = Globiceps, Haeckel, 1879. Similar to Amalthaa, but the hydroid is Pennana. TRICHORHIZA, Russell, 1906. Medusa resembles Pennaria, but the hydroid is Tnchorhiza. STEENSTRUPIA, Forbes, iS^.6 = Eup/i\s(i, Forbes, i$4.% = Eupliysora, Maas, 1905. Four radially situated tentacles, one of which is long, the other three short. Bell radially symmetrical. Hydroid: Corymorpha. HYBOCODON, L. Agassiz, \%()2 = HybocodonJt-Amphicodon, Haeckel, 1879. One or more well-developed tentacles arise from base of one of the four radial-canals. With rudimentary tentacles at the bases of the three other radial-canals. Bell asym- metrical. Hydroid: H ybocodon Agassiz. MICROCAMPANA, Fewkes, 1889. With one long and five short tentacles, arising at ends of six radial-canals. DlcoDONlUM = Dicodonium + Dincmti, Haeckel, 1879. Two well-developed and two rudimentary tentacles. No meridional lines of nettle-cells over exumbrella. SARSIA, Lesson, i^^.^ = CoJontutn + Sarsia + S'vnJii'tyon, Haeckel, 1879. Four equally developed tentacles with abaxial, ectodermal ocelli. No meridional lines of nettle-cells over the exumbrella. Hydroid: Syncoryne. StauriJiosarsia new subgenus. Medusa similar to Sarsia, but the hydroid is Stuundia. HYDRICHTHYS, Fewkes, 1888. Medusa resembles Sarsia, but there are no ectodermal ocelli upon the tentacle-bulbs. Hydroid: H vJrichthys, Fewkes; commensal or parasitic upon fish. EUCODONIUM, Hartlaub, 1907. Medusa resembles Sarsia, but stomach is mounted upon a gelatinous peduncle. The four tentacles terminate each in a knob-shaped extremity. ECTOPI.EURA, L. Agassiz, 1862 (sens. ampl.). With two or four tentacles. Eight meridional lines of nettle-cells over the exumbrella. Hydroid: Ectopleura. 6 MEDUS.E OF THE WORLD. CORYNITIS, McCrady, 1857. Four knobbed tentacles. Manubrium cruciform in cross-section. Ocelli upon tentacle- bulbs. Hydroid: Syncoryne (Hargitt). SLABBERIA, Forbes, lB^6 = Slabberia + Dif>urena + BathycoJon, Haeckel, 1879. Four knobbed tentacles. Manubrium tubular and encircled by two or more ring-like gonads. Hydroid: Syncoryne. Subfamily No. 2, MARGELOPSIN^E. Four radially placed clusters ot marginal tentacles. No oral tentacles. A ring-like gonad encircles the stomach. Four simple, unbranched radial-canals. Hydroids are pelagic Tubularians, and the medusae arise by budding from their sides. MARGELOPSIS, Hartlaub, 1897. Characters of the medusa are those of the subfamily. Hydroid: Margelopsis, in which the tentacles are disposed in definite circlets. PELAGOHYDRA, Dendy, 1903. Medusa similar to Margelopsis. Hydroid: PelagohyJra. Its tentacles arise irregularly from sides of the hydranth, and are not disposed in definite circlets. Family No. 2, CLADONEMID^E. Tentacles branch dichotomously or complexly, or give rise to a linear series of nematocyst- bearing filaments along their abaxial sides. Gonads ring-like, or segregated upon the inter- radial and adradial sides of the manubrium. Subfamily No. i, PTERONEMINJE. Manubrium without oral tentacles. ZANCLEA, Gegenbaur, l8^6 = Zanclea + Gernmaria, Haeckel, 1879. With two or four tentacles, each of which gives rise to an abaxial row of nematocyst- bearing branches. With meridional rows of nettle-cells upon the exumbrella. No ocelli upon the tentacle-bulbs. No brood-pouch above the stomach. Hydroid: Gemmaria McCrady; Allman. ZANCLEOPSIS, Hartlaub, 1907. Similar to Znticlea, but without meridional lines of nettle-cells over the exumbrella. With ectodermal ocelli upon the outer sides of the tentacle-bulbs. PTERONEMA, Haeckel, 1879. Similar to Zanclea, but with a brood-sac above the stomach. Four tentacles. ELEUTHERIA, Ouatrefages, 1842. Four to six bifurcated tentacles, and an equal number of simple unbranched radial- canals. There is an ectodermal brood-sac above, but not connected with the stomach. The medusa is hermaphroditic and the germ-cells develop in the brood-sac. Hydroid: Clavatella Hincks. MNESTRA, Krohn, 1853; Giinther, 1903. Degenerate medusa parasitic upon Phylhrrhoe. Four to no tentacles, each with an abaxial line of nettle-warts. Four perradial meridional lines of nettle-cells over the exumbrella. Four radial-canals. Throat is blocked by a cavernated mass of entoderm. Subfamily No. 2, DENDRONEMIN^). Manubrium with oral tentacles. CTENARIA, Haeckel, 1879. Two marginal tentacles with abaxial filaments. Four bifurcated radial-canals. Simple oral tentacles. Brood-sac above the stomach. ANTHOMEDUS.E. 7 CLADONEMA, Dujardin, 1843. Four or five bifurcated or eight to ten simple radial-canals. Branched marginal tentacles. Simple oral tentacles. No brood-sac above the stomach. Hydroid: Statin Jin Dujardin. DENDRONEMA, Haeckel, 1879. Similar to ClaJonema, but with branched oral tentacles and with brood-sac above stomach. Family No. 3, OCEANID.S, sensu Vanhoffen. Anthomedusae in which the gonads are segregated and developed upon the interradial or adradial sides of the manubrium. With unbranched marginal tentacles. Mouth with four lips. Subfamily No. i, TIARIN.E. Unbranched radial-canals. Marginal tentacles separate; not grouped into clusters. No oral tentacles. Tentacles hollow. When present the ectodermal ocelli are upon the abaxial sides of the tentacle-bulbs. With the exception of Calycopsis all of the genera have four radial-canals. PROTIARA, Haeckel, i%jq = Halitiara, Fewkes, 1882. Four radially placed, well-developed tentacles. Four interradial gonads with smooth outer surfaces. With or without marginal cirri. External surfaces of gonads smooth. Four cruciform, simple lips. No ocelli on the velar sides of the tentacles. HETEROTIARA, Maas, 1905. Eight or more tentacles. The ring-canal gives rise to blindly-ending centripetal vessels. STOMOTOCA, L. Agassiz, \%()2 = Amf>hinema-\-Stomotoca + Codonorchis, Haeckel, 1879. Two well-developed and many rudimentary tentacles. External surfaces of the adradial gonads are thrown into transverse folds. Hydroid: Pengonimus. DISSONEMA, Haeckel, 1879. Similar to Stomotoca, but the gonads finally migrate outward along the four radial-canals. PANDEA, Lesson, 1843. Four or more tentacles. Gonads four interradial, folded ridges on the sides of the stomach but these gonads are not completely separated in the four principal radii. Hydroid: Dcndroclava ( ? ?). TURRIS, Lesson, 184.3 = Tiara + Turris + Catablema, Haeckel, 1879. Four or more tentacles. Four interradial horseshoe-shaped gonads on the stomach wall. These are composed of more or less fused ridges or network-like swelling. They are completely separated in the four principal radii. Hydroid: Clirculu Wright. CONIS, Brandt, 1834; Haeckel, 1879. Similar to Pandea, but the tentacle-bulbs give rise to abaxially-placed clubs which bear ocelli. CALYCOPSIS, Fewkes, 1882. Sixteen simple, separate radial-canals. Eight transversely folded, adradial gonads. Ring-canal simple. Subfamily No. 2, MARGELINjE. With four unbranched radial-canals. With oral tentacles, or nematocyst-knobs, upon the lips. Tentacles solid. When present the ectodermal ocelli are upon the inner (velar) sides of the tentacles. CYTVEIS, Eschscholtz, iS2() = Cytxis + Cubogastcr, Haeckel, 1879. Four simple marginal tentacles. With simple, unbranched, oral tentacles. PODOCORYNE, Sars, \?>Jtb = Dysmorf>hosa-\-Cytteandra, Haeckel, 1879. Eight or more simple marginal tentacles. With simple, unbranched, oral tentacles. Hydroid: Podocoryne. When present the peduncle above the stomach is solid and gelatinous. MEDUSAE OF THE WORLD. TURRITOPSIS, McCrady, 1856. Eight or more simple marginal tentacles. The entodermal walls of the radial-canals above the stomach are composed ot vacuolated cells forming a peduncle-like base for the stomach. The mouth is studded with a row of nematocyst-bearing knobs. With ectodermal ocelli on the velar sides of the tentacles near their bases. Hydroid: DenJroclava (Brooks). OCEANIA sensu Kolliker, 1853; Gegenbaur (in part) 1856. Medusa similar to Turritopsis, but with solid gelatinous, non-vacuolated peduncle above the stomach. Hydroid: C lava-like. STYLACTIS, Allman, 1864. Degenerate medusae, with four to eight rudimentary marginal tentacles and no oral tentacles. Hydroid: Stylactis. THAMNOSTYLUS, Haeckel, 1879. With two simple, marginal tentacles, and with branched oral tentacles. THAMNITIS, Haeckel, 1879. Four radially placed, simple, marginal tentacles, and branched oral tentacles. LYMNOREA, Peron and Lesueur, iSog — Limnorea + Thamnostoma, Haeckel, 1879. Eight or more simple, marginal tentacles. Branched oral tentacles. BOUGAINVILLIA, Lesson, \$4.T> = Margelis + Lizusa + Hif>pocrene, Haeckel, 1879. With branched oral tentacles. The marginal tentacles are grouped in four radial clusters. All of the tentacles are filiform. Hydroid: Bougainvillia. NEMOPSIS, L. Agassiz, 1849. Similar to Bougainvillia, but each cluster of marginal tentacles consists of a median pair of clavate tentacles flanked by filiform tentacles. Hydroid: Bougainvillia. RATHKEA, Brandt, lS^y = Lizzia + Lizella + Rathkea + Margellium, Haeckel, 1879. With eight clusters of marginal tentacles. Simple or branched oral tentacles. Ring- canal simple. CHIARELLA, Maas, 1897. Sixteen (eight double) clusters of marginal tentacles. The ring-canal gives rise to centrip- etal vessels. Branched oral tentacles. Subfamily No. 3, DENDROSTAURINjE. With branched radial-canals. No oral tentacles. Marginal tentacles arise singly, and are not grouped into clusters. Tentacles hollow. No cirri or marginal clubs. BYTHOTIARA, Giinther, 1903. Four bifurcated radial-canals and a ring-canal. Four interradial gonads. SIBOGITA, Maas, 1904. Four principal radial-canals, which branch complexly. Four interradial gonads. Ring- canal present. NIOBIA, Mayer, 1900. Four principal radial-canals, two of which bifurcate so that six canals reach the circular vessel. Four interradial gonads. The marginal tentacles develop into medusae, and are cast off. PROBOSCIDACTYLA, Brandt, \%Tfi=Dyscannota + Dicranocanna+ Willeta -\-Proboscidactyla, Haeckel, 1879. The four primary radial-canals give rise to simple or branched side branches. No ring- canal. With intertentacular lines of nematocysts upon the exumbrella above the bell-margin. Gonads on the adradial sides of the stomach extending outward along the sides of the four main radial-canals. LEPTOMEDUS.E. 9 WILLSIA, Forbes, 1846. Similar to ProbosciJactyla, but with six or more primary radial-canals. The hydroid belongs to the genus Lar Gosse. Order 2. LEPTOMEDUSjE Haeckel, 1886. Hydromedusae with gonads upon the radial-canals. When present the otoliths are of ectodermal origin. The medusae arise through alternation of generations from Campanu- larian hydroids. Family No. i, THAUMANTIAD^). Leptomedusae without lithocysts. Subfamily No. i, MELICERTIN^. With simple, unbranched radial-canals and an equal number of lips, without oral ten- tacles. Cirri or marginal clubs may or may not be present. THAUMANTIAS, Eschscholtz, \%29 = Tetrtinfmti + T/iiiii>tiiinti(is, Haeckel, 1879. Four or more tentacles. Four radial-canals. No marginal clubs or cirri. Hydroid: T haumantias. LAODICEA, Lesson, i$4$ = Octonema + Laodice, Haeckel, 1879. Four or more tentacles. Four radial-canals, with marginal clubs or cirri. Hydroid: Cuspidella. MELICERTUM, Oken, 1815; sensu L. Agassiz, i%ta=Melicertella+Melicertum, Haeckel, 1879. With eight or more tentacles. Eight radial-canals. No marginal clubs or cirri. Hydroid: Melicerturn Agassiz. M.ELlCER.TlSSA = Mclicertissa + MflicfrtiJnitn, Haeckel, 1879. Similar to Melicertum, but with marginal clubs or cirri between the tentacles. ORCHISTOMA, Haeckel, 1879. More than eight radial-canals. With or without marginal clubs or cirri. TIMOIDES, H. B. Bigelow, 1904. Four radial-canals. The ring-canal gives rise to blindly-ending centripetal diverticula. Numerous tentacles and cirri. Four gonads on the four radial-canals. Stomach mounted upon a peduncle. Subfamily No. 2, POLYORCHIN.E. The radial-canals give rise to branches which end blinJlv and do not connect with the marginal ring-canal. STAURODISCUS, Haeckel, 1879. With four radial-canals, each of which gives rise to two side branches, which end blindly. PTYCHOGENA, A. Agassiz, 1862, 1865. With four radial-canals which give rise to numerous blindly-ending side branches. Gonads leaf-shaped and developed upon the side branches of the radial-canals. POLYORCHIS, A. Agassiz, 1862 to 1865. With four radial-canals which give rise to numerous blindly-ending side branches. Numerous sac-like, sausage-shaped gonads attached to the radial-canals and to their side branches. Ring-canal simple. Bell-margin not cleft into lappets. SPIROCODON, Haeckel, lS^g = Goniomeam/rus, Kirkpatrick, 1903. Similar to Polyorchis, but the ring-canal gives rise to blindly-ending, centripetal branches, and bell-margin is cleft into lappets. 10 MEDUS/E OF THE WORLD. Subfamily No. 3, BERENICINJE. The radial-canals give rise to branches which connect with the ring-canal. CANNOTA, Haeckel, 1879. With four radial-canals, each of which gives rise to two side branches which join the ring-canal. CuviERIA, Peron, 1807 = Berenice, Haeckel, 1879. With four main radial-canals which give rise to numerous non-dichotomous side branches. Gonads on the terminal ramuli of the canals. DICHOTOMIA, Brooks, 1903. With four main radial-canals which divide dichotomously two or more times. The gonads extend outward from the stomach over the canals. DIPLEUROSOMA, Axel Boeck, i$66 = Tetracannota, Mayer, 1900. With three or more main radial-canals which give rise to non-dichotomous side branches. Gonads on the canals adjacent to the stomach. Hydroid: Cuspidella (?). ToxoRCHiS = Toxorchis + ClaJocanna, Haeckel, 1879. Four or more main radial-canals which branch dichotomously one or more times. Gonads on the outer branches of the canals near the ring-canal. NETOCERTOIDES, Mayer, 1900. Eight main radial-canals which branch dichotomously. Gonads extend outward from the sides of the stomach along the radial-canals. Family No. 2, EUCOPID^. Leptomedusaewith lithocysts, and with less than eight radial-canals upon which the gonads are developed. Subfamily No. i, OBELIN^E. With eight adradial lithocysts. Four radial-canals. Stomach without a peduncle. EUCOPELLA, von Lendenfeld, 1883. Degenerate medusae. No tentacles. No manubrium. Branched radial-canals. Hydroid: Eucopella. AGASTRA, Hartlaub, 1897. Degenerate medusae. No manubrium. Simple, unbranched radial-canals. Hydroid: Campanularia ( ?). EUCOPE, Gegenbaur, 1856. Basal bulbs of the tentacles are simple and hollow, and do not project inward into the gelatinous substance of bell. Lithocysts on bell-margin. Hydroid: Campanulana. OBELIA, Peron and Lesueur, 1809. Entodermal cores of tentacles project inward into the gelatinous substance of the bell. Otocysts on bases of tentacles. Hydroid : Obelia. TIAROPSIS, L. Agassiz, 1849. An ocellus with entodermal pigment above each lithocyst. Tentacle-bulbs simple and hollow. Subfamily No. 2, PHIALIN^. With more or less than eight lithocysts. Four to five radial-canals. Stomach without a peduncle. CLYTIA, Lamouroux, \%i2 = Ef>enthesis, McCrady, 1857. Sixteen tentacles alternating with sixteen lithocysts. Four radial-canals. No cirri. Hydroid: Clytia. LEPTOMEDUS.E. 11 PHIALIDIUM, Leuckart, i%$() = 0<:eania, Agassiz, 1862, 1865. Sixteen or more tentacles. More than sixteen lithocysts. Four radial-canals. No rudi- mentary tentacles. No cirri. Hydroid: Campanulina. PHIALUCIUM, Maas, 1905. Similar to Phialidium, but with permanently rudimentary tentacle-bulbs. Hydroid un- known. BLACKFORDIA, Mayer. Numerous tentacles and lithocysts. Entodermal cores of some or all of the tentacles project inward into the gelatinous substance. Four radial-canals. No cirri. No permanently rudimentary tentacles. PSEUDOCLYTIA, Mayer, 1900. Five radial-canals, five lips, five gonads. Numerous tentacles and lithocysts. No cirri. GASTROBLASTA, Keller, \?>?>^=Multioralis, Mayer, 1900. Two or more manubria. No cirri. The medusa propagates by fission. EUCHEILOTA, McCrady, 1857. Four or more closed vesicular lithocysts. Four radial-canals. Marginal or lateral cirri. Hydroid: Campanulina ( ?). MnROCOMA = Phialis + Mitrocoma + Mitrocomiurn + Mitrocomella, Haeckel, 1879. Similar to Eucheilota, but the lithocysts are contained in open folds of the velum. No entodermal ocelli such as are found in Tiaropsis. STAUROPHORA, Brandt, lS^ = Staurostoma + Staurof>hora, Haeckel, 1879. Mouth an open, cruciform, gutter-like slit extending down the four radial-canals. Subfamily No. 3, EUTIMINJE. With eight adradial lithocysts. Stomach mounted upon a gelatinous peduncle. Four radial-canals. SAPHENIA, Eschscholtz, 1829. Two tentacles. Numerous cirri. EUTIMA, McCrady, 1 857 = Eutima + Eutimeta + Octorchis + Octorchandra -\-Eutnnalphcs, Haeckel, 1879. Four or more tentacles. Numerous cirri or marginal warts. Four or eight gonads upon the four radial-canals. Hydroid: Campanopsis (Claus, Brooks). JLwTIMlUM = Eutimium + Octorchi(lium, Haeckel, 1879. Similar to Eutima, but without cirri. Hydroid: Campanulina ( ?) Subfamily No. 4, EIRENINvE. With more than eight lithocysts. Stomach mounted upon a gelatinous peduncle. Four or six radial-canals. PHORTIS, McCrady, 1857. Four or more tentacles. No cirri. Four radial-canals. Hydroid: P/iortis Brooks. IRENOPSIS, Goette, 1886, non Ireniopsis, Mayer, 1894. Six or more tentacles. Six radial-canals. Six lips. Six gonads. EIRENE, Eschscholtz, i%2g= Irene +Irenittm, Haeckel, 1879. Four or more tentacles. Numerous marginal warts or cirri. Four or eight gonads developed upon limited parts only of the four radial-canals. Hydroid: Campan- ulina ( ?) TIMA, Eschscholtz, 1829. Similar to Eirene, but with gonads upon the entire lengths of the four radial-canals. Hydroid: Campanulina ( ?) 12 MEDUS.E OF THE WORLD. Family No. 3, ^EQUORIDjE. Leptomedusae with otocysts, and with eight or more radial-canals. OCTOCANNA, Haeckel, 1879. Eight radial-canals, 45° apart. Eight lips. No ocelli. (Is this a young jEquorea ?) OCTOGONADE, Zoja, 1896. Similar to Octocanna, but the marginal sense-organs have ocelli as well as lithocysts. STOMOBRACHIUM, Brandt, lS^^ = Stomobrachium + Staurobrac/iium, Haeckel, 1879. Eight or more simple, unbranched radial-canals, which arise at equal intervals from the margin of the stomach. Four lips. HALOPSIS, A. Agassiz, 1863, 1865. Radial-canals arise in four groups from the four perradial corners of stomach. Four lips. ^EQUOREA, Peron and Lesueur, i$og = &(juorea + R/iegmatoJes + Mesonema -\-Polycanna, Haeckel, 1879. More than eight simple, unbranched radial-canals which arise separately from the mar- gin of the stomach. More than four lips. Subumbrella smooth, without gelatinous papilla-like protuberances. Hydroid: Campanulina. ZYGODACTYLA, Brandt, 1835; sensu Agassiz, 1862. Similar to jEquorea, but with interradial rows of papilla-like, gelatinous protuberances upon the subumbrella. , Haeckel, 1879. With bifurcated or branched radial-canals which arise at equal intervals from the margin of the stomach. More than four lips. No peduncle. ZYGOCANNULA, Haeckel, 1879. Similar to Zygocanna, but the stomach is mounted upon a gelatinous peduncle. Order No. 3. TRACHYMEDUS.E Haeckel, 1866. Medusae with a marginal velum, and with lithocyst concretions of entodermal origin. With simple uncleft bell-margin. Family No. i, OLINDIADJE. Some or all of the tentacles project from the sides of the bell, above the margin, and have adhesive disks. Gonads linear, sac-like, or folded, and developed upon the four or six radial- canals. The tentacles arise separately and are not grouped in clusters. GONIONEMUS, A. Agassiz, 1862, 1865. All of the tentacles project from sides of bell in a zone slightly above bell-margin. All have adhesive disks. Four radial-canals. Lithocysts external, on bell-margin. No centripetal canals. Development through an attached hydra stage. (Perkins.) CUBAIA, Mayer, 1894. Similar to Gonionemus, but with two sets of tentacles, one arising from the bell-margin and the other set projecting from the sides of the bell, as in Gonionemus. VALLENTINIA, Browne, 1902. Similar to Cubaia, but with lithocysts inclosed within the gelatinous substance of the bell, adjacent to the ring-canal, and on the inner side above the velum. (Is this a young Olindias]) OLINDIAS, F. Miiller, 1861. Similar to / allentmia, but with blindly-ending, centripetal diverticula from the ring-canal. TRACHYMEDUS.K. 13 OLINDIOIDES, Goto, 1903. Similar to OlinJias, but with six radial-canals (two bifurcated and two simple). Six gonads. Four lips. The exumbrella tentacles project at various levels from the sides of the bell. Family No. 2, PETASIDjE Haeckel, 1879. Trachymedusae with tour radial-canals upon which the linear or sac-like gonads are developed. Tentacles without adhesive disks. Four lips. PET ASUS = Pftasus + Dif>etasus + Petas(ita + Pftacli>: uni, Haeckel, 1879. Tentacles arise at equal intervals, not grouped into clusters. No centripetal canals. Free marginal hthocyst-clubs. AGLAUROPSIS, F. Miiller, 1865. Similar to Petasus, but the lithocysts are vesicular, and project from the bell-margin between the tentacles. CRASPEDACUSTA, Lankester, i$%o=LimnocoJium, Allman, 1880. Tentacles arise singly as in Pi-tnsus and Aglauropsis, but the lithocyst concretions are each inclosed in a cavity within the gelatinous substance of the velum on the inner (centripetal) side of the ring-canal. (The medusa lives in fresh water among water- lilies.) The hydroid is devoid of tentacles. MlCROHYDRA, PottS, 1885. Is possibly identical with Limnocodiutn, but the mature medusa is unknown. The young medusa has no lithocysts, and it arises by budding from a minute hydroid which has no tentacles. MJ^OTIAS, OstroumofF, 1896. Tentacles arise at equal intervals, not in clusters. Numerous centripetal, blindly-ending canals arise from the ring-canal. GOSSEA, L. Agassiz, 1862. Tentacles grouped into clusters. No centripetal canals. Lithocyst concretions free or inclosed. Family No. 3, LIMNOCNIDIDjE. Numerous hollow tentacles which project singly, not in clusters, from the sides of the bell in a zone slightly above the margin. Tentacles without adhesive disks. Numerous inclosed lithocysts on the exumbrella side of the velum. Mouth a round opening. Gonads developed diffusely in the ectoderm of the stomach-wall. Four (occasionally five or six) radial- canals. Medusa-buds arise from the sides of the stomach, and are set free. LIMNOCNIDA, Giinther, 1893. Generic characters are those of the family. The only known species is /,. tanganjicd from the fresh-water lakes of Central Africa, and the Niger river. Family No. 4, PTYCHOGASTRIDJE. Numerous more or less isolated clusters of tentacles, some of which bear adhesive disks. Numerous free lithocyst-clubs. Eight radial-canals. Four lips. Stomach eight-lobed. These stomach-lobes are in the radii of the radial-canals, and are bound to the subumbrella by means of eight mesenterial partitions. The gonads are upon the eight stomach-lobes, and each is more or less divided by the mesentery so there may be eight double (sixteen) gonads. PTYCHOGASTRIA, Allman, iSfi^Pcctyllis + Pectis + Pectanthis, Haeckel, 1879. The generic characters are those of the family. Family No. 5, TRACHYNEMID^E. Trachymeduss with eight simple radial-canals upon which the gonads are developed. No mesenterial partitions in the subumbrella. Tentacles without adhesive disks. Ring- canal simple without centripetal branches. 14 MEDUSA OF THE WORLD. Subfamily No. i, RHOPALONEMINjE. Trachynemidae in which the stomach lacks a peduncle. RHOPALONEMA, Gegenbaur, iS^6=Trachynema (young medusa), Gegenbaur, 1854 = Trachynema + Rhopalonema + Marmanema, Haeckel, 1879. With eight well-developed radial tentacles, and eight or more small cirrus-like or club- shaped interradial tentacles. All tentacles arise in a single row. Eight gonads localized on the eight radial-canals. Four lips. SMINTHEA, Gegenbaur, 1856. Similar to Rhopalonema, but with only eight tentacles, one at the foot of each of the eight radial-canals. HOMCEONEMA, Maas, i8g3 = Colobonema, Vanhoffen, igo2 = lsonema (in part), Maas, 1906. Similar to Rhopalonema, but the tentacles are all of one sort. No small club-shaped or cirrus-like tentacles. Four lips. PANTACHOGON, Maas, 1893 (sens. ampl.). Gonads not localized as in Homceonema and Rhopalonema, but developed diffusely over the radial-canals. Four lips. HALICREAS, Fewkes, i$82 = Halicreas + Haliscera, Vanhoffen, 1902 = Isonema (in part), Maas, 1906. The mouth is a simple round opening, without four lips. (In all known species the radial-canals and ring-canals are very broad and flat.) Wart-like protuberances may be present upon the sides of the exumbrella. Radial tentacles large, interradial, small. Tentacles arise in a single row. BOTRYNEMA, Browne, 1908. Similar to Halicreas, but the tentacles are grouped in linear clusters in a single row around the bell-margin. CROSSOTA, Vanhoffen, 1902. The tentacles arise in several rows from the bell-margin. Mouth with four lips. Subfamily No. 2, AGLAURINjE. Stomach mounted upon a peduncle. AGLAURA, Peron and Lesueur, 1809. Eight gonads upon the peduncle above the stomach. Sexes separate. Development direct. AGLAmHA = /fglantha + 4glisi:ra, Haeckel, 1879. Eight gonads upon the subumbrella, or at the turning points of the eight radial-canals between the peduncle and the subumbrella. Sexes separate. AMPHOGONA, Browne, 1904. Similar to Aglantha, but medusa is bisexual, four of gonads being male, and four female. STAURAGLAURA, Haeckel, 1879. Four gonads, one upon each alternate radial-canal. PERSA, McCrady, 1857. Two gonads on two of the radial-canals, 180° apart. The six other radial-canals are sterile. Family No. 6, GERYONIDjE. Trachymedusae with four or six radial-canals upon which the flat, expanded, leaf-like gonads are developed. Stomach mounted upon a gelatinous peduncle. The ring-canal gives rise to blindly-ending centripetal canals. LIRIOPE, Lesson, i%^ = Linantha -\-Lirwpc + Glossocodon -\-Glossoconus, Haeckel, 1879. Four radial-canals. Four gonads. Four lips. With four primitive, solid, radial, and four solid interradial, and four hollow, flexible, radially-placed tentacles; all twelve of which may be found upon the medusa at one and the same time. Development direct through a free-floating, actinula-like larva. GERYONIA, Peron and Lesueur, i8og = Geryones + Geryonia + Carmaris + Carmarina, Haeckel, 1879. Similar to Liriope, but with six radial-canals, six gonads, six lips, etc.; instead of four. NARCOMEDUS.E. 15 Order No. 4. NARCOMEDUS^ Haeckel, 1879. Veiled medusae with bell-margin cleft into intertentacular lappets. With free lithocyst- clubs, containing concretions of entodermal origin. These medusx develop from actmula larvae either directly or by budding. The bell grows outward from the sides ot the body of the actinula, or the medusa-bud, leaving the tentacles stranded in the partially closed-over clefts between the lappets of the bell. The Narcomedusae are thus medusiform, actinula-like animals, the bell of which is not homologous with that of the Anthomedusae or Leptomedusae. Family No. i, SOLMARIDjC. Narcomedusae in which the outer margin of the stomach is plain, entire, and without peripheral stomach-pouches. Saccules may, however, arise from the subumbrella floor of the stomach. o/)'fo//>a (young) + Sohnaris, Haeckel, 1879. Without subumbrella saccules. Gonad is a simple annulus in ectoderm of subumbrella floor of stomach. PEGAJXTBA=Pegasia+Polyxenia+Pegantha+SoImoneta (in part), Haeckel, 1879. With out-pocketings on the subumbrella floor of the stomach. The gonads are developed in these subumbrella saccules. Family No. 2, jEGINID^E, sens. ampl. Narcomedusae in which the central stomach gives rise to simple or cleft marginal out- pocketings in the radii of the tentacles. CUNANTHA, Haeckel, 1879. Four tentacles. Four peronial strands in the tentacular radii. Four simple, uncleft, peripheral stomach-pouches in the radii of the tentacles. This "genus" is prob- ably only a young stage of JEgina. JEciNA, Eschscholtz, i$2g = Cunarcha + £gina + SolmunJus, Haeckel, 1879. Four tentacles. Four peronial strands. Four cleft ( = eight peripheral) stomach-pouches, outer margins of which may be still further divided. SoLMUNDELl.A=dlgi>iella + SolmunJella, Haeckel, 1879. Two tentacles. Four peronial strands. Four cleft ( = eight peripheral) stomach-pouches. An apical (exumbrella) sense-organ is present in larva, but does not persist in adult. Derived from jEgina by the disappearance of half ot its tentacles. HYDROCTENA, DawydofF, 1903. Two tentacles. No peronial strands. Two simple, uncleft stomach-pouches in the tentacular radii. There is an apical (exumbrella) sense-organ consisting in a ciliated pit containing two lithocyst-clubs. A median axial canal extends upward from the stomach to the bottom of the sensory pit. CUNOCTANTHA, Haeckel, 1879. Eight tentacles. Eight peronial strands. Eight simple, uncleft stomach-pouches in the tentacular radii. unoctona + ^Eginura, Haeckel, 1879. Eight tentacles. Eight peronial strands. Eight cleft ( = sixteen peripheral) stomach- pouches. The outer margins of these pouches may be still further divided so as to give thirty-two marginal pouches. S, Brandt, 1835. Four tentacles. Eight peronial strands. Eight cleft ( = sixteen peripheral) stomach- pouches. Derived from jEginura by the disappearance of half of its tentacles. CUNINA, Eschscholtz, 1829. Nine or more tentacles, and an equal number of peronial strands. Peripheral stomach- pouches simple, uncleft and equal in number to the tentacles, in the radii of which they are developed. With otoporpae above the sense-clubs. 16 MEDUS.E OF THE WORLD. SOLMISSUS, Haeckel, 1879. Similar to Cunina, but without otoporpae. CvNlSSA = Cnnissa + ^EginoJorus, Haeckel, 1879. Nine or more tentacles, and the same number of peronial strands. Peripheral stomach- lobes twice as numerous as the tentacles, being cleft in the tentacular radii. jEciNODiscus, Haeckel, 1879. Eight tentacles, sixteen peronial strands. Sixteen cleft ( = thirty-two peripheral) stomach- pouches. MEDUS/E MILLEPORIN^;. Under this heading we may place the degenerate, free-swimming medusae of Millepora. They have no velum and are thus separated from the veiled medusae or Craspedotae. Not only is the velum absent, but the medusa is also devoid of a peripheral canal system and of marginal tentacles. The medusae Milleponna? and Craspedotae are doubtless derived from a common ancestral phylum, but have departed widely, one from the other, so that the Craspedotae are constantly characterized by a diaphragm-like membrane, or velum, which partially closes the opening of the bell-cavity at the tentacular margin; whereas this structure is absent in the Milleporinae. The only known forms of Medusae Milleporinae are those of Millepora. Millepora alcicornis (Medusa). Millepora (medusa*), HICKSON, 1900, Proc. Roy. Soc. London, vol. 66, p. 3, figs. i-io. — DUERDEN, 1899, Journal of the Institute of Jamaica, March, 1899. — HICKSON, 1906, Cambridge Natural History, vol. I, Coelenterata, p. 259, fig. 129. Each medusa lies in an ampulla, or cavity, of the corallum, and is attached by a narrow stalk to the innermost part of the wall of the cavity. The bell is 0.4 to 0.6 mm. in diameter and is devoid of radial or circular canals or velum. It consists of a median lamella of entoderm covered on the exumbrella and subumbrella sides by an ectodermal epithelium. There are no tentacles, but instead there are 4 or 5 swollen masses of nematocysts 90° or 72° apart, near the bell-margin, but projecting from the sides of the exumbrella. The manubrium is greatly swollen, and fills the greater part of the bell-cavity. A mouth may (or may not ?) be present. There are I to 5, usually 3 or 4, large ova in the ectoderm ( ?) of the manubrium. The central entodermal cavity of the manubrium consists of an axial chamber which often gives rise to 4 perradial pouches which project into the entoderm of the manubrium, and end blindly. In some medusae these pouches do not exist, in other specimens there are but 2 or 3, but probably the most common condition is that of 4 pouches 90° apart. The fully-developed ova occupy positions alternating with the pouches. Dr. Duerden observed that these medusae are set free and swim slowly about with infrequent feeble pulsations. Soon after liberation the ova begin to be discharged into the water and the medusa dies after 5 or 6 hours of life, having discharged all of its eggs. The Pacific millepores also produce medusae (see Hickson, S. J., 1891, Quart. Journ. Micros. Sci., 1898; Proc. Zool. Soc. London; and Philosoph. Trans. Roy. Soc. London, B, vol. 179). OKOKIf A.Vmn.MKDI S.K. 17 VEILED MEDUS/E. MEDUSAE CRASPEDOT^E Gegenbaur, 1856. Cr\ftacar/iir, ESC'HSCHOLTZ, 1829, Syst. drr Acalc'phac. Gymnopthalmeet FORBES, 184^, British Naked-eyed MeJuvr. CnispeJala, GEC-.ENBAI'R, 1856, Zeit. fiir wisscn. Zool., Bd. X, p. 217. Craspcdotf, HAECKEL, 1879, Syst. der Medusen. — MAAS, 1X9}, Ergi-h. ilcr Plankton-Expedition] Bd. 2, K.c. CHARACTERS OK THK VKII.ED MEDUSJE. Medusae with a velum or diaphragm which partially closes the marginal opening of the hell-cavity; with ectodermal gonads (i. e., the sexual products u'lifn ripe are commonly found in the ectoderm). Without gastric filaments, \\irh a douhle marginal nerve-ring, one ahmi- and one below the velum. Development either direct or through alternation of generations from hydroids. Order ANTHOMEDUS^E Haeckel, 1879. Oceanitit (in part), GEUENBAUR, 1856, Zeit. fur wissen. Zool., Bd. 8, pp. 218, 219. Tubularix (in part), ACASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 337. AnthomeJustr, HAECKEI., 1879, System der Medusen, p. 3. — VANHOFFEN, 1891, Zoologischer An/eiRtr, Bd. 14, pp. 439, 442.— MAAS, 1905, Craspedoten Medusen der Siboga Expedition, p. 5; 1897, Mem. M. C. Z. at Harvard Coll., vol. 23, p. 9. — HARTLAUB, 1892, Nachrichten kgl. Gesell. \Vissenschaftcn Gottingen, p. 17; 1897, Nordisches Plankton, Nr. 12, p. 4. — HARGITT, 190^, Bull. U. S. Bureau of Fisheries, vol. 24, p. 29. CHARACTERS OF THE ANTHOMEDUSyE. Hvdromedusae in which the gonads are contained within the ectoderm of the manubnum. There are no marginal otocysts or sensory clubs. The hydroids are of the Tubulanan order. We may distinguish three families: (1) CodoniJif with simple tentacles, and with the gonad in the form of one or more rings encircling the manubrium. No oral tentacles. (2) CladonemiJtr with feathered or branched marginal tentacles. Gonads ring-like, or more or less separated. With or without oral tentacles. (3) OceaniJir with gonads confined to the interradial or adradial sides of the manuhnum and separated one from another in the meridians of the principal radii. With or without oral tentacles. With unhranched marginal tentacles. The bell in the Anthomedusae is without marginal lappets, and usually dome-shaped. The tentacles arise from the bell-margin, not from the sides of the bell. The velum is simple and annular, and is provided with circular muscles serving to produce the periodic con- tractions of the bell. The hell-margin is simple and entire, and there are no otocysts, otohth- clubs, or club-shaped sense-organs. Marginal cirri rarely present. In the young medusa the exumbrella is more or less besprinkled with nematocysts, but these usually disappear or become less conspicuous in the adult; although definite nematocyst tracts often persist over the exumbrella, this being far more commonly seen in Anthomedusas than in other orders of Hydromedusae. The tentacles usually arise singly from the bell-margin, and are usually simple and unbranched. Ectodermal ocelli are often found upon the tentacle-bulbs, and Romanes showed that in Sarsia these subserved a visual function, and that the medusa was strongly attracted by rays between the red and violet. The main shafts of the tentacles are thickly covered with nematocysts, which may be mounted upon filaments or converted into adhesive organs, as in the Cladonemidae. The tentacle-bulbs are hollow, and connected with the gastrovascular system ot the medusa. The radial-canals are usually simple, but in the Tiarinae they often give rise to short, blindly-ending diverticula, which may be glandular in function, (ilandular swellings are found in the walls of the radial-canals of L\tnno- codon, Slabberia, and Sarsia, and in the Oceanidae in the genera Cytieis, Dysmorphosa, Bou- gainvillia, Rtithkea, and in the Williadi. In some of the Williadi the medusa-buds are borne upon stolons which arise either from the radial corners of the stomach, or from the forks of the radial-canals. In the case of Sarsia and Hybocodon the budding medusae develop as in hydroids, the entoderm of the parent medusa forming the entoderm of the budded medusa, and the ectoderm of the bud being formed from the ectoderm of the parent. In Rathkea, Chun, 1895, discovered that the budding medusa is formed out of the ectoderm of the parent, although a connection is finally established between the entoderm of the bud and that of the parent a short time before the hud is set free. In Bougainvillia tuobe, on the other hand, I find that the budding medusa is formed entirely from the ectoderm of the parent, no con- nection being established between the entoderm of the bud and that of the parent. In the genus Niobia the tentacle-bulbs develop into medusae and are set free. The majority of the Anthomedusae undergo a considerable development while swimming freely in the water. In some cases, however, the medusae may, at times, become mature and even discharge their genital products while still attached to the hydroid. This is seen in Pennaria, Podocoryne, Sarsia, and Stylactis. Among the most short-lived medusae are those of Pachycordyle, which have neither tentacles, marginal sense-organs, nor radial nor circular canals. All of the Anthomedusae are inhabitants of salt water. They are rare in the open ocean far from land, but are abundant along coasts, especially along continental shores, and many of them thrive in harbors where the water may be more or less brackish. They appear to be the simplest, and phylogenetically the oldest, of the Hydromedusae. ORDER ANTHOMEDlS.i:. 19 Family CODONIDjC Haeckel, 1879, sens, amend. Sarsiadat (in part), Founts, 1848, British Naked-eyed Medusa;, p. 55. Sarsiada+ Tubularidtf, McCRADY, 1857, Gymn. Charleston Harbor, p. 21. Sarsiadtf (in part)-t- Tubularidx+ Pennaridj: (in part), AGASSIZ, L., 1862, Cont. Nat. Hist. (-'. S., vol. 4, pp. ^9, 542. SarsiadtE+ Orthocorynidx + Tubulands + Pennanda, AGASSIZ, A., 1865, North Amer. Acalephx, pp. 175, 183, |S6, 189. Codonidz, HAECKEL, 1879, Syst. der Medusen, p. 9. — VANHOFFEN, 1891, Zool. Anzeiger, Bd. 14^.442. — HARGITT, 1904, Bull. Bureau of Fisheries U.S., vol. 24, p. 29. — HARTLAL-B, 1907, Nordisches Plankton, Nr. 12, pp. 5, 6. Codonina+ Cor\nidurena + Bathvcodon, HAECKEL. Similar to Sarsia, but with two or more ring-like gonads upon the manubrium. Hydroid: S\ncor\ne. SUBFAMILY No. 2. MARGELOPSINJE. With 4 radiallv-placed clusters of marginal tentacles. No oral tentacles. Gonads ring-like, and encircling the manubrium. MargelopsiSy HARTLAUB, 1897. Marginal tentacles are grouped in 4 radially-situated clusters. Gonad ring-like, and surrounds manubrium. No oral tentacles, mouth is a simple round opening. Medusae develop by budding from a free-floating hydranth, A/drgr/o/fj/i. This interesting genus recalls the Bougainvillidi in its radially situated clusters of marginal tentacles. It resembles the Codonidts in its ring-like gonad, and in the absence of prominent lips and oral tentacles. Pelagohydra, DENDY, 1903. Medusa similar to Margelopsi* but hydroid is Pelagohydra, and differs from hydroid of Margelopsn in that tentacles arise at irregular intervals from the sides of the hydranth and are not arranged in definite verticils as in Margelopsis. Hydroid is pelagic. PLATE i. Fig. I. PaehycorJyle degeneratus, male. Nassau Harbor, Bahama Islands, July 19, 1903. Fig. 2. Budding hydranth of Pennaria tiarella with female medusa-bud still attached. Agassiz Laboratory, Newport, Rhode Island, July 5, 1895. Found attached to eel grass in shallow water. Fig. 3. A recently liberated male medusa of Pennaria tiarella. Agassiz Laboratory, Newport, Rhode Island, July, 1895. Fig. 4. Hydroid stock of Pennaria tiarella, natural size. Agassiz Labora- tory, Newport, Rhode Island, July, 1895. Fig. 5. Pennaria tiarella. From the coral reef at Tortugas, Florida, May 7, 1905. fig. 6. Steenstrupia vtrgulata. From a drawing made from life by Dr. Alexander Agassiz at Nahant, Massachusetts, August 21, 1862. Fig. 7. Steenstrupia rubra, male. Oregon Inlet, Pamlico Sound, North Carolina, November 12, 1904. Fig. 8. HyhoeoJon forbesii. Tortugas, Florida, May 25, 1905. Fig. 6, from a drawing by Dr. Alexander Agassiz Figs, i to 5, 7, 8, from life, by the author. AXTHOMKIHS K I'A( IIV( -iililiVLK. '_' I DESCRIPTION OF GENERA AND SPECIES OF ANTHOMEDUSjE. Genus PACHYCORDYLE Weismann, 1883. Pachycordylt, WEISMANN, 1883, Entstehung Seiualzellen Hydromedusen, pp. 87, 217. HAKI.II r, 1404, Mitth. Zool. Station Neapel, BJ. |6, p. 553. Paminrmus, MAYER, 1904, Mem. Nat. Sci. Museum Brooklyn Institute Arts and Sti., v.il. i, No. i, p. 6. GENERIC CHARACTERS. Codonidae without tentacles, radial-canals, or circular vessel. Manubrium surrounded by a ring-like gonad. The hydroid-stock is Pachycordyle. Except the medusas of Millepora, these are the most degenerate and short-lived of the free-swimming Hydromedusae. They are even more degenerate than are the medusae of Corymorpha and Pennaria, and may be compared with Eucopflla (R. von Lendenfeld, 1883, Zeit. fur wissen. Zool., Bd. 38, p. 497) and Agastra (C. Hartlaub, 1897, Wissen. Meeresunter- such. Biologisch. Anstalt auf Helgoland, Neue Folge, Bd. 2, Heft i, Abt. 2, p. 504, taf. 22, figs. 5, 8 10). In these last-named medusae we find neither manubrium nor marginal tentacles, hut there are 8 otocysts and a velum, and the radial and circular vessels are well developed. Pachycordyle weismanni Hargitt. Pachvcorii\lf lutnmannt, HAROITT, 1904, Mittli. Zool. Station Neapel, Bd. 16, Heft 4, p. 553, plate 21, figs. 1-8. ( ?) Pachyconlyle napolilana, WEISMANN, 1883, Die Entstehung der Seiualzellen bei den Hvdromedusen, Jena, pp. 87, 217. Medusa pyriform, 2 mm. high, 1.3 mm. wide. Tentacles and marginal sense-organs lacking. No radial-canals. Ring-canal a mere fissure with vestiges of an entodermal linin» near the margin. Velum narrow, with a small opening. Manubrium large, conical, and with- out a peduncle. Ripe ova are in the entoderm, and are discharged very soon after medusa is liberated. Mouth lacking. Manubrium orange or dark-brown, other parts colorless. The medusa swims with a short, jerky motion, but lives only one or two hours. The hydroid is found in the Bay of Naples growing upon the shell of Fusus rostratits. The colony arises from a delicate, reticulated hydrorhiza. Hydrocaulus sparingly branched, 3 to 8 mm. high. Perisarc dull yellowish-brown, not extending beyond base of the hydranth. Hydranths club-shaped, with subconical hypostome. 8 to 16 irregularly arranged filiform ten- tacles, delicate and thread-like when expanded. Body of hydranth orange or reddish, hypostome whitish. Not more than 2 or 3 medusa-buds are borne on the side of the stem of each budding polyp. Occasionally the medusa-buds develop on the side branches, more commonly on the main stems. The ova originate in the entoderm where they remain until discharged into the water from the manubrium of the medusa. This species may possibly be the female torm of VVeismann's Pachycordyle napolitana. On Weismann's hydroid, how- ever, there were no free medusae, only sessile gonophores. All of Weismann's specimens were males, while Hargitt's were females, and it is possible, as Hargitt states, that the females only give rise to free-swimming medusae. Pachycordyle degeneratus. Plate I, fig. I. Paroanemu* degtneretuit MAVFR, 1904, Memoir-. N.it. Sn. Museum Rrooklvn Institute of Art^. and Sci., vol. i. No. i, p. fi, plate ',. "H- "• Bell thin-walled, about 0.75 mm. high and 0.3 mm. in diameter. Bi-ll-walls quite rigid, velum powerful and well developed. There are neither tentacles, radial-canals, circular vessel, nor marginal sense-organs. Manubrium spindle-shaped, and about a third as lon» as height of bell. Fluids within the stomach-cavity are maintained in rapid motion, appar- ently through the action of cilia. Near aboral end of bell is a deep conical cicatrice which apparently marks the place of last connection between the medusa and its hydroid stock. Bell is translucent and milky in color, while manubrium is cream-colored. Only 5 specimens, all males, were found in Nassau Harbor, Bahamas, on the nights of July 18 and 19, 1903. 22 MEDUS/E OF THE WORLD. They swam actively in arcs of circles, but all died early in the morning although maintained in large glass dishes filled with pure sea-water. They appeared to be mature, for sperm was discharged constantly from the sides of the manubrium. The hydroid is unknown, and possibly the medusa may not belong to the genus Pachy- corJyle, though in the medusa stage it conforms with the generic character of the medusae which are set free from Pachycordyle iveismanni of Naples. Genus AMALTH^EA Schmidt, 1854. Corvinorplia (hydroid), SARS, M., 1835, Beskriv og Jagttagelser, p. 7. Corymorpha (medusa and hydroid), STEENSTRUP, 1854, Vidensk. Meddel. Nat. For. Kjobenhavn, p. 46. Amahhxa (medusa), SCHMIDT, 1854, Handatlas vergl. Anatomie, p. 13. — HAECKEL, 1879, Syst. der Medusen, p. 38. Amallhiza, ALLMAN, 1872, Monog. Tubularian Hydroids, p. 393. — LOMAN, 1889, Tijdschrift, Nederland. Dierk. Vereen, Ser. 1, Deel. 2, p. 270. Corymorpha, HARTLAUB, 1905, Zoolog. Jahrb., Abth. Syst., Suppl. 6, p. 543; 1907, Nordisches Plankton, Nr. 12, p. 75. GENERIC CHARACTERS OF THE FREE MEDUSA. Codonidae with 4 rudimentary tentacle-bulbs, 4 radial-canals, and a ring-canal. Hydroid is Corymorpha, but distinguished by the character of its medusae. The majority of species of Corymorpha hydroids do not give rise to free-swimming medusae. Hydroid of Arnalthtta might therefore be called Amalthaa. The medusae of Amalthcra resemble those of Pennaria, but the manubrium is usually longer, and extends beyond the velar opening. Hartlaub, 1907, includes the medusae of Steenstrufia, Euphysa, and Amalthaa in the genus Corymorpha, for they all arise from identical hydroids; while the medusae differ as follows: Steenstrufia, 3 short, and I long tentacle, and with an apical projection and axial canal above the stomach. Euphysa, similar to Steenstrufia, but without an apical projec- tion or axial canal. Amalthxa with 4 rudimentary tentacles. Amalthrea sarsii Allman (Medusa only). Corymorpha sarsii, STEENSTRUP, 1854, Vidensk. Meddel. Naturhist. For. Kjobenhavn, p. 48. — BONNEVIK, 1898, Zeit.fiir wissen. Zool., Bd. 43, p. 476. — HARTLAUR, 1907, Nordisches Plankton, Nr. 12, p. 86, fig. 82. Amatthtea sarsi:, ALLMAN, 1871, Monog. Tubularian Hydroids, p. 393. — HAECKEL, 1879, Syst. der Medusen, p. 38. ( ?) Arnaltluea amtebigera, HAFCKEL, Ibid., p. 38, taf. I, figs. 10, ll. It is not certain that this hydroid gives rise to free-swimming medusae, though when arti- ficially set free the medusae swim about actively. The bell of the attached medusa-bud is elongate with a subconical basal apex and with fairly thick bell-walls. It is 4 mm. high. There are usually 4 equally developed rudimentary tentacles, but occasionally one of the tentacles is longer than the others. Velum well developed. 4 straight, slender radial-canals. Manubrium spindle-shaped. Mouth a round opening studded with nematocysts. In the male the manubrium projects one-third its length beyond velar opening, but in the female it is shorter and the mouth is at the level of velar opening. Ova are few in number. When immature they are amoeboid, but when older they become spherical and project over the surface of the gonad, attached by short pedicels. The gonad encircles the entire manubrium. Manubrium straw-yellow, tentacle-bulbs light-red. Found oft coast of Norway. Hydroid: Corymorpha sarsn. Amalthaea uvifera Schmidt. Amalthira uvifera, SCHMIDT, 1854, Nordisches Plankton, Nr. 12, p. 88, fig. 83. Corymorpha uvifera, HARTLAUB, 1907, Handatlas der vergleich. Anatomie, p. 13, taf. 9, fig. 2. This medusiform gonophore is not known to be set free. It is borne upon branched stolons which arise from the sides of the polypite above the basal circlet of long tentacles. Each stolon is tree-like and gives rise to 30 to 40 grape-like medusa-buds, so that each hydroid gives rise to more than 100 buds in various stages of development. In the medusa-bud (when about to be set free ?) there are 4 large globular, rudimentary tentacle-bulbs. The bell is higher than a hemisphere, with walls thin at apex. Manubrium ANTHOMKDUS.K— AMAI.TII.KA, I'KN \.\HI.\. -'.', spindle-shaped, as long as the depth of the bell-cavity. The hydroid is C.or\inhn uvifern, found at Loppen Island, ahout 10 miles from Hammerfest, at a depth of about I fathom. Amalthaea vardoensis Loman. Amahht Allman, 1872. I believe the American " Penmn-in tinn-lln" to be closely related to P. Jiiliilm. The only difference appears to be that the terminal ramuli in P. disticha are ringed through- out, whereas in P. tiarella they are usually ringed only at base and summit, although I have seen an occasional one ringed throughout in the American hydroid. (See VV. S. Wallace, 1908, Year Book of the Carnegie Institution.) In the European hydroid, P. Jisticha, the stems become about 150 to 175 mm. high. The main stem is slightly zigzag and with a uniform growth-curve from base to summit. There are about forty side branches, regularly alternate. Perisarc annulated at the origins of the branches and on the ultimate hydranth-bearing ramuli. Hydranths flask-shaped, with a single verticil of about 10 to 13 basal filiform tentacles each about I to 2 times as long as the body of the hydranth, and each ending in a blunt, slightly swollen tip. About 20 short, stiff, knobbed tentacles, irregularly arranged in 3 verticils, arise from the sides of the hydranth above the basal verticil of tentacles. The medusa-buds are similar to those of Pennaria tiarella and are without ectodermal ocelli upon their tentacle-bulbs. The medusa? usually wither upon the hydroid without being set free, but this often occurs also in P. tiarella, especially in the warm water of Florida. Weismann, 1883, found that the germ-cells originate in the ectoderm of the inner layer of the bell-nucleus and do not wander from their place of origin, becoming mature in the free medusa, or when the medusa-bud is ripe. Very elaborate studies upon regeneration, regulation, and restitution in injured colonies were carried out by Cast and Godewski, 1903. This hydroid is found in the Mediterranean. Pictet, 1893, found it at Amboina, Malay Archipelago. It occurs at Naples, Italy, from May to November. Pennaria tiarella McCrady (American). Plate I, figs. 2-5. REFERENCES TO THE AMERICAN HYDROID. G/obiceps tiarella, AOASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 344. — AVER, 1852, Proc. Boston Soc. Nat. Hist., vol. 4, p. 193. — HAECKEL, 1879, Syst. der Mejusen, p. 39. Pennarin tiarella, AGASSIZ, A., 1865, North. Amer. Acal.,p. 187, figs. 311-315. — NUTTING, 1901, Bull. U. S. Fish Commission for 1899, vol. 19, pp. 337, 374, figs. 14, 83. — HARGITT, 1900, Amer. Naturalist, vol. 34, p. 387, plates 1-4, 36 figs.; Bull, of the Bureau of Fisheries U. S., for 1904, vol. 24, p. 32, plate 3; 1904, Archiv. fur entwickrlungs-mech. organ- ism, Bd. 18, p. 453, taf. 24-28; 1902, Amer. Naturalist, vol. 35, p. 31 1, figs. 8, 9; p. 597, fig. 36; 1899, Biol. Bulletin Woods Hole, vol. i, p. 35-40, 6 figs, (grafting eiperiments); 1900, Science, New series, vol. 12, p. 340; and 1901, Biol. Bulletin Woods Hole, vol. 2, p. 223 (variations of hydroids and medus.T.) — MCCRADY, 1857, Gymn. Charleston Harbor, p. 51. — SMALLWOOD, 1899, American Naturalist, vol. 33, p. 861, 7 figs, (histology). — HARTLACB, 1907, Nor- disches Plankton, Nr. 12, p. 72, figs. 68-70. — GOLDFARB, 1906, Journ. Experimental Zool., vol. 3, p. 148 (regeneration). Pennaria liarclla=(P. svmmetrica, CLARKE), CONGDON, 1907, Proc. American Acad. Arts and Sci., vol. 42, p. 464. Pennaria, j/>., THACHER, 1903. Biol. Bulletin, vol. 4, p. 96. I'tnritiria gibbosa, AGASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, pp. 278, 344; vol. 3, plate 15, figs. I, 2. Halcord\Ie tiarella, ALLMAN, i87i,Monog. Tubul. Hydroiils, p. 369. Kuforyne elegant, LEIDV, 1855, Marine Invert. N. J. and R. I., p. 4, plate 10, figs. 1-5. THE AMERICAN PENNARIA. Medusa. — The bell is about 2 mm. in height, and is ellipsoidal, being higher than it is broad. Bell-walls very thin, flexible, and much distorted by the remarkably large ova, which are situated within the ectoderm of the manubrium and often fill the entire cavity of the bell. There are 4 small, rudimentary tentacle-bulbs, without ocelli, I at the base of each radial- canal. Radial-canals straight and quite broad. Velum wide and powerful. Manubrium of male more slender than that of female, the latter being usually greatly distended with 4 or 5 large ova. Several ova are often set free into the water before the medusa is liberated from the hydroid stock. The medusa is commonly mature at the time of its liberation, and it is probable that it does not usually survive for more than a few hours, though Dr. A. Agassiz has maintained them alive for several weeks. The entoderm of the manubrium is rose-pink, and there are a number of deep-pink blotches in the entoderm of each radial-canal. The entoderm of the tentacle-bulbs is pearly-white, as are also the eggs within the manubrium. These colors vary considerably in hue and may be almost white. 2fi MEDTS.E (>K THE WOULD. Hydroid. — The hydroid is very abundant upon eel-grass, seaweeds, stones, or wharves, below low tide. The stems arise from a ramifying stolon. They attain a height of 100 to 125 mm. The main stems branch alternately, the longest and oldest side branches being found nearest the base of the stock. The side branches give rise to simple or slightly branched ramuli from their upper sides. These ultimate ramuli are annulated at base with 5 to 6 rings, and the main stem and primary branches are annulated beyond each branch. The stems are covered with a chitinous, horny perisarc. The polyp-heads are flask-shaped, and the mouth is situated at the ex- tremity of a long, slender, conical throat-tube. There are 2 or 3 verticils of oral tentacles, each row being composed of 5 to 7 short, stiff tentacles, each terminating in a knob-shaped cluster of nem- atocysts. Besides these there is a single circlet of 12 to 16 long, flexible tentacles near the proximal base of the polypite. The medusa-buds develop upon the sides of the polypites between the oral and basal rows of tentacles. There are usually not more than 2 or 3 buds upon each polypite at the same time. The entoderm of this hydroid is white to rose-colored, the ectoderm silvery and translu- cent, and the perisarc horny-yellow to black. This hydroid ranges from the West Indies and Bermudas to the coast of Maine. Pentiaria gibbosa L. Agassiz, of the Florida coast and West Indies, is probably identical with P. tiarella, but the medusae of the southern form wither on the stem as do those of P. Jisticha. Indeed Agassiz's figure in 1862, shows the ultimate pedicels of his P. gibbosa, from Key West, Florida, ringed throughout as in the Mediterranean Pennaria disticha. Hargitt, 1900, has made a study of the life-history and development of P. tiarella. Early in the summer the hydroids are found growing on rock-weed, piles of docks, etc.; while late in the summer they take to eel-grass. The early summer brood is not so bright in color, and the medusae mature more slowly than in the late brood. The individual hydranths of the late brood are, however, smaller than those of the early summer brood. The medusae dis- charge their ova soon after liberation, and then die rapidly. The ova are 0.4 to 0.5 mm. in diameter and are heavily laden with yolk. They are creamy-white to orange in color. The cleavage is found by Hargitt to be subject to much individual variability, so that an extra- ordinarily irregular, loosely connected mass of cells is formed, resembling the condition described by Rittenhouse, 1907, in Turritopsis nutricula. No matter how irregularly shaped the embryo may be, it results finally in the formation of a spherical solid morula, and this soon changes into a pear-shaped, ciliated, planula larva. In 5 to 7 days after the beginning of development, the larvae settle down and then develop into small monogastric hydroids covered with ringed perisarc, and provided with whorls of tentacles as in the adult. Hargitt finds that the removal of small parts of the segmenting eggs does not alter the future history of development. The eggs may also be divided at the first or second cleavage and will still develop into normal larvae. Moreover, Hargitt finds that single eggs sometimes separate normally into two masses, each of which gives rise to a normal embryo. The irregularities in cleavage observed by Hargitt have been seen also by Miss Cora J. Beckwith. She finds that the segmentation is mytotic, not amitotic; the nuclear division constantly outnumbering the cytoplasmic so that a syncytium is formed. Hargitt, 1901, states that hydroid stocks of Pennaria which grow upon eel-grass in shallow water are more pinnatified in their branching, and more highly colored than are those which grow upon stones, etc., in deep water. He also finds that the medusae of the deep-water hydroids are less active than are those developed upon the hydroids which grow in shallow Flo. 2. — Southern variety of Pennaria tiarella. From life, by the author, Tortugas, Florida, May 27, 1908. Branch of hydroid and enlarged view of a polypite showing pedicels ringed only at their bases. ANTHOMEDfS.E — I'ENNAHI \. 27 water, and are often retained until they wither upon the stems after having cast out their genital products. I have found only the pale form of Pennarin on the Florida Reefs, and its medusae appear to cast out their genital products before being set free, as is described by Hargitt for the deep- water forms of Woods Hole, Massachusetts. In Florida, Pomona grows in tuft-like clusters upon gorgonians. This tropical form is called Pennana gtbbosa by L. Agassiz, but those seen by me can not be separated from the Pennaria of the coast of New England. Hargitt, 1899, carried out a series of grafting experiments upon Pennaria and other hydroids. He finds that pieces of hydroids of the same species may readily be grafted one upon the other, both in oral or aboral relations, there being little or no evidence of polarity in the regenerative process. Pieces of opposite sex but of the same species will readily unite in any manner, but pieces belonging to hydroids of different genera would not unite. Elaborate studies of this character were also carried out by Gast and Godewski, 1903, on P. Jisticha. In 1900 and 1901, Hargitt studied the variations of the medusx and hydroids of Pen- naria. The medusa sometimes displays ectodermal blister-like protrusions on its exumbrella, and is variable in other respects. According to H. Miiller, 1907 fZeit. fur wissen. Zool., Bd. 89), the eggs of Pennaria develop at the expense of the weaker egg-cells of the ovary, which they engulf as food to form the yolk-granules. Thacher, 1903, shows that in Pennaria, Campaniilana, and EiiJenJnurn, the hydranths, when they degenerate, are absorbed not by liquefaction of their protoplasm, or by the with- drawal of the polyps as a whole; but absorption takes place by the degenerating cells of both ectoderm and entoderm being turned into the digestive tract of the hydroid. Goldfarb, 1906, finds that light is absolutely essential for the normal growth, develop- ment, and regeneration of Pennaria. He finds, however, that this is true in a sense also for Eudendrium, but not to the same degree, for Eudendrnim ramositm colonies, kept in the dark until all the influence of their previous illumination has been lost, will not then regenerate new hydranths unless they be again exposed to light; but the surprisingly short exposure to light of only 5 seconds will suffice to restart the regenerative process. Pennaria rosea von Lendenfeld. Pennaria rosea, VON LENDENFELD, 1884, Proc. Linnean Soc. New South Wales, ser. I, vol. 9, p. 51)4, plate 24, figs. 40, 42. — BALE, 1888, Ibitl., ser. 2, vol. 3, p. 747 — 7*. australii, BALE, 1884, in Cat. Australian Hydroid Zoophytes, p. 45. Main axial stems 80 mm. long, with about 20 alternately arranged, pinnate side branches. 4 to 6 hydranths on each branch. Hydrorhiza and main stems intensely black and opaque; outer half of each stem light-yellow, proximal half intense black. Hvdranths rose-colored, with 9 to 14 oral, and 7 to 12 filiform, basal tentacles. Medusas are produced on the proximal hydranths. The medusa bell is slender, oval, 2 mm. high, I mm. wide. 4 large rudimentary tentacle-bulbs with a minute external ocellus upon each. Manubrium with sperm or ova fills the entire cavity of subumbrella. Ova discharged after medusa is set free. Color, intense rose. Coast of New South Wales, Australia. Mature in May. This species is distinguished from the European and American Pennaria by its tentacu- lar ocelli. Pennaria adamsia von Lendenfeld. Pennaria aaamsia, VON LENDENFF.LD, 1884, Proc. Linnean Soc. New South Wales, vnl. 9, p. 595, plate 25, figs. 45-48; plate 26, fig- 49- MeJusir. — The male medusae are 1.5 mm. long and only 0.7 mm. wide; while the female medusas are 1.5 mm. long and as broad as they are high. The male medusas have 4 radially situated marginal tentacles, about as long as the width of the bell. These tentacles have well-developed basal bulbs with minute ocelli, and the tentacles move about freely. The spermatozoa fill the space between the manubrium and the sides of the subumbrella, and are discharged within an hour after the medusa has been set free. The female medusas are broad, and the tentacles are mere rudiments without ocelli. The bell-cavity is filled with ova, which are soon discharged. 28 MEDUS.E OF THE WORLD. H ydroid. — The stems are 60 to 80 mm. long, zigzag, and with 15 to 20 alternate branches. The longest branches are nearest the base and are about 12 mm. long. There are about 8 hydranths, 1.7 mm. long, on each branch. These hydranths are slender, the proximal ones only about half as large as the distal primary one on each branch. There are 2 verticils of oral tentacles, each with 4 tentacles alternating in position with those of the other row. These oral tentacles are short and each ends in a nematocyst-knob. The uppermost row of 4 oral tentacles is in the 4 perradii, and the lower row in the 4 interradii. There are 24 long filiform tentacles in a single row at the broad base of the polypite. These are about as long as the polypite itself. The perisarc of the hydrorhiza and main stems is opaque and black, and the side branches are yellow. The hydranths are white. Coast of New South Wales, Australia. Medusae are produced in March. This species is distinguished by the minute ectodermal ocelli upon the tentacle-bulbs of the male medusae, and by the length of its tentacles. There are also but 2 verticils of oral tentacles. Pennaria pacifica Clarke. Pennaria pacifica, CLARKE, 1907, Mem. Museum Comp. Zool. Harvard Coll., vol. 35, No. l, p. 6, plate I, figs. 1-6. Hydrocaulus 20 to 35 mm. high. Internodes of the main stem without annulations at their distal ends, and with only I or 2 rings at their proximal ends. Branches alternate. Peduncles taper slightly to the base where there are 2 or 3 annulations. Hydranths with 12 to 14 filiments, and about 16 capitate tentacles somewhat irregularly arranged. Pinco Island, Gulf of Panama, tropical Pacific. Distinguished only by its few annulations at the internodes of the main stem. It is probably only a local variety of P. tiarella. Pennaria ? vitrea Agassiz & Mayer. Pennaria vitrea, AGASSIZ and MAYER, Bull. Mus. Comp. Zool. at Harvard Coll., vol. 32, p. 161, plate I, figs, l, 2. Bell is 3 mm. in height; walls thick and rigid. There are 4 rudimentary tentacle-bulbs. Velum not prominent. The 4 radial-canals are straight and narrow. The manubrium in the female specimen was retracted within the cavity of the bell, but it was flask-shaped in the male and projected for a short distance beyond the velar opening. These conditions, how- ever, may be merely different states of contraction and not constant differences; but as we observed only two individuals, one a male and the other a female, we can not be certain upon this point. The ova are large and pyriform, and are grouped in 4 interradially arranged clusters within the manubrium. The mouth-opening is simple, and there are no fimbriations or appendages. Prominent circular muscles were observed in the ectoderm ot the cavity of the bell in the female, but these were not seen in the case of the male. It is possible, however, that they become apparent only during certain states of contraction. In the female the ova and tentac- ular bulbs were flesh-colored, and the entoderm of the mouth was green. In the male the tentacular bulbs were green, the entoderm of the manubrium pink, and the lips green. Found among the Fiji Islands, off Kimbombo Island, November 25, and ofF Mbatiki Island, December 5, 1897. Not having seen the hydroid I am very doubtful concerning the generic identity of this medusa with Pennaria. Genus TRICHORHIZA Russell, 1906. Trichorhiza, RUSSELL, 1906, Proc. Zool. Soc. London, p. 99, plate 5. GENERIC CHARACTERS. The medusa is similar to that of Pennaria, but with one tentacle-bulb somewhat better developed than the 3 others. The hydranth is solitary, with a branched, filiform hydrorhiza. The perisarc forms a cup into the cavity of which the hydranth may be partially retracted. There are 2 verticils of tentacles, an oral and a basal; and the medusa-buds arise from the sides of the hydranth between these 2 verticils. The type-species is Trichorhiza brunnea Russell, from the Firth of Clyde, Scotland. ANTHOMEDUS.E — TRICHORHIZA, STEENSTRUPIA. 29 Trichorhiza brunnea Russell. Trichorhiza brunnta, RUSSKLL, 1906, Proc. Zool. Soc. London, p. 99, plate 5, figs. 1-2; Abstract, Pruc. Zool. Soc. London, No. 26, p. 6, Feb. 13, 1906. Mature medusa unknown. When newly set free from the hydroid the medusa is pyriform, with a thin-walled bell, well-developed velum, and 4 rudimentary tentacle-bulbs, one of which is larger than the others. The manubrium when extended is as long as the depth of the bell-cavity, and it is cylindrical, narrow, and provided with a simple, circular mouth- opening which is surrounded by nematocysts. There are 4 simple, straight radial-canals, but no gonads. The manubrium and tentacle-bulbs are yellow, the former being faint and the latter golden in color. This medusa is liberated by a solitary hydroid which was found on June 29, 1905, at a depth of 17 fathoms in Ethick Bay, Bute, Firth of Clyde, Scotland. The hydrorhiza of the Trichorhiza was entwined among and around the tentacles of Coryrnorpha nutans. The hydroid is 1 1 mm. in total length, the hydranth itself being only 1.5 mm. long. The hydrorhiza is long, filiform, and sparingly branched, with about 6 simple branches which arise from its lower (aboral) half. The coenosarc does not appear to extend over this branched lower half of the hydrorhiza. Above the upper end of the hydrorhiza the perisarc extends to form a cup-like hydrotheca, which bears 4 transverse grooves. Immedi- ately below this hydrotheca the peri- sarc displays several longitudinal lines. Hydranth conical, 1.5 mm. long and 0.8 mm. wide, with an oral circlet of 7 very short tentacles having knob- shaped ends. There is also a basal circlet of 12 filiform tentacles, which are ringed with nematocysts and are tapering, and fully as long as the hy- dranth itself. 8 or 10 medusa-buds arise at various levels from the sides of the polypite between the basal and oral circlets of tentacles. The perisarc of the hydrorhiza is straw-colored, and that ot the hydro- theca chocolate-colored. Body of hy- dranth pale reddish-brown, tentacles translucent white. This hydroid bears some resemblance to Blastothela of Verrill, 1878. Amer. Jour. Sci., ser. 3, vol. 1 6, p. 374. FK.. 3. — Trichorhiza brunnea, after Russell, Proc. Zool. Soc., London, 1900. Hydroid, and enlarged view of recently liberated medusa. Genus STEENSTRUPIA Forbes, 1846. Sleenslrufia, FOR BBS, 1846, Annals and Mag. Nat. Hist., vol. 1 8, p. 287.— LKI:CKART, 1856, Archiv. fiir Naturgesch., Bd.22, p. 29. Slrrnstrupia + Euf>h\!a, HAF.CKEL, 1879, Syst. der Mcdusen, pp. 29, 3 i .— BROWN t, 1895, Trans. Liverpool Biol. Association, vol. 9, pp. 247, 248. Eu/ihysa ±Sticnitrufia, AI.ASSIZ, L., 1862, Com. Nat. Hist. I'. S., vol. 4, pp. 542, \^\. HAM KM , 1X64, Jena. Zeitsrli. fur Naturw., Bd. I, pp. 338, 339. -FoRin.s, \X^, Hntisll N,iked-eved Medusa-, pp. 71, 72. Euph\ia, A(.ASSIZ, A., 1865, North Amer. Acal., p. 1*0. UK. MOW. i'jc>4, Bull. Mus. Comp. Zool. at Harvard Coll., vol. VI. p. 251. — VANHOKFFN, 1891, Zool. An/eiger, lid. 14, p. 443. Ku/>h\sora, MAAS, 1905, Hydromeduscn der Siboga Kipediiion, p. 6. Heterosirf>hanus + Stcenslrupia+ Eaf>h\sa, HARTLALB, 1907, Nordischcs Plankton, Nr. 12, pp. 74, 76, 80. 30 MEDUS.E OF THE WORLD. The type-species ot this genus is Steenftrupia rubra Forbes, 1846, from the Atlantic coasts of Europe. GENERIC CHARACTERS. Codonids with radially symmetrical bell, and with 4 radially situated tentacles, I of which is well developed while the 3 others are short or rudimentary. This genus is separated from Hybocodon by its radially symmetrical bell. In Hybocodon i radial-canal is long, I short, and 2 of medium length; but in Steenstrupia the 4 radial -canals are all of the same length. Synopsis of the Characters of MeJuste of the Genus Steenstrupia. S. rubra Forbes= S. aurata= Euphy- S. tetrabrachia=E. S. bigelowi Maas. S. australis von S.flaveola Forbes sa aurata Forbes, tetrabrachiaH.B. Lendenfeld. = S. galanthus = E. aurata+E. Bigelow. Haeckel =(?)£. mediterranea gracilis Brooks= Haeckel = (?) E. ( ?) S. cranoides virgulata A. Haeckel=S. 1m- Agassiz. eata Leuckart. Shape and size Bell has well-devel- Dome-like apex. Pyriform. 4 high, Pyriform. 10 high, Half-egg-shaped, of bell in mm. oped apical pro- Cylindrical sides. 2.5 wide. 5 wide. 2.5 high, 1.7 jection. 5 high, 6 high, 4.5 wide. wide. 3 wide. Bell-walls and apex thick. Condition of ten- 3 long, narrow ten- 3 small, similar, 3 short tentacles, 3 short tentacles 3 tentacle-bulbs, tacles. Length tacle-bulbs with- rudimentary ten- each= r long, i about 2 r long and i long tenta- in terms of bell- out tentacles, all tacle-bulbs, i large tentacle and not ringed. cle, ringed with radius (r). similar, i long long tentacle. about 7 T long. One longtentacle nematocysts. tentacle ringed Length = 2 r+ . All tentacles 4 T long, with Long tentacle with nematocysts. No ocelli. No sparsely ringed. many prominent about 8 r long. Length = 7 r. definite rings of partial rings of nematocysts on nematocysts. tentacles. Axial-canal above Axial canal always No axial-canal. No axial-canal. Present. Small, No axial-canal. stomach. present. slender. Length of manu- 1 .5 r. Stomach 1.25 r. No ped- 2. 5 r long. Mounted 1.5 r long. Mouth 1.5 T long. Cylin- brium in terms mounted on short uncle. on very short ped- not quite reach- drical. of bell-radius peduncle. uncle ? Mouth ing level of velar (<•). extends slightly opening. beyond velar opening. Gonads. Single gonad en- Single gonad en- Eggs developed in 4 wide interradial, Gonad encircles circles stomach, circles stomach. 8 adradial, longi- ectodermal swell- manubrium. leaving mouth and tudinal rows, in ings on sides of peduncle free. ectoderm on sides mid-region of man- of stomach. ubrium. Separated by 4 narrow, per- radial spaces. Color. Tentacle-bulbs and Variable. Tenta- Gonads brownish- Entoderm of man- Mouth deep violet. stomach light- cle-bulbs may be yellow. Mouth ubrium, canals, 4 brown patches pink to reddish- yellow, orange, pink. Tentacle- and tentacles dull on gonad. Tenta- brown. Bell apex red, or colorless. bulbs and rings yellow . cle-bulbs and long sometimes faint Manubrium red- pink. tentacle brown pink . dish to yellow or with violet spots. faint purple. Where found. Atlantic coasts of Mediterranean and Suvadiva Atoll, Malay Archipelago. Harbor of Sydney, Norway, Ger- Atlantic coasts of Maldive Islands, New South many, England, Europe. Indian Ocean in Wales, Australia. Scotland, and Ire- January. land. (Mediter- ranean?) (South- ern United States, Atlantic coast?) Hydroid. Corymorpha nu- Corymorpha nana, Unknown. This medusa is pro- Unknown. tans, Sars, 1835; Alder, 1857. bably identical Hincks, 1868; with S. tetrabra- Allman, 1871. chia. Hydroid unknown. ANTHOMEDUS.E — STEENSTRUPIA. 31 The hydroid generation is Corymorpha Sars, i$3$ = Halatractus of Allman, 1871. Haeckel, 1879, restricts Steenstrupia to describe medusae having characters as above, but with an apical projection upon the bell, and with an axial canal extending upward into this projection from the stomach. Euphysa he would restrict to include forms which lack an apical projection and an axial canal. As Vanhoffen, 1891, rightly states, an apical projection is always lacking in young medusae and is highly variable in its development even in mature individuals of the same species. The same is true of an axial canal. Moreover, among species discovered since Haeckel wrote his "System der Medusen," Euphysa tetrtibrachin, Bigelow, 1904 (Bull. Mus. Comp. Zool. at Harvard Coll., vol. 39, p. 251, plate I, fig. i), has a well-developed apical projection, and no axial canal, and would therefore have no place in Haeckel's system. Maas, 1905, would institute a genus Euphysora to describe Codonidae having I large, and 3 well-developed but still considerably smaller tentacles. Here again, however, we meet with a condition of degree only. When, for example, are the 3 small tentacles large enough to be Euphysara or small enough to be Steenstrupia ? In order to avoid confusion, it appears best to combine all of these forms under one generic name. Vanhb'ffen, 1891, suggests Euphysa as the proper generic name to include all of these forms, but Steenstrupia takes precedence over Euphysa, for it was used by Forbes in 1846, while Euphysa was first used by him in 1848. Bigelow finds that the eggs of S. tetrabrachia are arranged in 8 adradial longitudinal lines in the ectoderm of the stomach, and Maas states that in S. bigelou'i the gonads are interradial and separated by very narrow linear interspaces in the 4 principal radii. These conditions are interesting, for they foreshadow those characteristic of the Oceanidae where the gonads are interradial or adradial, and are often quite widely separated in the principal radii. Hartlaub, 1907, defines Heterostephanus (Allman, 1871) as a Steenstruf>ia-\\ke medusa-bud, not known to be set free from its Coryrnorpha-\\\ie hydroid. Medusa with a single tentacle, ringed at its base, and terminating distally in a knob. The only known species is H . annuli- cornis, Allman, l^l=Hybocodon annulicornis Haeckel. This was first described by M. Sars, 1859; as Corymorpha ? annulicornis. Steenstrupia rubra Forbes. Plate I, fig. 7. Corymorpha nutans (hvdroid), SARS, M., 1835, Beskriv. og Jagtt., p. 6, plate i, fig. 3; SARS, O., 1877, Fauna Littor. Norveg., tome 3, p. 2, taf. 2, figs. 25-28. Corymorpha nutans (hvdroid), BEDOT, 1905, Revue Suisse de Zool., tome 13, p. 63 (literature to 1850). Corymorpha nutans (hydroid and medusa), HARTLATB, 1907, Nordisches Plankton, Nr. 12, p. 76, figs. 72-75 (complete li authors, localities, and best modern description of hydroid and medusa). Corymorpha nutans, HINCKS, 1868, Hist. British Hvdroid Zoophytes, p. 127, plate 22. — AI.LMAN, 1871, Monog. Tubularian Hydroids, p. 388, plate 19. Corymorpha nuians = S. galanthus (Haeckel)=.S. faveola, Forbes = S. rubra, Forbes, BROWNE, 1896, Proc. Zool. Soc. London, pp. 463, 464, plate 16, fig. i (review of literature). Steenstrupia galanthus, BEDOT, 1905, Revue Suisse de Zool., tome 13, p. 148 (literature to 1850). — HAECKEL, 1879, Syst. ilrr Medusen, p. 31. Hybocodon ntttans, Ibid., p. 34. — MULLER, 1908, Zeit. fur wissen. Zool., Bd. 89, p. 52, taf. 5, figs. 20-24 (origin and structure of the eggs). Steenstrupia rubra, HARTLAUB, 1904, Wissen. Meeresuntersuch. Kommiss. Meerc Kiel, Abth. Helgoland, Neue Folgc, Bd. 5, p. 105, fig. 3. Steenstrupia rubra (Forbes), BROWNE, 1895, Trans. Liverpool Biol. Soc., vol. 9, p. 247. Steenstrupia rubra (medusa)+S. faveola, FORBES, 1848, British Naked-eyed Medusa, pp. 73, 74, plate 13, figs, i, 2. Steenstrupia cranoides, HAECKEL, 1879, Syst. dcr Medusen, p. 30, taf. 2, figs. 10-14. Steenstrupia gracilts, BROOKS, 1882, Studies Johns Hopkins Vniv. Biul. Laboratory, vol. 2, p. 144. — MAYER, 1900, Bull. Mus. Comp. Zoo!, at Harvard Coll., vol. 37, p. 29, plate 16, figs. 36, 37. Steenstrupia lintata, LEUCKART, 1856, Archiv. fur Naturgesch., Bd. 22, p. 29, taf. 2, fig. 6. — SPACNOLINI, 1876, Catali-i:" \ Mediterraneo, p. 17, taf. I, figs. 1-4. — HAECKEL, 1879, Syst. der Medusen, p. 30. — DU PLESSIS, 1888, Recueil /.<«.!. s,n re, tome 4, p. 543. This medusa is found on the coasts of Europe from Norway southward to the Mediter- ranean. S. cranoides Haeckel = .V. lineata Leuckart, from the Mediterranean, appears to be identical with S. rubra. S. gracilis Brooks, of the Atlantic coast of the United States south of Virginia, is probably identical with S. rubra of Europe, but the hydroid of the American form remains unknown. I believe that 5. Un<-ntn, S. rrtinoiJfs, and .V. i>r/ii-ilis are identical, and that they are probably identical with .V. ruhrn Forbes. For description of i'. rubra of Europe, see synoptic table of species of Steenstrupia. 3 32 MEDUSAE OF THE WORLD. In the American form the development of nematocyst-rings upon the long tentacle is subject to great variability. The Mediterranean S. cranoides Haeckel lacks such rings, whereas they appear to be better developed in northern Atlantic specimens from the coasts of Europe. The same difference appears to be exhibited by our American specimens, those from Tortugas, Florida, being unnnged or only slightly ringed, while those from North Car- olina are often profusely ringed. The apex of the bell often bristles with nematocysts, but in some medusae it may be smooth. Browne, 1896 (pi. 16, fig. i), gives a figure of S. rubra derived from specimens found by him at Valencia Island, off the Irish coast. He shows a narrow conical peduncle above the stomach, the peduncle being about one-fifth as long as the gastric portion of the manubrium. No such peduncle has been observed in the American S. " gracilis," when the bell is expanded, although when it is somewhat contracted the appearance of a well-developed peduncle is often produced. On the other hand, when the stomach is widely distended with food and the bell expanded no peduncle may be seen. Haeckel's series of figures (taf. 2, figs. 10-12) will 3> FIG. 4. — Corymorpha nulans, after Hartlaub, in Nordisches Plankton. (Young hydroids and mature medusa.) serve to illustrate the formation of a peduncle-like body of gelatinous substance above the stomach through contraction of the bell. I have frequently seen the same phenomenon in our American S. " gracilis" = S. cranoides Haeckel. I have also observed this peduncle in living medusae of S. rubra taken off the coast of Cornwall, England. Hartlaub, 1907, gives a list of the bibliography and of localities for this species, and his description of the medusa and the young hydroid are the best yet produced (see fig. 4). The egg is amoeboid as in Amalth&a. The young hydroid has a single circlet of 4 short, knobbed, oral tentacles, and another circlet of 5 to 8 simple, flexible, filiform basal tentacles. H. Miiller, 1908, finds that the full-grown eggs are very few in number, having developed at the expense of other weaker egg-cells in the ovary, which they devour. The exoplasma is quite wide and is separated from the germinal vesicle. The ooplasma is a network of delicate fibers of wide mesh, and the exoplasma and endoplasma are distinct, one from another. The egg contains numerous pseudo-cells in advanced stages of degeneration and also yolk-granules. ANTHOMEDUS.E STEENSTRUPIA. 33 The following description of the medusa is derived from a study of specimens found by the author off the coast of the United States: The bell is 5 mm. high and surmounted by a slender conical projection about 2 mm. long. There are 4 tentacles. One of these is about 10 mm. long, and is ringed at irregular intervals by prominent swellings, between which there are small rings at fairly regular inter- FIG. 5. — Corymorfha nuians, hydroid and medusa, after Allman, in Ray Society, 1871-72. A' Detail showing manner in which medusa1 bud off from hydranlh. 34 MEDUSAE OF THE WORLD. vals. The tentacle which is diametrically opposite to the long tentacle is tapering, and about 0.25 mm. long; while the 2 other tentacles are mere bulbs. The velum is well developed. There are 4 narrow radial-canals, and a slender ring-canal. A long, slender, sinuous canal extends from the aboral apex of the stomach upward into the apical projection of the bell. In mature medusae the manubrium extends a short distance beyond the velar opening. Ordinarily the mouth is a simple, round opening at the tapering extremity of the manubrium, but when widely open, as in our figure, it shows 4 thick but not prominent lips. The genital products are found in the manubrium, and in the female the eggs project from the surface of the ectoderm. Entoderm of manubrium intense yellow-green and rose-color. Apical canal intense yellow, often flecked with rose-color. The entoderm of the tentacle-bases is rose- color and yellow, while the entoderm of the large annular swellings is rose-color. When young the apical projection is not very high, the tentacles short, and without nematocyst- nngs, and the manubrium short and tapering; not extending beyond the velar opening as in the mature medusa. 6. FIGS. 6 and 7. — Sieenslrufia rubra. 6. — From life, by the author. Off Mousehole, Cornwall, England, October 23, 1907. 7. — A. After Leuckart ("S. lineata"), 1856, Archiv. fur Naturgesch., Bd. 22. B. After Spagnolini ("S. lineata"*), 1876, Catalogo Acalefi Mediterraneo. Found at Oregon Inlet, Pamlico Sound, North Carolina, in November, and at Beau- fort, North Carolina, and Tortugas, Florida, in summer. It is apparently identical with S. cranoides and S. lineata of the Mediterranean. Definite rings of nematocysts are not found upon the tentacles of the young medusa, and are very variable in their development in mature specimens, some being profusely ringed and some entirely unringed. Haeckel describes only unringed individuals from the Medi- terranean, his specimens being similar to those found by me at Tortugas, Florida. I am inclined to believe that this Mediterranean and tropical American medusa will prove to be identical with, or only a variety of, S. rubra of the Atlantic coasts of western Europe. Certainly no differences, other than those well within the limits of common vari- ability, can be detected between the medusae of S. rubra and S. lineata = S. cranoides; but a ANTHOMEDUS.E — STEENSTRUPIA. 35 careful comparative study of the hydroids of these forms must be made before we may safely assert either that they are identical or separate species. The hydroid of S. rubra is Corymorpha nutans of Sars, and is common on sandy bottoms, off the northern coasts of Europe, at moderate depths. The stems of the hydroid are solitary, and are about 50 to 75 mm. high, and about 4 mm. wide at the widest part. The whole stem is corrugated by numerous narrow longitudinal bands. The widest part of the stem is usually at a short distance above the lower end. This lower end is bent sharply at right angles to the main part of the stem and bears long, hair-like filaments which serve to anchor the hydroid. There are also blunt, papilla-like processes which arise from the sides of the stem above the bent portion. The polypite is large and flask-shaped, and has a basal zone of 30 or more long, tapering tentacles, about as long as the polypite itself. In addi- tion to these tentacles there are 6 to 7 closely crowded verticils of oral tentacles, which are much shorter and thinner than the proximal. 15 to 20 branched peduncles arise from the sides of the polypite close to the bases of the proximal circlet of tentacles, and bear the medusa-buds. The hydranth is light-red, the stem being paler than the polypite. On the English coast the medusa-buds are set free during the summer. Allman gives a good description of the hydroid. Steenstrupia aurata. Euphysa aurata, (medusa) FORBES, 1848, British Naked-eyed Meduss, p. 71, plate 13, fig. 3. Euphysa aurata (medusa)+E. mcditcrranea, HAECKEL, 1879, Syst. der Medusen, p. 32, taf. 2, figs. 8, 9. Euphysa medilrrranca, DU PLESSIS, 1888, Recueil Zool. Suisse, tome 4, p. 543. Euphvsa aurata (Forbes), BROWNE, 1895, Trans. Liverpool Biol. Soc., vol. 9, p. 248; 1896, Proc. Zool. Soc. London, p. 474. Euphvsa aurata, BROWNE, 1905, Proc. Roy. Soc. Edinburgh, vol. 25, p. 749. — BEDOT, 1905, Revue Suisse de Zool., tome 13, p. 134. Corymorpha nana, (hydroid) ALDER, 1857, Cat. Zooph. Northumberland and Durham, p. ill, plate 7, figs. 7, 8. — HINCKS, 1868, Hist. British Hydroid Zooph., p. 130, plate 22, fig. 3. Corymorpha nana, HARTLAUB, 1907, Nordisches Plankton, Nr. 12, p. 81, figs. 76-78 (list of authors and localities). (?) Euphysa virgulata, AGASSIZ, A., 1865, North Amer. Acal., p. 189, figs. 316-319. This medusa is found off" the Atlantic coasts of western Europe and in the Mediter- ranean. Steenstrupia virgulata of Massachusetts Bay is probably identical with S. aurata. For description of the European form, see synoptic table of characters of the species of Steen- strupia. The European S. aurata appears to be smaller than the American S. virgulata. Steenstrupia virgulata = (?) S. aurata Forbes. Plate i, fig. 6. (?) Steenstrupia aurata, FORBES, 1848, British Naked-eyed Medusae, p. 71, plate 13, fig. 3. Euphysa virgulata, AGASSIZ, A., 1865, North Amer. Acal., p. 189, figs. 316-319. — HAECKEL, 1879, Syst. der Medusen, p. 33. — NUTTING, 1901, Bull. U.S. Fish Com m., vol. 19^.370. — HARGITT, 1904, Bull. U. S. Bureau of Fisheries, vol. 24, p. 33. Corymorpha virgu/aia, HARTLAUB, 1907, Nordisches Plankton, Nr. 12, p. 84, fig. 79. Adult medusa. — The bell is pyriform, with a broad, dome-shaped apex. It is 5 to 12 mm. in height, and 4.5 to 9 mm. in diameter. Surface of exumbrella smooth and without rows of nematocysts. There are 4 tentacles, one at the base of each radial-canal; 3 of these are mere rudimentary bulbs, but the fourth is large and conical. Its surface is thickly covered with nematocyst-cells of large size. There are 4 simple, straight radial-canals, and a slender, circular vessel. The velum is wide, with an indented, free edge. The manuhrium is cylin- drical without a peduncle, and extends about half the distance from the inner apex of the bell-cavity to the level of the velar opening. No apical, axial canal. The mouth is a simple, round opening without prominent lips. The genital products are contained within the ectoderm of the manubrium. Manubrium light-yellow. The entoderm of the radial- canals near the bases of the tentacles is intense pink, and the ectoderm of the tentacles is milky-white. This species was found by Dr. Alexander Agassiz, in Massachusetts Bay, at Nahant, and is recorded from Woods Hole, Massachusetts, by Nutting and Har^itt. The figure here shown is reproduced by his kind permission from Dr. Alexander Agassiz's drawing of the medusa. There is no difference between this medusa and S. aurata of Europe except that the American form appears to be larger; but the hydroid of the American medusa is unknown, and until this is discovered it will be impossible to determine the identity of the American form. 36 MEDUSAE OF THE WORLD. Steenstrupia tetrabrachia. Euphysa telrabrachia, BIGELOW, H. B., 1904, Bull. Mus. Comp. Zool. at Harvard College, vol. 39, p. 251, plate I, fig. I. (?) Euphysora bigelowi, MAAS, 1905, Craspedoten Medusen der Siboga Expedition, Monog. 10, p. 7, taf. I, figs. 1-3. Bell 4mm. high, 2. 5 mm. wide. Pyriform,with solid apical projection. One long sparsely- ringed tentacle about 4 times as long as the bell is high. 3 other, smaller tentacles, each about one-third as long as the bell-height. These bear each about 3 rings of nematocysts, while the long tentacle bears about 6 such rings. Velum well developed. Manubrium large, spindle- shaped, with mouth projecting beyond the velar opening. Gonads on sides of stomach. Eggs arranged in 8 fairly distinct rows. Bell colorless. Gonads brownish-yellow. Manubrium pinkish. Tentacle-bulbs and rings on tentacles rose-pink. Suvadiva Atoll, Maldive Islands, Indian Ocean; in January. This medusa is probably redescribed by Maas as E. bigelowi. Steenstrupia bigelowi. Euphysora bigelowi, MAAS, 1905, Craspedoten Medusen der Siboga Expedition, Monog. 10, p. 7, taf. i, figs. 1-3; 1906, Revue Suisse de Zool., tome 14, p. 84, pi. 2, figs, i, 2. — MULLER, 1908, Zeit. fur wissen. Zool., Bd. 89, p. 59. (?)Euphysora tetrabrachia, BIGELOW, 1904, Bull. Mus. Comp. Zool. at Harvard College, vol. 39, p. 251, plate i, fig. I. Fir,. 8. — Steenstrupia tetrabrachia, after Bigelow, in Bull. Museum Comp. Zool. at Harvard College. FIG. 9. — Steenstrupia bigelowi, after Maas, in Hydromedusen Siboga Expedition. Bell 13 mm. high; more than twice as high as it is wide, and with a well-developed apical projection. Bell-cavity 10 mm. deep. Apical projection 3 mm. high. Side walls thin. 4 tentacles at the bases of the 4 radial-canals. One of these tentacles is longer than the bell- height and bears about 30 swollen nematocyst-warts. The 3 other tentacles are each one- third to half as high as the bell and are tapering, without nematocyst-warts, but covered with diffuse nettling cells. Manubrium spindle-shaped, not extending beyond the velar opening. ANTHOMEDUS.E — STEENSTIU'I'IA, HYBOCODON. 37 In most specimens there is a blindly-ending axial canal extending into the gelatinous substance of the apical projection, but this is not constantly present. The gonads are developed upon the sides of the stomach, leaving only the basal and mouth ends of the manubrium free. A cross-section shows that they are separated by 4 minute, perradial, longitudinal lines. There are therefore 4 interradial gonads. There are no medusa-buds produced by the medusa. The entoderm of the manubrium, radial-canals, and tentacle-bulbs is filled with yellow pigment granules. The nematocyst clusters on all 4 tentacles are red. Found quite commonly in the Malay Archipelago, at Sulu, Ternate, Damar, Manifa, Saleyer, and Amboina. This form differs from the closely allied S. letrabrachia Bigelow, from the Maldive Islands, in that in the Maldive species there are a few rings of nematocysts upon the ten- tacles, whereas in S. bigelou'i there are only warts, not inclosed rings. Also there appears to be no axial canal in S. tetrabrachia, whereas this is usually seen in 5. bigelowt. The size constitutes a disparity in the two medusae 4 mm. high in S. tetrabrachia and about 13 mm. in S. bi^elowi. Future studies will probably show that these distinctions are not of specific value, but merely changes due to growth and variation, and that the two medusae are identical and should be called S. tetrabrachia. "Euphysa" tentaculata, Linko, 1905 (Zool. Anzeiger, Bd. 28, p. 214), from Barents Sea has also 3 well-developed tentacles, and is 5 mm. high, with orange-colored manubrium and oval bell. It may be Hybocodon pcndula. Steenstrupia australis. Euphysa ausiralis, VON LENDENFELD, 1884, Proc. Linnean Soc. New South Wales, vol. 9, p. 586, plate 21, fig. 33. Bell is 2.5 mm. high, 1.7 mm. wide. Half-egg-shaped and symmetrical. No lines of nematocysts over the exumbrella. One very long retractile tentacle, 2 to 3 times as long as the bell-height. This tentacle has a large basal bulb, and is covered with rings of nemato- cysts. The other 3 tentacles are mere basal bulbs terminating in a knob-shaped cluster of nematocysts. Velum well developed. 4 straight radial-canals. Manubrium arises from the center of the umbrella cavity, and is cylindrical and about half as long as the bell-height. The gonad encircles the manubrium. Mouth deep violet. 4 brown patches upon the gonad, and a few brown spots on manubrium near its base. Tentacle-bulbs and the large tentacle brown with violet spots. Port Jackson, New South Wales, in May and June. Rare. Hydroid unknown. Genus HYBOCODON L. Agassir, 1862. Htbocodon, AGASSIZ, L., i86z, Cont. Nat. Hist. U. S., vol. 4, p. 243.— AGASSIZ, A., 1 865, North Amcr. Acal., p. 193.— VANHOFFEN, 1891, Zool. Anzeiger, Bd. 14, p. 443. — BROWNE, 1896, Proc. Zool. Soc. London, p. 466. — HARTLAI B, 1905, Zoolog. Jahr- buchern, Suppl. 6, p. 544; 1907, Nordisches Plankton, Nr. 12, p. 96. HybocoJon + ArnphicoJon, HAECKF.L, 1879, Syst. der Medusen, pp. 33, 35. Amphirodon, BROWNE, 1901, Annals and Mag. Nat. Hist., ser. 7, vol. 9, p. 275. Diplura, ALLMAN, 1871, Monog. Tubularian Hydroids, p. 326. Corymorpha, AGASSIZ, A., 1865, /feiW., p. 192. This genus was established in 1862 by L. Agassiz for Hybocodon prohfer, a medusa which arises by budding from a Corymor^/ja-like hydroid on the New England coast. Accord- ing to Browne, 1896, this medusa is also found off the northern coast of Europe. It is prob- able that the same medusa was described by Steenstrup, 1842, from Iceland, as Corymorpha fritillaria, but the hydroid from which Steenstrup supposed this medusa to be derived is certainly not HvbocoJon, but may be an Arnalthira or Diplura. Steenstrup does not figure a basal circlet of tentacles upon the polypites, which have only an oral circlet, and below this a circlet of medusiform gonophores, each with a 4-sided bell, and 4 equally developed rudimentary tentacles. It is probable that the hydroids of Hybocodon differ more among themselves than do the medusae, and no final classification of the medusae can be attempted until all of the hydroids have been discovered. GENERIC CHARACTERS. Codonidae with asymmetrical bell. One of the 4 radial-canals is long. I short, and 2 of medium length. There are I or more long tentacles at the foot of the long radial-canal; and 3 small or rudimentary tentacles, I at the foot of each of the 3 other radial-canals. The hydroid is HybocoJon. 38 MEDUS.E OF THE WORLD. Haeckel, 1874, instituted the genus Amphicodon to include medusae with 3 rudimentary tentacles, and a cluster of 2 or more long tentacles at the foot of the longest radial-canal. Vanhoffen, 1891, Browne, 1896, and Hargitt, 1901, have pointed out, however, that the young medusae commonly have but I long tentacle, and that others appear, and develop from the side of the basal bulbs of this original tentacle; thus the genus "Amphicodon" is only a mature Hybocodon. These secondary tentacles may appear before or after the medusa- buds begin to develop upon the tentacle-bulbs. According to Hargitt, 1902, 1904, Perkins, 1904, and Linko, 1905, the sexual products of the manubrium become mature while medusa-buds are still being produced upon the tentacle-bulbs. Synopsis of the Species of Hybocodon.* H. prolifer L. Agassiz. H. pendula Haeckel = Corymorpha pendula L. Agassiz. H. forbesii Mayer. H. unicus Browne. Shape and size of bell Dome-shaped. 2.5 high, Quite similar to H. pro- Ellipsoidal, asymmetri- Bell-shaped. 3 high, in mm. 2.2 wide, i radial- lifer. 5 high, 3.5 cal. 2.5 high, 2.1 2 wide. canal long, 2 inter- wide. wide. mediate length, and i short. Long and short are 180° apart. Number of longitudi- 2 extend upward from As in H. prolifer. None. ? nal lines of nemato- base of well-developed cysts on exumbrella tentacle, and I from base of each of 3 rudi- mentary tentacle-bulbs. Condition of well-de- i to 3 well-developed ten- Only i well-developed Only i well-developed Only i well-developed veloped tentacle, or tacles at base of longest tentacle. No medusa- tentacle. No medusa- tentacle "between 2 cluster of tentacles, radial-canal. Medusa- buds. buds. rudimentary basal at base of longest buds are produced at bulbs." No medusa- radial-canal. bases of these tentacles. buds. Often only i well- developed tentacle pro- duced. Condition of 3 rudi- Mere basal bulbs. i mere basal bulb. 2 i short conical tentacle. 3 mere basal bulbs. mentary tentacles. small tentacles. Small 2 mere basal bulbs. tentacles 90° and Short conical tentacle basal bulb 180° from 1 80° and basal bulbs large tentacle. 90° from long tentacle. Gonads. Developed over ectoderm On ectodermal sides of On manubrium. No ? of manubrium. Actinula manubnuni. No ac- actinulx attached to larvs develop upon sur- tmulie seen attached gonad. face of gonad in ecto- to gonad. derm of manubrium. Color. Entoderm of tentacle- Pink granules in tenta- Entoderm of tentacles ? bulbs, radial-canals, cle-bulbs. Entoderm and manubrium yel- and stomach orange to of manubrium pink low, flecked with red. deep blood-red. and lilac. Where found. North Atlantic coasts of Coast of New England, Bahama Islands, and Stanley Harbor, Falk- Europe, Iceland, and United States. Florida coast. Com- land Islands. America. mon in spring months, at surface. Hydroid . Hydroid described by L. Hydroid is Hybocodon Unknown. Hydroid may be H. Agassiz, 1862, as H. pendula= Corymorpha chilensis Hartlaub, prolifer. pendula L. Agassiz. 1905. *For description of H. chilensis Hartlaub, H. chrislinf Hartlaub, H. pu/cher Hartlaub, and H. (?) januarii, see text. Hybocodon prolifer L. Agassiz. Plate 2, fig. i; plate 3, fig. 3. (?) Corymorpha fritillaria, STEF.NSTRUP, 1842, Generations-wecksel., p. 20, taf. I, figs. 41-46 (the medusa only may be identical with //. prolifer; the hydroid appears to be an Amaltheea or Diplura). ( ? ) Stcenstrupia globosa, SARS, 1859, Christiania Vidensk. Selsk. Forhandl., p. 101. — KOREN and DAWELSSEN, 1877, in Sars's Fauna Littoralis Novegiie, tome 3, p. 20, taf. i, figs. 1-6. (?) Corymorpha annulicornis (young medusa), KOREN and DANIELSSEN, 1877, Ibid., p. 8, taf. i, figs. 7-13. PLATE 2. Fig. I. Hybocodon prolifer. Woods Hole, Massachusetts, March 4, 1907. This drawing shows one of the normal aspects of the medusa, with the bell somewhat contracted. When the bell is extended the mouth comes to the level of the velar opening. Fig. 2. Hybocodon pendula. Newport, Rhode Island, April 23, 1897. Fig. 3. Hybocodon forbesii. Tortugas, Florida, June 26, 1906. Fig. 4. Dicodoniurn jeffersoni. Tortugas, Florida. Fig. 5. Dicodoniurn floriJana. Tortugas, Florida, June 17, 1897. Drawn from life, by the author. PLATE 2 ANTHOMEDUSJE — HYBOCODON. 39 Hybocodon prolijer (hydroid and medusa), AOASSIZ, L., 1861, Cent. Nat. Hist. U. S., vol. 4, pp. 143, 343, plate 133, figs. 10, 11; plate 25, 19 figs. Hybocodon proltffr, AGASSIZ, A., 1865, North Amer. Acal., p. 193, figs. 325-328. — ALLMAN, 1871, Monog. Tubul. Hydroids, p. 422. — VERRILL, 1873, Invert. Animals, Vineyard Sound, p. 736, plate 38, fig. 282. — BOHM, 1878, Jena. Xritschr. fiir Naturw., Bd. 12, p. 195, taf . 7j figs. 7-9. — NUTTING, 1901, Bull. U.S. Fish Commission, vol. 19, p. 341, fig. 76. — HARGITT, 1904, Bulletin Bureau of Fisheries U. S., vol. 24, p. 33, plate 2, fig. 2; 1901, American Naturalist, vol. 35, p. 580, fig. 39; Ibid., 1902, vol. 36, p. 552; 1901, Biol. Bulletin Woods Hole, vol. 2, p. 222. — PERKINS, 1904, American Naturalist 38, p. 516 (simultaneous sexual and asexual reproduction). (?) Hybocodon prolijer, BROWNE, 1896, Proc. Zool. Soc. London, p. 466. Hybocodon prolifer + H.annulicornis + ? Amphicodon fritillaria+ ? A. giobosus + A.amphipleurus, HAKCKEL, 1879, Syst. JerMcdu- sen, pp. 33, 35, 36, 37, taf. I, figs. 7-9. (?) Amphicodon fntillaria, BROWNE, 1895, Trans. Liverpool Biol. Soc., vol. 9. (?) Amphicodon grtn°idum, LINKO, 1905, Zool. Anzeiger, Bd. 28, p. 215 (simultaneous sexual and asexual reproduction). (?) Hybocodon prolifer, BROWNE, 1905, Proc. Roy. Soc. Edinburgh, vol. 25, p. 752. Non Hybocodon prolijer, BONNEVIE, 1899, The Norwegian North Atlantic Expedition, 1876-1878, vol. 26, Hvdroida, p. 28, plate i, fig. 6. Hybocodon prolijer, HARTLAUB, 1907, Nordisches Plankton, Mr. 12, p. 98, figs. 94-97. — MULLER, H., 1908, Zeit. fur wissen. Zool., Bd. 89, pp. 62, 73 (origin and structure of the eggs). ( ?) Hybocodon gravidum + H. islandicus + H . amphipleurus, HARTLAVB, 1907, Nordisches Plankton, Nr. 12, pp. 104, 106, figs. 99, 100. The following description is derived from studies made of medusae from the southern coast of New England, United States: Adult medusa. — Bell about 2.5 mm. high and 2.2 mm. wide. It is asymmetrical, the side bearing long tentacles being longer than the other sides; or as Browne aptly describes it, the margin is not at right angles to the longitudinal axis of the bell, but slopes toward the side bearing the cluster of long tentacles. The 4 radial-canals are of lengths corresponding to the sides of the bell. The canal leading to the cluster of long tentacles is the longest; while the canal diametrically opposite to this is the shortest, the 2 other canals being of inter- mediate length. There are 3 small, rudimentary tentacle-bulbs, I at the foot of the shortest canal, and I at the foot of each of the intermediate canals. The cluster of tentacles at the foot of the long radial-canal has wide, hollow, tapering basal bulbs. The mam shaft of each tentacle is, however, slender, cylindrical, and contractile, and is annulated at regular intervals by well-developed clusters of nematocysts. Young medusae commonly have but a single long tentacle, but as growth proceeds they sometimes develop another and finally a third; and all 3 grow to be of equal length, and form a conspicuous cluster. A number of medusa-buds in various stages of development arise from the sides of the hollow base of the one or more long tentacles, near the bell-margin. These medusa-buds themselves develop a single long asymmetrical tentacle even before the bud is mature. When ready to be set free they resemble the parent medusa in that they are sometimes observed to be developing a third generation of medusae upon their tentacle-bulbs. 5 longitudinal lines of nematocyst-cells extend from the bases of the tentacles to near the apex of the bell. 3 of these rows arise from the bases of the 3 rudimentary tentacles, and extend up over the surface of the exumbrella immedi- ately over the radial-canals. In addition to these there are 2 rows which start from the base of the well-developed tentacles, and extend upward over the exumbrella surface on both sides of the long radial-canal. The velum is well developed. The radial-canals are narrow and straight. The manubrium is a simple tube, which usually extends about two-thirds the distance from the inner apex of the bell-cavity to the velar opening. The mouth has 4 short lips with their edges surrounded by nematocysts. The mature eggs are found in the ectoderm of the stomach, and there they develop into actinula larvie before being set free. The entoderm of the tentacle-bulbs is intense orange. The rows of nematocysts upon the exumbrella often display an orange tinge, as does also the entoderm of the stomach. Hydroid. — The hydroid was found in Massachusetts Bay. growing in tide-pools where the water was very pure. Stems about 50 mm. in height. They grow singly, or in small clusters, and do not branch. Each stem terminates distally in a single large polypite. The stems are not more than I mm. in diameter at the base, gradually enlarging toward upper end, and are about 3 mm. in diameter at base of polypite. They are covered with a delicate sheath of chitinous perisarc, which widens and displays several well-developed annulations near the base of the polypite. The polypite is flask-shaped with a very broad base; the mouth is situated at the extremity of a narrow cylindrical neck, which is capable of much distension. There are 2 oral verticils, each composed of about 1 6 tentacles. The tentacles of the row 40 MEDUS.E OF THE WORLD. near the mouth are only about half as long as those of the lower circlet. In addition to these there are about 25 long, tapering, hollow tentacles in a zone surrounding the base of the polypite. During the breeding season, which occurs from January until May, great numbers of medusae are developed upon the sides of the polypite immediately above the circlet of basal tentacles. The budding medusae arise singly from the sides of the polypite and are not produced in clusters upon peduncles as in Hybocodon christina, H. chilensis, and H. pulcher. Longitudinal bands of orange pigment extend up the stem of the hydroid. The entoderm FIG. 10. — Hydroid, young, and budding medusse of Hybocodon prolifcr, after L. Agassiz, in Con. Nat. Hist. U. S., vol. 4. (A.) Mature hydranth. (B.) Oral eltremity of hydranth. (C.) Dissection showing intertentacular zone of medusa-buds. Remaining figures are of medusa-buds and young medusae. of the polypite is orange. L. Agassiz has shown that the entoderm of the stem is thrown into longitudinal ridges which form partial septa projecting into the cavity of the stem. The cavity, however, is continuous, and the septa do not fuse as in some other Hyboconidae. This species is found upon the New England coast. According to Browne, 1896, it is found upon the British, and also on the Irish coast, at Valencia, and off Iceland (Steen- ANTHOMEDUS.E — HYBOCODON. 41 strup) and Norway (Sars). It is apparently widely distributed over the North Atlantic, along the shores of continents and islands. It is rarely taken far from some coast. We can not be certain that the American and European forms are identical until the hydroids of both are discovered. Hargitt, 1904, states that the egg-cleavage is closely similar to that of Pennaria. Also Browne, 1895, and Hargitt, 1902, 1904, find that the ova begin their development within the walls of the manubrium of the medusa and are set free as actinulae. Muiler, 1908, and Hargitt, 1904, find that the developing embryos within the walls of the manubrium absorb their fellow ova, as has been observed by Doflein in Tuhularia mesembryanthcmurn, and by Allen in T. crocea. Developing actinulae and budding medusae are abundant at Woods Hole, Massachusetts, during the spring months. Hargitt, 1902, and Perkins, 1904, find that actinula larvae develop upon the manubrium at the same time that medusa-buds are being set free from the tentacle-bulbs. When set free the actinulae have 10 tentacles. The mouth and oral zone of tentacles develop only after the actinula is set free; and appear at the pole which was adjacent to the parent medusa during the attached period. Linko, 1905, also observed this simultaneous process of development of medusa-buds and of actinula larvae in his " Amphicodon graviJum," which develops actinulae with 1 1 tentacles. It is probably identical with H . prolifer. A single specimen was found in Barents Sea, north Russia. H. Miiller, 1908, finds that the ova are large and amoeboid. Only about 2 eggs survive to maturity in the ovary; the others having been devoured by the successful eggs. The ooplasma is a network, the exoplasma being narrow-meshed and the endoplasma wider. There are numerous pseudo-cells in degenerate stages, sometimes dividing amitotically. Hybocodon pendula Haeckel. Plate i, fig. 2. Corymorpha nutans (hydroid), STIMPSON, 1853, Marine Invert. Grand Manan, p. 9. Corymorpha pendula (hydroid), AGASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, pp. 276, 343, plate 26, 6gs. 7-17. — VERRILL, 1873, Invert. Anim., Vineyard Sound, pp. 510, 736, plate 36, fig. 273. Corymorpha pendula, HARTLAUB, 1907, Nordisches Plankton, Nr. 12, p. 85, fig. 81. — NUTTING, 1 901, Bull. U.S. Fish Commission, vol. 19, pp. 337, 370, fig. 15. — MAY, 1903, American Naturalist, vol. 37, p. 579, n figs, (histology and embryology). Corymorpha pendula (medusa), AGASSIZ, A., 1865, North Amer. Acal., p. 192, fig. 324. Hybocodon pendula, HARGITT, 1904, Bulletin Bureau of Fisheries U. S., vol. 24, p. 34, plate 2, fig. 3. Hybofodon pcndulus (medusa), HAECKEL, 1879, Syst. der Medusen, p. 34. Monocautus pendulus, ALLMAN, 1871, Monograph Tubularian Hydroids, p. 397. Adult medusa. — Bell pyriform and about 5 mm. in height. It is relatively higher than the bell of H. prolifer, and the gelatinous substance at the apex is much thicker. There are 5 rows of nematocysts upon the exumbrella, as in H. prolifer. The basal bulb of the well-developed tentacle is much smaller than in H. prolifer, and no medusa-buds have been observed to arise from it. The well-developed tentacle is 2 to 3 times the length of the bell-height. Its surface is studded with large, swollen rings of nematocysts, which give it a heavy appearance. The tentacles at the bases of the 2 intermediate radial-canals are quite well developed, and this is not the case in H. prolifer. The velum is wide and thin. The radial-canals are narrow and straight. The manubrium is longer than in H. prolifer, and extends a short distance beyond the velar opening. There is a small peduncle. The lips are thickly covered with nematocysts. Pink pigment-granules are found in the entoderm of the tentacle-bulbs. The entoderm of the manubrium is pink and lilac, and contains also some pink pigment-granules. Hydroid. — The hydroid (Corymorpha[Hybocodori\ pendula)\s found in depths of IO to IOO fathoms off the New England coast, with its base buried in the sand. It is 80 to 125 mm. in height, and 6 mm. in diameter at the widest part. It always grows singly and is never branched. The mid-region of the stem is very thick and is covered with a canaliculated coenosarc, but the basal end narrows considerably, as does also the region near the free upper extremity, which is long, slender, and pendulous. The stem is anchored by a number of root-like, tubular, fleshy processes. The perisarc exists only as a thin delicate film. The head of the polypite is large and highly contractile. There is a single verticil of long, hollow tentacles at base of polypite. The mouth is situated at the extremity of a large flask-shaped proboscis, 42 MEDUSAE OF THE WORLD. and is surrounded by a couple of rows of numerous irregularly arranged tentacles. These oral tentacles are highly contractile, and are much smaller than those at the lower base of the polypite. The medusae are borne upon branched stolon-like diverticula of the side walls of the polypite, immediately above the zone of basal tentacles. Fully-developed medusae have not been seen to be set free from the hydroid, but the similarity of the most advanced medusa- buds observed to the free medusa found in the ocean leaves but little doubt concerning this point. May, 1903, has studied the histology and embryology, and concludes that the medusa- buds may at times become free, but usually mature while still attached to the hydranth. This species has been found from Vineyard Sound to the mouth of the St. Lawrence River. The medusa appears upon the southern New England coast in April and May, but is not seen during the summer months, although the hydroid is abundant at this time. It is possible that Euphysa tentaculata Linko, 1905, is identical with H. pendula (see Zool. Anzeiger, Bd. 28, p. 214). Linko's medusa is from Barents Sea, north of Russia. I have referred to this medusa in the description of Steenstrupia bigelowt. Hybocodon forbesii Mayer. Plate I, fig. 8; plate 2, fig. 3. Hybocodon jorbesii, MAVF.R, 1894, Bull. Mus. Comp. Zool. at Harvard College, vol. 25, No. II, p. 236, plate I, fig. l; 1904, Memoirs Nat. Sci. Museum Brooklyn Institute, vol. i, No. i, p. 8, plate 2, fig. 13. Medusa. — Bell asymmetrical, about 2.5 mm. in height and ellipsoidal in shape, being slightly higher than broad. The gelatinous substance is of uniform thinness. There is a single well-developed tentacle situated at the base of the longest radial-canal. A short, conical tentacle is found at the base of the shortest radial-canal, and two smaller tentacle-bulbs are situated one at the base of each of the intermediate canals. The well-developed tentacle is about as long as the bell-diameter. Its base is small, and hardly greater in diameter than the shaft of the tentacle. Its free extremity is fusiform, and covered with prominent nemato- cyst-cells. No medusa-buds have ever been observed. The velum is narrow. The 4 radial- canals are straight and slender and the circular canal is narrow. There are no rows or clusters of nematocysts upon the exumbrella. Manubrium is spindle-shaped and swollen, and the mouth is a simple, round opening situated at the extremity of a narrow tubular neck, which extends beyond the velar opening. The entoderm of the terminal swelling of the large ten- tacle is yellow streaked with red. Entoderm of manubrium yellow with red flecks. This species is found in Nassau Harbor, New Providence Island, Bahamas, and at Tortugas, Florida, in March to May. It is an abundant surface form. I have captured many hundreds of specimens, but have never found them producing either medusa-buds or actinula larvae. It is distinguished by its decided yellow and orange color, and the absence of meridional lines of nettle-cells over the exumbrella. "Hybocodon unicus." Amphicodon unicus, BROWNE, 1902, Annals and Mag. Nat. Hist., ser. 7, vol. 9, p. 276. (?) Hybocodon chilensis (hydroid), HARTLAUB, 1905, Zoolog. Jahrbuchern, Suppl. 6, p. 545, fig. W. Bell 3 mm. high, 2 mm. wide, bell-shaped. I solitary tentacle between 2 rudimentary basal bulbs; 3 perradially situated bulbs without tentacles. Medusa-buds ( ?) Manubrium cylindrical, nearly as long as the umbrella cavity. Color ( ?) Asymmetry of bell ( ?) One specimen was found by Vallentin, and briefly mentioned without figures by Browne, from Stanley Harbor, Falkland Islands. Hybocodon chilensis Hartlaub, from the coast of Chile, may prove to be the hydroid of this medusa ( ?) It will be impossible to identify the medusa from the brief mention of it given by Browne, unless, indeed, it be rediscovered in Stanley Harbor. Hybocodon chilensis Hartlaub. Hybocodon chilensis, HARTLAUB, 1905, Zoolog. Jahrbuchern, Suppl. 6, p. 545, fig. W. (?) Amphicodon unicus (medusa), BROWNE, 1902, Annals and Mag. Nat. Hist., ser. 7, vol. 9, p. 276. (?) Steenstrupia occidentalis (medusa), FEWKES, 1889, Bulletin Essex Institute, Salem, vol. 21, No. 7, p. 107, plate 3, fig. I. Hybocodon occidenlalis, HARTLAUB, 1905, Zoolog. Jahrbuchern, Suppl. 6, p. 545. As Hartlaub states, this hydroid may be the stock of Amphicodon (Hybocodon) unicus Browne, from the Falkland Islands. ANTHOMEDUS.E — HYBOCODON. 43 The hydrocaulus is very thick and massive, about 50 mm. long and unbranched save for the presence of" its roots and stolons. It is covered with a stiff layer of chitin, which is not expanded at the base of the polypite. Polypite large, with 17 to 20 proximal tentacles, each about 6 mm. long. There are also about 27 oral tentacles arranged in several rows. Above the bases of the proximal tentacles there are 8 long, thick, medusa-bearing stolons, which are thickly covered with numerous clusters of medusa-buds. Each medusa-bud has a single very large tentacle. The stem of the hydroid is rusty yellow and the polypite light rose-color. Found at Calbuco, Chile, South America. This Hybocodon is closely related to, or possibly identical with, the form from Norway described by Bonnevie under the name Hybocodon prolifer, but it differs from H. prolifer Agassiz in having large, specialized, medusa-bearing stolons. Hartlaub proposes to call this Norwegian hydroid Hybocodon christincc. Fewkes, 1889 (Bull. Essex Inst., and also Amer. Naturalist, vol. 32, p. 597), gives a brief description of a medusa from the coast of California which he calls by two names, Steen- strupia occidentahs and S. californica; and which may be derived from Hybocodon chilensis. This medusa is described as follows: Size (?) Bell ovoid without an apical prominence. 4 (?) 5 ( ?) rows of meridional lasso-cells extend upward from the 4 tentacle-bulbs, over the exumbrella toward the bell-apex. I long tentacle and 3 rudimentary tentacle-bulbs at the bases of the 4 radial-canals. The long tentacle is ringed at regular intervals and has a large pigmented basal bulb from which there arise numerous medusa-buds. Color ( ?) Velum well developed. 4 straight, narrow radial-canals. Manubrium shorter than the depth of the bell-cavity. No axial canal. Coast of California, United States. Hartlaub proposes to call this medusa Hybocodon occidentalis. I find nothing in Fewkes's description to distinguish it from H. prolifer L. Agassiz, but apparently there is less difference between the medusas of the various forms of Hybocodon than between their hydroids. Hybocodon christinae Hartlaub. Tubular ia prolifer^ Hybocodon prolifer, BONNEVIE, 1899, The Norwegian North Atlantic Eipedition, 1876-79,70!. z6, Hydroida, p. z8, plate I, fig. 6. Hybocodon chrislin,t, HARTLAUB, 1905, Zoolog. Jahrbuchern, Suppl. 6, p. 546; 1907, Nordisches Plankton, Nr. iz, p. loz, fig. 98. The medusa attributed by Bonnevie to this hydroid has a single well-developed tentacle with a basal cluster of large medusa-buds, each bud bearing a single tentacle. The medusa- buds resemble H. prolifer, but the hydroid is distinguished by bearing its medusae upon 8 branched peduncles. Hydrocaulus unramified, tubular, springing from a ramified hydrorhiza; occurrence solitary; longitudinal striping, no collar; height about 50 mm. The hydranth has 14 proxi- mal tentacles and 2 distinct circles of (oral) distal tentacles. The oral tentacles are shorter and more numerous than the proximal. There are 8 blastostyles in a circle about midway between the oral and basal tentacles, and these bear numerous medusae upon short pedicels. The medusa-buds have 4 very wide radial-canals, and I highly developed tentacle which exhibits at its swollen base the bud-rudiments of 4 new medusae even before the first has become detached. This species is distinguished by its well-developed, branched, medusa- bearing stolons. Found off Bodo, Norway. It is closely related to H. chilensis Hartlaub, of the northern coast of Chile. The medusa-buds in H. christinie appear to be confined to the under side and the sides of the base of the well-developed tentacle. Hartlaub, 1907, finds that the medusa becomes 4 mm. high and 3 mm. wide, with thin bell-walls and an evenly rounded apex. The 4 radial-canals and ring-canal are band-like, and wider than in other species of Hybocodon. Hybocodon pulcher Hartlaub. Auliscus pulcher, SAMUNDSSON, 1899, Vid. Meddcl. Nat. For. Kjobenhavn, Ser. 6, Aarg. i, p. 4Z5, taf. 4, 7 figs. Hybocodon pulcher, HARTLAUB, 1905, Zool. Jahrbuchern, Suppl. 6, p. 545 ; 1907, Nordisches Plankton, Nr. iz, p. 96, figs. 9Z, 93. Hydroid 40 to 50 mm. high with an oral circlet of 30 short tentacles, and another circlet of 24 to 30 long tentacles around widest part of body of the hydranth. The only distinctive characters of this species are the well-developed medusa-bearing stolons, the symmetrical 44 MEDUSAE OF THE WORLD. bell, and 2 large principal tentacles of the budding medusa. In H. prolifer, on the other hand, the medusae are usually set free with but one well-developed tentacle. The bell of H. pulcher may become asymmetrical in later life ( ?) The hydrorhiza is thin and branching. There is a flexible collar-like pensarc at the base of the hydranth. Medusas are developed upon stolons from the hydranth above the circlet of long tentacles. When set free the medusa is 1.5 to 2 mm. high, of symmetrical form. 5 longitudinal lines of nematocysts extend up the sides of the bell to the apex. 3 small tentacle-bulbs. 2 equally well-developed tentacles arise side by side, from the base of one of the radial-canals. Entoderm of manubrium and tentacles red. Found off Iceland. I believe this form is probably identical with H. prolifer. Genus MICROCAMPANA Fewkes, 1889. Microcampana, FEWKES, 1889, Amer. Naturalist, vol. 32, p. 595; Bull. Essex Inst., Salem, vol. 21, No. 7, p. in. The type-species is Microcampana conica Fewkes, from Santa Cruz Island, off the coast of California. GENERIC CHARACTERS. Anthomedusae with 6 radial-canals, and 6 radially placed marginal tentacles. One of these tentacles is well developed, and the other 5 are rudimentary. It is possible that the vaguely described Rhabdoon singulare, of Keferstein und Ehlers, (1861, Zoolog. Beitrage, p. 86, taf. 13, figs. 6, 7), from Messina, Mediterranean, is a form of Microcampana, but there are apparently 12 longitudinal lines of nettling cells over the exumbrella, and it is uncertain whether there are 4 or 6 radial-canals. The bell is 1.5 mm. high and oval with uniformly thin walls. It is possibly an abnormal medusa of P elella. Microcampana conica Fewkes. Microcampana conica, FEWKES, 1889, Bull. Essex Inst., Salem, vol. 21, No. 7, p. in, plate 4, fig. 8; American Naturalist, vol. 32, p. 595, fig. Size ( ?) Bell conical with a well-developed, elongate, conical apex; slightly asymmetrical. Exumbrella smooth, without meridional rows of nematocysts. 6 marginal tentacles, 60° apart. 5 of these are rudimentary, but the sixth is club-shaped, and about half as long as the bell-height. 6 straight, narrow radial-canals and a ring-canal. Manubrium conical to spindle-shaped, about as long as the depth of the bell-cavity. There is a long, slender, straight, axial canal above the stomach. Bell pink, tentacle-bulbs bright-red, manubrium yellow. Found off Santa Cruz Island, California; under the cliffs of Punta Diablo. Genus DICODONIUM Haeckel, 1879, sens. ampl. Dieodonium+Dinemas HAECKEL, 1879, Syst. der Medusen, pp. 27, 28. ATorc Dinema, VAN BEN ED EN, 1867, Mem. Acad.Roy.des Sci.Belgique, 10111.36, art. 2, pp. 127, 130. Dicodonium, VANHOFFEN, 1891, Zool. Anzeiger, Bd. 14, p. 443. Sarsiella, HARTLAUB, 1907, Nordisches Plankton, Nr. 12, p. 66. The type-species of this genus is DicoJonium cornutum Haeckel, 1879, of the Red Sea. Dinema Van Beneden is a medusa which arises by budding from a Perigotiirnus-\\ke hydroid and therefore belongs to the Tiannae. We use the term Dicodonium in the sense proposed by Vanhoffen, 1891. GENERIC CHARACTERS. Codonidae with 2 well-developed and 2 rudimentary tentacles. No meridional lines of nettle-cells upon the exumbrella. An apical projection to the bell and an axial canal pro- jecting upward from the stomach, may or may not be present. Some of the so-called "species" of Dicodonium are probably only abnormal specimens of Sarsia with 2 tentacles instead of the normal 4. FIG. II. — Microcampana after Fewkes in Amer- ican Naturalist. PLATE 3. Fig. I. Dicodonium Jefferson:. Tortugas, Florida, June 15, 1897. Fig. 2. Sarsia rnirabilis, young medusa. Nahant, Massachusetts, March 26, 1897. Fig. 3. Hybocodon prolijer. t\ primary; t", secondary tentacle beginning to develop; m, young medusa-buds. Agassiz Laboratory, Newport, Rhode Island, September 17, 1895. Fig. 4. Sarsia mirabilis, mature male. Nahant, Massachusetts, May 7, 1897. Fig. 5. Hydroid of Sarsia mirabilis with ripe male medusa-bud attached to the hydranth. Swallows Cave, Nahant, Massachusetts, May 8, 1897. Drawn from life, by the author. PLATE 3 ANTHOMKDUS.E — DICODONIUM. 45 Tabular Description of the Medusa of DicoJonium. D. cornutum Haeckel. D. dissonema Haeckel. D. ocellatum = Dinema ocellatum Haeckel. D. floridana Mayer. D. jeffersoni Mayer. D.adriaticum Graeffe. D. dinema = Sarsiella dinema Hartlaub. Shape and size With bulging Bell-shaped to Bell-shaped Cylindrical with Dome-like Bell-shaped Half-egg- of bell in sides, and egg-shaped to hemi- dome-like 0.75 high, with a small, shaped. 3 mm. pointed with blunt spherical. 5 apex. 4 0.5 wide. conical, api- high, 2 wide. apex. 4 conical high, 4 to 5 high, 3 wide. cal projec- high, 4 wide. a prx. wide. Ex- tion. 4 high, umbrella 3.5 wide. besprinkled with tufts of nettle-cells. Length of 2 Curled up- 6 r ± lone,. 2 r lun^. v. irli 2 r long with a r long. Basal 8 r long. A 2 r + long. long tenta- ward. 3 r Verv large fairly large knob-like bulbs bear large car- Basal bulb- cles m long. A basal bulbs tentacle- swelling near ocelli. mine ocellus small; with terms of row of bns- and with an bulbs, each tip. Extreme on each ten- .'i .'Hi. bell-radius thngclusters abaxial ocel- with an ab- tip ends in tacle-bulb. «. of nettle- lus. axial ocellus. thin lash. No cells on their ocelli. abaxial sides. Tips club-shaped. Basal bulbs small. Condition of Not present. > Mere bulbs. Small, taper- Mere basal Men- basal Absent. 2 rudimen- ing, rudimen- bulbs with bulbs with tary tenta- tary. abaxial small car- cle-bulbs. ocelli. mini- "1 rill. Axial canal Well devel- Present. Not present. Not present. A small axial Not present. above stom- oped . canal is ach. presrnt. Shape of man- Spindle-shap- Spin. He-shap- Club-shaped. Flask-shaped, Cylindrical, Short, thick, Spindle- ubrium, ed. 1.5 r ed. 2 to 3 5 to 7 r widest above, with a nar- and four- shaped, and length long. Mouth times as long. but near mid- row tubular sided. 6r long. in terms of a simple wide in mid- dle. mouth-end. bell-radius round open- dle as at «• ing sur- either end. rounded bv nettle-cells. Gonail. Ring-like, swol- Large swollen Gonad en- Encircling Large gonad In stomach Encircles en- len, encir- gonad en- circles stom- stomach. encircles wall. tire stom- cling middle circles stom- ach, thickest stomach ach. third of ach. near mouth. from base to manubrium near mouth. Color. Stomach, ten- ) Bell-margin Entoderm of Entoderm of p Entoderm tacles, and rose-re, 1. stomach and stomach brownish- nettle-ring Nematocyst tentacles yel- creamy yellow. of margin clusters of low. Knoh- pink; of dark purple- exumbrella like ends of tentacle- red. black. tentacles bulbs deli- Ocelli of ten- flecked with cate green tacle-bulbs red to orange. or pink. black. Ocelli red. Where found. Red Sea, Gulf Coast of Aus- Trieste, Adria- Tortugas, Flor- Tortugas, Fla. TruMr, Adria- Normandy, of Suez. tralia. tic Sea. ida. On sur- M.iv to tic Sea. coast of face in June June, com- France. to July, rare. mon. Mediterran- ean ? Remarks. Development Development Development Development Development 1 ' • 'pment unknown. unknown. unknown. unkri"u n. unknown. unknown. Is this an Occasionally • This species abnormal rudimentary is distin- Sarsia with tentacles de- guished by only 2 ten- velop so as to stiff sensory tacies ? be almost as hairs which long as the border ocelli larger pair. 46 MEDUSAE OF THE WORLD. Dicodonium cornutum Haeckel. Dicodonium cornutum, HAECKEL, 1879, Syst. der Medusen, p. 27, taf. I, fig. 6. Haeckel found this species at Tur, near Sinai, in the Red Sea. See tabular description of medusae of Dicodonium. It has no ectodermal ocelli upon the bulbs of the 2 large tentacles. Haeckel presents a beautiful figure of the medusa, drawn from life. Dicodonium dissonema Haeckel. Dicodonium dissonema, HAECKEL, 1879, Syst. der Medusen, p. 27. Haeckel describes this from a preserved specimen from the coast of Australia. See tabular description of the medusae of Dicodonium. "Dicodonium ocellatum." FIG. 12. — Dicodonium cornutum, after Sarsia ocellata, BUSCH, 1851, Beobach. wirbellos. Seeth., p. 16, taf. 2, figs. 1-3. Haeckel, 1879. Dinema ocellatum, HAECKEL, 1879, Syst. der Medusen, p. 29. This medusa is described by Busch from Trieste, Adriatic, and it is probably an abnormal Sarsia with only 2 of its 4 marginal tentacles developed. See tabular description of the medusae of Dicodonium. Dicodonium floridana Mayer. Plate 2, fig. 5. Bell about 4 mm. high and 3 mm. wide, with thin, uniform, vertical walls and a slight apical projection. There are 2 equally-developed, diametrically opposed tentacles, each about three-fourths as long as the bell-height. Near the outer end of each of these tentacles there is a large, knob-like, swollen region, which terminates in a thin, tapering, nematocyst- bearing lash. The knob-shaped swelling is hollow and its cavity is connected with the general gastrovascular system of the medusa by means of a slender tube which extends through the entodermal core of the tentacle. The basal bulbs of the tentacles are not large, and there are no ocelli. In addition to the 2 long tentacles, there are 2 small, tapering, rudimentary tentacle- bulbs 90° from the large tentacles. The velum is well developed. There are 4 straight, narrow radial-canals and a simple, narrow circular canal. The manubrium is flask-shaped, being narrower at its base than at its middle point. The mouth projects slightly beyond the velar opening, and is a simple, round opening at the extremity of a long, tapering neck. The gonads are within the wall of the manubrium. The entoderm of the stomach is yellow, and that of the distal bulbs of the tentacles yellow flecked with orange. The entoderm of the basal bulbs of the tentacles is also tinged with yellow. This medusa is occasionally found at Tortugas, Florida, in June. Occasionally a speci- men is taken in which the normally rudimentary tentacles have developed so as to be nearly as long as the pair of large tentacles, thus illustrating the imperfect line of separation between Dicodonium and Sarsia. Dicodonium jeffersoni Mayer. Plate 2, fig. 4; plate 3, fig. I. Dinema jeflersoni, MAYER, 1900, Bull. Mus. Comp. Zool. at Harvard College, vol. 37, p. 30, plate 37, fig. 126. The bell is dome-shaped, higher than a hemisphere, and about 0.75 mm. high. The exumbrella surface is sparsely sprinkled with nematocysts. There are 2 short marginal tentacles, and 2 rudimentary tentacle-bulbs. The tentacles are radially situated, and are covered with numerous small wart-like clusters of nematocysts. There are 4 ectodermal ocelli, I upon the outer side of each of the 4 tentacle-bulbs. The velum is well developed. There are 4 straight, narrow radial-canals and a narrow circular vessel. The manubrium is about as long as the depth of the bell-cavity. It is simple, cylindrical, and tube-like, and the mouth is a round opening at the extremity of a short, cylindrical neck. A simple canal ANTHOMEDUS^E — DICODONIUM, SARSIA. 47 projects upward from the stomach into the gelatinous substance of the apex of the bell. This is probably only the remnant ot the connection between the medusa and its hydroid stock. The gonad is ring-like, and encircles the stomach, leaving the short proboscis free. The entoderm of the tentacles and tentacle-bulbs is of a delicate green or pink. The entoderm of the stomach is creamy pink. The ocelli are bright-red, and all other parts are colorless. This medusa is quite common at the Tortugas, Florida, in May and early June. Although small, it appears to be mature, for sperm is often given off from the gonad of the males. Dicodonium adriaticum Graeffe. Dicodonium adriaticnm, GRAEFFE, 1884, Arbeit. Zool. Inst. \Vien, Bd. 5, p. 551. Bell 4 mm. high, 3.5 mm. wide, bell-shaped, with a small, conical, apical projection. 2 long, radially placed tentacles, more than 12 mm. long, with large, thick, basal bulbs, each with a large carmine ocellus upon the abaxial side of the bulb. 2 tentacle-bulbs at the bases of the 2 radial-canals 90° away from the large tentacles. These basal bulbs have small red ocelli. Each of these 4 ocelli are bordered by a ring of stiff sensory hairs. There are 4 small, interradial tentacle-bulbs without ocelli. Thus there are 2 long tentacles, and 6 rudimentary tentacle-bulbs. 4 radial-canals. Stomach short, thick, and 4-sided, with the gonads in the stomach-wall. Mouth simple, with 4 lips. Found at Trieste. Adriatic Sea, in October. Dicodonium dinema. Sarsiclla dintma, HARTLAUB, 1907, Nordisches Plankton, Nr. 12, p. 67, fig. 63. Bell oval, half-egg-shaped, 3 mm. high, 2 mm. wide. Exumbrella thickly besprinkled with nematocysts. Only 2 tentacles, 1 80° apart. These are longer than the bell-diameter. They have small basal bulbs, each with a reddish-brown ocellus. No trace of tentacle-bulb or tentacles 90° apart from the well-developed tentacles. Manubrium about 2 times as long as the bell-height. Spindle-shaped and encircled throughout by the gonad. Manubrium, tentacles, and 4 radial-canals brownish-yellow. Found off the coast of Norway and in the Mediterranean ( ?) Is this an abnormal young Sarsia with only 2 tentacles ? Hydroid unknown. Medusa rare. Genus SARSIA Lesson, 1843. Sarsia, LESSON, 1843, Hist. Zooph. Acal., p. 333. — AGASSIZ, L., 1849, Mem. Amer. Acad., New Scries, vol. 4, p. 224; 1862, Cont. Nat. Hist. U. S., vol. 4, p. 211. — WAGNER, 1885, Wirbellosen des Weissen Meeres, p. 76. — VANHOFFEN, 1891, Zool. Anzeiger, Bd. 14, p. 442. — HARTLAUB, 1897, Hydromedusen Helgolands, p. 454; 1907, Nordisches Plankton, Nr. 12, p. 7. — VON LENDENFELD, 1884, Proc. Linnean Soc. New South Wales, vol. 9, p. 582. — CHUN, 1895, Bibliothcca Zoologica, Bd. i, Heft. 19, p. 4. — GOETTE, 1904, Zool. Anzeiger, Jahrg. 27, p. 473. Coryne + Syndictyon, AGASSIZ, A., 1865, North Amer. Acal., p. 175. Coryne (hydroid), CALKINS, 1899, Proc. Boston Soc. Nat. Hist., vol. 28, p. 336. Codonium + Sarsia + Svndictvon, HAECKEL, 1879, Syst. der Medusen, pp. 13, 16, 20. Syncoryne, WEISMANN, 1883, Entsteh. Sexualzellen Hydromedusen, pp. 56, 216. Syncoryne (hydroid), HARTLAUB, 1905, Zool. Jahrbuchern, Suppl. 6, p. 524. — NUTTING, 1901, Proc. Washington Acad. Sci., vol. 3, p. 165. Syncoryne (medusa), HARGITT, 1904, Bull. U. S. Bureau of Fisheries, vol. 24, pp. 29, 30. Syncoryne, BEDOT, 1905, Revue Suisse de Zool., tome 13, p. 119 (citation of all references to 1850). SynJiclon, AGASSIZ, A., 1862, in L.Agassiz's Cont. Nat. Hist. U. S., vol. 4, p. 340. — MAYER, 1904, Mem. Nat. Sci. Museum Brook- lyn Institute, vol. i, p. 7. Stenyo, DUJARDIN, 1845, Annales Sci. Nat., ser. 3, tome 4, p. 257. The type-species of this genus is Sarsia tubulosa of the northern coasts of Europe. This medusa was first described by Lesson, 1843. The hydroid form was first described by Gartner, 1774, in Pallas's Eleunch. Zooph., under the name of Coryne. Ehrenberg, Sars, and Allman introduced the name Syncoryne. Staurtdia producta also gives rise to a medusa which can not be distinguished from Sarsia. GENERIC CHARACTERS. Codonidae with 4 long, simple, equally developed tentacles, I at the foot of each radial- canal. The manubrium is tubular and surrounded by a ring-like gonad. There is an ectodermal ocellus upon the outer side of each tentacle-bulb. There are no meridional nematocyst-tracts upon the exumbrella. 48 MEDUSA OF THE WORLD. An apical projection of the bell may or may not be present; and there may or may not be an axial canal extending upward from the stomach into this projection. The hydroid is Syncoryne or Staundia. We use the name Sarsia in the sense defined by Vanhoffen, 1891 (Zool. Anzeiger, p. 442). In 1862, 1865, A. Agassiz described, under the generic name Syndictyon, a Sarsia having reticulate nematocyst-cells upon its exumbrella, and clusters of such cells upon its tentacles. These are, however, only characters of immaturity and largely disappear in the full-grown medusa, which is a true Sarsia in all respects. In 1879, Haeckel formed the genus Codonium to include medusae resembling Sarsia but distinguished by the possession of an apex upon the bell into which a blindly-ending axial canal extends from the stomach. A bell-apex and axial canal are characters which are acquired during growth in varying degrees by almost all species of Sarsia, and are therefore not of generic value. Two European and one American species of Sarsia produce medusae by asexual budding from the tentacle-bulbs or from the walls of the manubrium. Chun, 1895 (Bibliotheca Zoo- logica, Heft 19, fig. 2), showed that both ectoderm and entoderm of the manubrium take part in the formation of these proliferating medusae; the entoderm of the manubrium forming the entoderm of the daughter medusa, and the same being true of the ectoderm. Sarsia prolifera Forbes, described and beautifully figured by Haeckel, 1879, under the name Codonium codonophorum, produces medusa-buds upon its tentacle-bulbs. The majority of Sarsia medusae are probably produced asexually by hydroids of the genus Syncoryne, but at least one medusa identical with Sarsia is derived from the hydroid called Staundia Dujardin, 1843. Such medusae may conveniently be placed in a subgenus Staundwsarsia. A medusa which appears to be closely related to Sarsia is produced by the remarkable parasitic hydroid Hydrichth vs. The generic name Syncoryne was restricted by Allman, 1871-1872, to designate the hydroid which produces the medusa Sarsia. The name Syncoryna was first proposed by Ehrenberg, who applied it to hydroids now known as Clava, Coryne, etc., and in this old sense it does not apply exclusively to the hydroid of Sarsia. By general consent, Allman's name has been accepted in this restricted sense, Calkins, 1899, being almost alone in main- taining that the generic name of the hydroid should be Coryne. The commonly accepted arrangement is to retain the old name Coryne to include hydroids in which the reproductive elements are produced in fixed sporosacs growing upon the hydranth, while Syncoryne applies to like hydroids which, however, produce free medusae. Weismann, 1883, found that the germ-cells of both sexes of Syncoryne sarsii originate in the ectoderm of the budding medusa, and do not wander from their place of origin, but become mature in the free medusa. Goette, 1904, finds, however, that in Sarsia the sperm originates and remains in the peripheral ectoderm of the manubrium of the medusa, but the pgg-cells, contrary to Weismann's contention, originate in the entoderm of the medusa-bud while it is still attached to the hydroid, but afterwards they migrate into the ectoderm of the manubrium, where they mature. Many of the species of Sarsia display considerable individual variability, the colors of the manubrium and tentacle-bulbs ranging from green or yellow to red. An apical pro- jection and an axial vessel above the stomach may or may not be developed, and the length of the manubrium at maturity is subject to much variability. Moreover, the hydroids may form densely or sparingly branched colonies in accordance with environmental conditions, and as is well known in S. mirabihs, free medusae are produced in early spring, whereas late in the season the medusae mature while still attached to the hydroids. Much contusion has been introduced into the synonymy of the genus, and different stages of the same medusa have occasionally received different specific names. Sarsia " nodosa" Busch, 1851, appears to be the young of some European Sarsia. The exumbrella of very young medusae of Sarsia are usually besprinkled with nettling cells and their tentacles bear prominent nematocysts, and Busch's medusa displays both of these characters. (See Hartlaub, 1907, Nordisches Plankton, Nr. 12, p. 68, fig. 64.) ANTIKIMKDrs.K — SAKSIA. 49 Tubular Description of the Medusa of Sarsia. S.tubulosa Lesson, i843*. S. mirabilis L. Agassiz •»49-t S. eximia = Syncor- yne eximia Hincks, 1868. S.radiata von Lrndenfeld. S. conica= Codon- ium conicum Haeckd. Shape and size of Egg-shaped. Half- As in S. tubulosa, 7 to Oval with quite Semi-ovate. 3 Barrel-shaped with bell in mm. ellipsoidal. loto 10 high, 4 to 8 wide. thick walls. 3 high, 2. 5 wide. long p< 12 high, 6 to 8 high. 2 wide. apex. 12 high, 4 wide. With or wide. without apical projection. Character of 4 ten- Basal bulbs small; As in S. tubulosa. Basal bulbs large, As in S. eximia 7 r long, with small tacles. Length each with abaxial with abaxial ocel- basal bulbs. in terms of boll- ocellus. Tentacles lus on each. Ten- radius (r). about 4 to 6 r tacles about 4 r long, and without long- prominent clusters of nettle-cells. Shape and length Narrow, cylindrical Narrow tubular base. Cylindrical; wide As in S. eximia, Spindle-shaped, of manubnum at its base. Mid- Mid-region swollen and above, with nar- i .5 r long or only 1.5 to 2 r in terms of bell- dle part cylindri- cylindrical. Line of row, short, tubular less. long. radius (r). cal, swollen by demarcation between neck above mouth gonad. Stomach narrow, cylindrical, Length about 2 r small, spindle- basal, and wide middle or less. shaped. Mouth at part very sharp. end of short coni- Stomach swollen and cal neck, as in spindle-shaped and S. mirabilis. near outer end of tin- Length 4 r. manubrium. Beyond stomach there is a short, tapering, narrow neck. Mouth is a round opening. Total length 3 to 6 r. Average 4 r. Gonads. Ring-like and de- Thick ring encircling Encircles manu- As in S. eximia. Encircles stomach, veloped over manubrium. Begin- brium from base leaving both ends nearly the whole ning abruptly at a short to mouth end, free. length of the distance from base, leaving only short manubnum, leav- and extending to upper neck above the ing a short dis- part of stomach, leav- mouth free. No tance at both ends ing both ends of man- medusa-buds. free. No medusa- ubnum free. buds. Color. Entoderm of stom- Entoderm of stomach Entoderm of stom- Entoderm of ? ach green, bluish usually green, some- ach yellowibh- manubrium lilac, or red- times green and red, red to reddish- and tentacle- Tentacle-bulbs or red. Tentacle-bulbs brown or green. bulbs deep green, blue, or red. green or red. Ocelli Ocelli black in brown. Ocelli black. black. young and ml m mature medusa. TentacJe-bulbs red, or brownish- red. \Vhere found. North Atlantic From coast of New Jrr- Coast of England, New South Indian (Kc.m. coasts of Europe scv northward to Arctic S( ntland, Helgo- W.ilrs, Aus- to Arctic Ocean. Ocean. Coasts of Nor- land, Nnnvav, tralia. wav. northern Russia, Juneau, Alaska, Greenland, Alaska to North Pacific northern Chile along (Nutting). Pacific coast to South America. Hydroid. Syncoryne sarsia Svnotrvne "miraluli " Svncoryne eximia, Sviu i>rvnr r.uli- 1'iikrmwn. Loven. Hartlaub, L. Agassi/,. S. reticu- Allman. aba. 1905, describes lata is a closely related (this hvdroid ?) variety (see text). from Terra del Fuego, Antarctic. *Description based on accounts by European writers. j-Description based on original observations of medusa: found off southern coast of New England, United States. 50 MEDUS/E OF THE WORLD. A number of Syncoryne hydroids have been described which probably produce Sarsia medusae, but are not known so to do. Among these may be mentioned Syncoryne crassa Pictet, 1893 (Revue Suisse Zool., tome I, p. 8), a small hydroid only 2 mm. high and rela- tively thicker and shorter than S. pulchella of Allman, 1871 (Monog. Tubularian Hydroids, p. 279, plate 6, fig. 3). Pictet's hydroid comes from Amboina, Malay Archipelago. It has 30 to 40 short, knobbed tentacles, and the medusa-buds arise singly between the tentacles. The hydrorhiza is net-like, and the hydroid is pale orange in color. Hartlaub, 1907, has made a masterly study of the genus Sarsia, and shows that the species fall conveniently into two groups: the Eximia group, with short manubrium occupied entirely by the gonad, which extends from its base to near the mouth, and the Tubulosa group, Tabular Description of the Medusa of Sarsia. — Continued. S. prolifera Forbes = S. codono- phora Haeckel. (See text.) S. gemmifera Forb. = S. siphono- phora Haeckel. S.hargitti = S.pro- ducta Hargitt. S. flammea Hart- laub, 1907. Sarsia (Stauridio- sarsia)producta = Stauridiaproducta Wright, Hartlaub. Shape and size of Bell-shaped, with Bell ellipsoidal. Pyriform. 1.5 high, Oval. 12 high, 7 Three-fourths-egg- bell in mm. or without apical 8 high, 6 wide. i wide. wide. shaped. 10 high, projection. 2.5 7 wide. to 8 high, 3 to 8 wide. Character of 4 ten- Basal bulbs very Well-developed Well-developed Tentacle tips knob- Large basal bulbs tacles. Length large and wide, basal bulbs with basal bulbs with like. Shafts cover- with abaxial ocelli. in terms of bell- with black or red abaxial ocelli. abaxial ocelli. ed with broken Tentacles about 3 radius (r). ocelli. Tentacles Tentacles4r long. Tentacles ir long. (partial) rings. to 4 r long. hollow, tapering. No ocelli. 2 to 6 r long; with clusters of medusa-buds upon their bases. Shape and length Spindle-shaped with Very long, tubular, Spindle-shaped at Conical — spindle- Cylindrical, about of manubrium narrow neck and with spindle- both ends, narrow- shaped, only two- 3 r long. in terms of bell- simple, round shaped stomach er and tubular in thirds as long as radius (r). mouth-opening. near outer end. middle. 2 to 3 r the depth of the About i .5 r long. Mouth at extrem- long. A circlet of bell-cavity. ity of narrow medusiform neck. Manubrium gonads( = medusa- 8 r long. buds ?) near prox- imal end of man- ubrium. Gonads. Encircling stomach. Gonad ( ?) Gonad ( ?) Ring-like, encirc- Gonad at base of Medusae pro- Medusae produc- Medusiform buds ling the manu- stomach. No me- duced asexually ed asexually by on stomach in cir- brium from its dusa-buds. upon the tentacle- budding from clet near base. base to near bulbs. sides of manu- mouth. brium. There may be 10 to 22 or more of these budding medusae upon manubrium at one and same time. Law of bud- ding discussed in text. Color. Entoderm of tenta- Entoderm of stom- Basal part of manu- Entoderm fiery red Stomach brownish, cles and stomach ach, tentacles, and brium orange. or orange. gonads yellowish- yellow to sage- radial-canals or- Distal end blue- white, tentacle- green. Mouth or- ange-yellow to or- green. Tentacle- bulbs red. Ocelli ange. Ocelli ange-red. Ocelli bulbs orange, black. brown. Tentacle- black. edged with green. bulbs contain red Ocelli black. entodermal pig- ment. Where found. English Channel to Atlantic coasts of No Man's Land, Arctic Ocean. Coast of Great Mediterranean. Europe, from near Woods Hole, Britain to Helgo- Norway south- Massachusetts, land. ward to Canary United States. A Islands. single specimen was found. Hydroid. Unknown. Unknown. Unknown. Stauridia producta. ANTHOMEDUS.E — SARSIA. 51 with long, tubular manubrium with the gonad confined to a short length near its free outer end. He states that the Eximia group are represented by such forms as Sarsia eximia, brachygaster, flarnmea, barentst, prolijera, angulata, and apiculata. The Tubulosa group are represented by S. tubulosa, Jensa, decipiens, litorea, pulchella, frutescens, mirabilts, reticulata, princeps, rosaria, etc. The genus Plotocnide Wagner, 1885, is defined by Hartlaub, 1907, as a Sarsia-Kks medusa with nettle-cells upon the exumbrella. The gonad surrounds the manubrium from the base downward. No ocelli. Hydroid unknown. It appears to me that unless it be proven that the hydroid is different from Syncoryne, this genus should be merged with Sarsia. Weismann, 1881 (Zool. Anzeiger, Bd. 4, p. 61), shows that the circulation of fluids within the gastrovascular cavity of Coryne pusilla is aided by the rhythmical contraction of the walls of the gonophore. The systole and diastole are not always of equal duration, but each ranges from 60 to 75 seconds. Thus the circulation in certain hydroids may be aided by periodic peristaltic contractions as well as by the movement of cilia. Annandale, 1907, Journal and Proc. Asiatic Society of Bengal, vol. 3, finds Syncoryne filarnentata, sp. nov., developing free medusae and growing in brackish pools of one-third the salinity of sea water at Port Canning, Lower Bengal. The mature medusa is unknown. Tabular Description of the Medusa of Sarsia. — Continued. S. rosaria= Coryne rosaria A. Agassiz, 1865. S. minima von Lendenfeld. S. brachygaster Gronberg, 1898. S. angulata Mayer. S. gracilis Browne, 1902. S. princeps Haeckel, 1879. Shape and Oval, with small Ovate. 3 high, Three-fourths- Half-egg-shap- Cylindrical, Conical with thin size of bell apical projection. 2.5 wide. egg-shaped, ed. 3 High, thick-walled. walls. 281040 in mm. 15 to 30 high, 10 widest above 2.8 wide. 4- 5 high, 3 wide. high, 15 to 30 to 15 wide. the middle. 15 sided in con- wide. to 18 high, 8 traction. to 10 wide. Character of Basal bulbs large; Tentacles about Basal bulbs Basal bulbs Ocelli on basal Basal bulbs 4 tentacles. each with abaxial 2.5 r long. large with a large, with well- bulbs. Each elongate, con- Length in ocellus. Tentacles small abaxial developed ab- tentacle 3 r ical, and Banked terms of 3 to 4 r long. ocellus. Ten- axial ocellus. long, termina- by pad-like clus- bell-radius Basal bulbs tacles 3 to 4 Tentacles z r ting in a ni-nia- ters of nemato- (r). flanked by pads rlong. long- tocyst-knob. cysts. Each bulb of nettle-cells. bears small ab- axial ocellus. Tentacles 8 r long. Shape and Spindle-shaped, As in S. rosaria. As in S. eiimia. Shaped as in S. Two-thirds as Tubular, cylin- length of only 1.510 2 r long. rosaria. r to long as the drical, with a manubrium one-twelfth r depth of the round mouth- in terms of long. bell-cavity. opening 4 r bell-radius long. (r). Gonads. Encircles stomach, As in S. rosaria. As in S. eximia. As in S. rosaria. CO As in S. rosaria. leaving both ends free. No medusa- buds. Color. Entoderm of stom- Entoderm Entoderm of Entoderm of (0 Entoderm of ten- ach ranges from brown. stomach and stomach and tacle-bulbs and yellow to pink or tentacle-bulbs tentacle-bulbs manubrium pur- reddish-brown to orange-red. robin-egg ple. Ocelli purple. Tentacle- Ocelli black. blue; never black. bulbs yellowish- red. Ocelli brown to red. deep-brown. Where found. Pacific coast of Port Jackson, Spitzbergen and Bahamas to Stanlev Harbor, Greenland and North America, New South Greenland, in Tortugas, Falkland Is- Spitzbergen, in southern Califor- Wales, Aus- summer. Florida. Win- lands. summer. nia to Puget tralia. ter to mid- • Sound . summer. Hydroid. Syncoryne rosaria Syncoryne min- Unknown. Unknown. (? 0 Unknown. A. Agassiz and ima. Syncoryne sar- Fewkes. sii Hartlaub, 1905(0 1= this medusa a young Slab- beria ? 52 MEDUS.E OF THE WORLD. Sarsia tubulosa Lesson. Syncorvna sarsii (hydroid), LOVEN, 1835, K. Vet. Acad. Handl. for Ar., p. 275, plate 8, figs. 7-10. Oceania tubulosa (medusa), SARS, M., 1835, Beskriv og Jagtt., p. 25, plate 5, fig. 1 1 . Also: Syncorine sarsii, 1846, Fauna littor. Noveg., part. 2, p. 2, tab. i, figs. 1-6. Syncoryne sarsii, LOVEN, 1837, Archiv. fur Naturgesch., Jahrg. 3, p. 321, taf. 6, fig. 25. — WEISMANN, 1883, Entsteh. Sexuabellen bei Hydromedusen, Jena, pp. 56, 216. — GARSTANG, 1894, Journal Oxford Club, vol. 2, No. 30, p. 7. — CITRON, 1902, Archiv. Naturges., Jahrg. 68, pp. I, 26, taf. i, 2 (sensory cells of tentacles). — HINCKS, 1868, British Hydroid Zoophytes, p. 52, plate 7, fig. 3. — ALLMAN, 1872, Monog. Tubularian Hydroids, p. 275. Syncoryne sarsi and Sarsia tubulosa, BEDOT, 1905, Revue Suisse de Zool., tome 13, pp. 120, 147 (all literature 1835-1850). Sarsia tubulosa, LESSON, 1843, Hist. Zooph. Acalephes, p. 333. — SCHI'LZE, 1873, Ueber den Bau von Syncoryne Sarsii, p. 14, taf. 3.— ROMANES, 1885, Jellyfish, Star-fish, and Sea Urchins, etc., International Scientific Series, vol. 49 (reactions to stimuli). — LINKO, 1905, Zool. Anzeiger, Bd. 28, p. 212. — HARTLALIB, 1907, Nordisches Plankton, Nr. 12, p. 19, figs. 10-16. — BROWNE, 1903, Bergens Museums Aarbog, No. 4, p. 9; 1895, Proc. and Trans. Liverpool Biol. Soc., vol. 9, p. 246. Sarsia tubulosa, SARS, i$$$=Sarsia macrorhyncha, BUSCH, 1851; BROWNE, E. T., 1905, Proc. Royal Soc. Edinburgh, vol. 25, p. 758. Syncoryne gravata, HINCKS, 1868, Hist. British Hydroid Zooph., p. 53. Sarsia tubuhsa+S. macrorhyncha, HAECKEL, 1879, Syst. der Medusen, pp. 16, 19. Sarsia tubulosa + S. pulchella, FORBES, 1848, British Naked-eyed Medusa-, pp. 55, 57, plate 6, figs. ^, 3. Corynt pusilla, AGASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 340. (!) Syncoryne Sarsii, HARTLAUB, 1905, Zoolog. Jahrbiichern, Suppl. 6, p. 525, fig. F (hydroid from Terra del Fuego). Sarsia macrorhyncha, BUSCH, 1851, Beobach. wirbell. Seeth., p. lo, taf. 3, figs. 7-10; taf. 4, figs. I, 2. FIG. 13. — "Sarsia litorea," after Hartlaub, in Nordisches Plankton. FIG. 14. — "Sarsia decipiens," after Hartlaub, in Nordisches Plankton. FIG. 15. — "Syncoryne gravata," after Hincks, in British Hydroid Zoophytes — probably hydroid of Sarsia T^l- ' . _J ' r 1 _£T^l__ TT 1' t_ . - _1 ' ^1_ - ! L..^ :^ J' _ mirabilis This medusa is found off the English coast early in the spring, but it disappears before August. It is evidently an Arctic species, is abundant off the northern coasts of Europe, and is found off Iceland. It is very closely related to, if not identical with, the American S. mirabilis, but may possibly be distinguished by its more slender and higher bell, its very long manubrium, and its somewhat shorter tentacles. All of these characters are, however, very variable in Sarsia mirabilis, and I have become convinced that the American and European forms are at most only varieties, one of the other. For details see the tabular description of medusae of Sarsia. Romanes, 1885, carried out many interesting physiological experiments upon this species, and showed that its ocelli are organs for the perception of light. The medusa is sensitive only to rays between the red and violet, and is strongly attracted by the light. The smallest part of the bell-margin is capable of initiating and maintaining the rhythm of the bell, but if the margin be entirely removed all pulsations of the bell instantly cease, while the cut-off margin continues to pulsate. Stimulation of the subumbrella of the bell causes contraction of the manubrium (proboscis), and indeed the bell, when deprived of its margin, still responds by contractions to all sorts of stimuli, chemical, thermal, electrical, or mechan- ical, although sustained rhythmical pulsation is never resumed. The hydroid is Syncoryne sarsii, which is common in shallow water along the coasts from England to Norway. The polypites are spindle-shaped and elongate and have about 12 to PLATE 4. Fig. i. Sarsta mirabilts. Abnormal medusa with a tentacle arising from the side of the manubrium. Nahant, Massachusetts, May 8, 1897. Metschnikoff, 1870, observed a similar abnormality in Slabbena catenata. Fig. 2. Median section of a young medusa of Sarsia mirabilis. The ocellus on the right-hand tentacle is shown as if depigmented in order to illustrate its structure. The eye on the left-hand tentacle-bulb is shown normally pigmented. Figs. 3 and 4. Sarsia mirabilis var. reticulata, young medusa. Figure 4, one of the nematocyst-cells from the tentacles of figure 3. Agas- siz Laboratory, Newport, Rhode Island, June 13, 1895. Drawn from nature, by the author. ANTHOMEDUS.E — SARSIA. 53 16 short tentacles which arise at irregular intervals from their sides. Each of these tentacles ends in a knob-like cluster of nematocysts. The 2 or 3 medusa-buds arise from the sides of the polypite between the tentacles. The stems of the hydroid are quite smooth, sparingly branched, and about 12 to 15 mm. high. The stems are translucent, slightly horny in color, and the polypites are light-red. I can not determine any well-defined distinctions between S. sarsii and S. mirabtlis, excepting that in S. sarsn the medusa-buds appear always to arise from near the middle of the sides of the polypite between the tentacles, whereas in S. mirabilts the medusa-buds arise from near the base of the polypite at or below the level of the lowest zone of tentacles. Hartlaub has given excellent figures and descriptions of a number of medusae which are closely related to Sarsia tubiilosa, if not mere varieties of the latter. These are S. pattersoru Haddon, S. frutescens Allman, 5. decipiens Hartlaub, S. litorca Hartlaub, and S. pulchella Forbes. (See Hartlaub, 1907, Nordisches Plankton, Nr. 12, pp. 29, 30, 32, 36; figs. 20-226, 23, 24, 28, 29.) I hesitate to quote these as distinct species, for I have observed the same or nearly the same variations among individuals in swarms of S. mirabilis at Nahant, Woods Hole, and Newport on our coast. A statistical study, or better still, a study of the respective hydroids, is required before we can hope to determine these so-called "species" with certainty. Garstang, 1894, observes that the hydroid of S. tubulosa gives rise to dimorphic medusae, as does S. mirabilis on the coast of New England, where early in the spring the medusae are set free, whereas in May they mature while still attached to the hydroid. Sarsia tubulosa Lesson, variety Sarsia mirabilis L. Agassiz. Plate 3, figs. 2, 4, and 5; plate 4, figs. 1 and 2. LITERATURE RELATING TO THE AMERICAN VARIETY or SARSIA TUBULOSA. Sarsia mirabilis, AGASSIZ, L., 1849, Mem. Amer. Acad., New Ser., vol. 4, p. 224, plates 4, 5. — STIMPSON, 1853, Marine Invert. Grand Manan, p. u. — HAECKEL, 1879, Syst. der Medusen, p. 17. — FEWKES, 1881, Bull. Mus. Comp. Zool. at Harvard Coll., vol. 8, p. 141, plate 3, figs. 1 1, 12. — LEVINSEN, 1893, Vid. Meddel. Nat. For. Kjobenhavn (5), Bd. 4, p. 143. — BIR- ULA, 1896, Annuaire Musee Zool. Imp. Sci. St. Petersbourg, tome I, p. 332. — HARTLAUB, 1907, Nordisches Plankton, Nr. 12, p. 37, figs. 30-40. — LINKO, 1900, Mem. Acad. Sci. St. Petersbourg, ser. 8, vol. 10, No. 4, p. u, taf. I, figs. 1-12 (structure of ocelli); 1905, Zool. Anzeiger, Bd. 28, p. 212; 1900, Traveaul Soc. Jmperiale des Nat. St. Petersbourg, torn. 29, p. 151. Sarsia mirabilis (medusa), AGASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, pp. 21 1-217; vol. 3, Ibid., plate 18, figs. 15-250. Sarsia glafialis, MORCH, 1857, Beskriv af Gronland, p. 95. Corync mirabilis (hydroid), AGASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, pp. 185-21 1, plates 17-19; vol. 3, Jbid., figs. 1-16, plate 17; figs. 1-14, plate 18; figs. 1-27, plate 19. Corvnt mirabilis, AGASSIZ, A., 1865, North Amer. Acal., p. 175, figs. 282-285. — CALKINS, 1899, Proc. Boston Soc. Nat. Hist., vol. 28, p. 336. Oceania lubulosa, GOULD, 1841, Invert, of Mass., p. 348. Syncorvnt mirabilis, ALLMAN, 1871, Monog. Tubul. Hydroids, p. 278. — HARGITT, 1904, Bulletin Bureau of Fisheries U. S., vol. 24, p. 30, plate v, fig. i; 1901, Amer. Naturalist, vol. 35, p. 578, fig. 33; 1903, Science, vol. 16, p. 344 (variations). — HARTLAUB, 1905, Zool. Jahrbuchern, p. 526; Zool. Jahrb., Syst. Abth., 1901, Bd. 14, p. 356. — TORREY, 1902, Univ. California Publications, vol. I, p. 31. — NUTTING, 1901, Bull. U. S. Fish Commission, vol. 19, pp. 328, 372, figs. 3, 81. ( ?) Syndictyon angulatum (young medusa), MURBACH and SHEARER, 1903, Proc. Zool. Soc. London, vol. 2, p. 168. (})Sarsi barfnisii (young red-colored medusa), LINKO, 1905, Zool. Anzeiger, Bd. 28, p. 214 (north of Russia). ( ?) Euph\sa tentaculata (abnormal medusa with only 3 well-developed tentacles), LINKO, 1905, Zool. Anzeiger, Bd. 28, p. 214 (Barents Sea, North Russia). Syncoryne densa, HARTLAUB, 1897, Wissen. Meeresuntersuch. Komm. Meere. Kiel, Helgoland, Neue Folge, Bd. 2, p. 452, taf. 166, figs. 4, u ; taf. i6r, figs. 7, 8 (hydroid forms dense tufts). Also: Sarsia sp., HARTLAUB, 1896, Verhandl. Deutsch. Zool.Gesell., Leipzig, Bd.6, Vers., p. 182 (medusa; with branched manubria); 1907, Nordisches Plankton, Nr. 12, p. 26, figs. 17-19, 22a (hydroid and medusa). The following description is derived from a study of medusae and hydroids obtained off the southern coast of New England, United States. Adult medusa. — Bell is half-egg-shaped, about 7 mm. in height and 4 mm. in diameter. There is no apical projection, and the gelatinous substance is not very thick at the aboral pole and becomes successively thinner near the margin. There are 4 long, highly contractile tentacles, one at the base of each .radial-canal. The surface of each tentacle is covered with prominent nematocyst-cells, which are clustered especially at the outer end of the tentacle. Each tentacle arises from a well-developed basal bulb which contains a single ectodermal ocellus upon the outer nerve-ring on the abaxial side of the tentacle-bulb. According to Linko, 1900, the ocellus is composed of a cup-shaped invagmation of densely pigmented ectodermal cells between which there are spindle-shaped bipolar nerve-cells. The ento- 54 MEDUSAE OF THE WORLD. dermal core of the tentacle is hollow, and its lumen is continuous with the gastrovascular system of the medusa. The ectodermal cells of the tentacle-bulb are very thick and are probably nervous in function. The velum is well developed, being wide and thin. There are 4 straight, slender radial-canals, and a simple, narrow, circular tube. A short, blindly- ending tube extends upward from the base of the stomach into the gelatinous substance of the bell. The entodermal cells of this small projection are several layers thick. The manubnum is long and extends far beyond the velar opening. Its proximal part is slender and tubular, but in its outer parts it is much distended by the genital products and consists of a long, wide, cylindrical tube. The line of demarcation between the narrow and the wide part of the manubrium is very sharp. The mouth is a simple opening at the extremity of a short flask-shaped proboscis, and the lips are studded with nematocysts. The mature genital pro- ducts are found in the ectoderm of the distal part of the manubrium. The entoderm of the manubrium is usually green, but occasionally it is red. The entoderm of the tentacle- bulbs is either red or green, and in some individuals the entoderm of the bulb is red while the ectoderm is green. FIG. 16. — "Syncoryne pulchella." FIG. 17. — "Syncoryne frutescens." The above figures are after Allman, in Ray Society, 1871-72. Hydroid and young medusa. — The hydroid stock is Syncoryne mirabilis. The stems are attached by a creeping stolon. They are about 15 millimeters in height and branch profusely. The main stems and also the side branches terminate each in a single polypite. The stems are incased in an unannulated chitinous perisarc, which terminates sharply at the bases of the polypites. Each polypite is fusiform and has about 12 to 18 tentacles which arise in 3 or more indefinite whorls from the sides of the polypite. These tentacles are not long, but are quite contractile. Each terminates in a knob-shaped cluster of nematocyst- cells. The mouth of the polypite is a simple round opening situated at the extremity of a conical proboscis. Medusa-buds are developed upon the sides of the polypites immediately below the tentacles, near the lower base of the polypite. Each polypite bears I to 4 medusa-buds in various stages of development. In Massachusetts Bay the breeding season begins early in March and lasts until the end of May. During March the medusa-buds ANTHOMEDUS.E — SARSIA. 55 develop 4 long tentacles, and are set free in an immature state, but during the last half of the breeding season they fail to develop tentacles or give rise to mere short lashes upon their basal bulbs; and they become sexually mature while attached to the hydroid, the manubrium of each bud being greatly distended with the genital products. This observation was first made by L. Agassiz, 1862 (pp. 189, 203), and has been confirmed by us in hydroid stocks obtained in Swallow's Cave, Nahant, Massachusetts. Plate 3, fig. 5, is derived from one of these sexually mature medusa-buds found upon a hydroid on May 8, 1897. It will be observed that the manubrium of the bud is distended with sperm, while the tentacles are not developed. In this connection it is interesting to observe that Pennaria and Podocoryne carnca sometimes give rise to medusae which are sexually mature at their time of liberation, while in other stocks of the same species the medusae are set free in an immature condition. Garstang, 1894, observes the same phenomenon in the European S. sarsii. This hydroid of our Sarsia is very abundant, from March until May, in Massachusetts Bay, where it appears to grow equally well both in pure sea-water and in the brackish mouths of rivers. The medusae appear in great numbers on the southern coast of New England FIG. 18. — Hydroid and medusa of "Sarsia Jensa," after Hartlaub, in Nordisches Plankton. between February and April. They become rare during May, and are not seen during the summer months. The hydroid extends northward to the Greenland coast, but has not been recorded from Beaufort, North Carolina, or farther south. Linko and Birula, 1896, found it in the White Sea, and Linko, 1905, records it from the eastern parts of Barents Sea between Kanin and Kolgujew Islands. Calkins, Torrey, and Hartlaub have found this medusa along the Pacific coast of America as far south as Chile. I believe Syncoryne densa Hartlaub from Helgoland to be an environmental form of S mirabilis. We have observed an abnormal medusa of Sarsia mirabilis in which a single well- developed tentacle arose from the side of the manubrium at the point of juncture of the long tubular basal region and the gemmiferous part of the manubrium. (See plate 4, fig. i). This abnormal tentacle was studded with clusters of nematocyst-cells. It lacked a basal bulb and had no ocellus. Asexual budding of medusa- from the walls of the manubrium is not known in Sarsia mirabilis. Medusae of Sarsia with branched manubria are described by Hartlaub, 1896, 1907. Professor Hartlaub finds that in Sarsiti mirabilis the stomach is confined to the distal end of the manubrium and the gonad is confined to the mid-region of the manubrium above the stomach. Both the proximal and distal ends of the manubrium lack the gonad. On the other hand, in S. brachygaster and S. cximia there is no differentiated stomach-region, and the gonad may extend over the whole, or nearly the whole, length of the rnanubrium. 56 MEDUSAE OF THE WORLD. The chief and possibly only well-marked point of difference between the forms S. mira- bilis and S. tubulosa is that in the hydroid of S, mirabilis the medusa-buds arise from near the base of the polypite, whereas in the hydroid of 5. tubulosa they arise from points higher up on the sides of the polypite, between the tentacles. 20. FIG. 19. — Sarsia eximia, after Hartlaub, in Nordischcs Plankton. FIG. 20. — Syncoryne eximia, after Allman, in Ray Society, 1871-72. Hydroid'and young medusa. PLATE 5. Fig. I. Sarsia angulata. Nassau Harbor, New Providence Island, Bahamas, July, 1903. Fig. 2. Corynitis agassizii. Charleston Harbor, South Carolina, September, 1897. Fig. 3. Ectopleura minerva. Tortugas, Florida. Fig. 4. Ectopleura dumortieri, young medusa. Agassiz Laboratory, New- port, Rhode Island, June, 1893. Fig. 5. Ectopleura dumortieri, mature male. Agassiz Laboratory, Rhode Island, July, 1896. Fig. 6. Sarsia mirabilis var. reticulata. Nahant, Massachusetts, March 25, 1897. Drawn from life, by the author. PLATE 5 AXTHI i.MKDTS.E SARSIA. 57 Sarsia mirabilis var. reticulata. Plate 4, figs. 3 and 4; plate 5, fig. 6. Syndictyon reticulatum, A. AGASSIZ in L. AGASSIZ'S, 1862, Cont. Nat. Hist. U. S., vol. 4, p. 340. — AGASSIZ, A., 1865, North Amer. Acal., p. 177, figs. 290-300. Syncor\ne reticulata, ALLMAN, 1871, Monog. Tubul. Hydroids, p. 283. Syndictvon reticulatum, HAECKF.L, 1879, Syst. der Medusen, p. 21. ( ?) Syndictyon raiculalum, MAAS, 1893, Ergeb. der Plankton-Expedition, Bd. 2, K. c., p. 67. (tySarsia turrreula, MrCRADV, 1857, Gymn. Charleston Harbor, p. 36, plate 8, figs. 6-8. S\ncor\ne reticulata, HARGITT, 1904, Bulletin Bureau of Fisheries U. S., vol. 24, p. 30. Sarsia reliculata, HARTLAUB, 1907, Nordisches Plankton, Nr. 12, p. 45, figs. 41-43. (?) Sarsia pulchella, AI.I.MAN, 1871, see Hartlaub, 1907, Nordisches Plankton, Nr. 12, p. 34, fig. 27 (abnormal twin medusa:, fig. on p. 109). — SPAGNOLINI, 1876, Catalogo Acalefi Mediterranco, p. 18, tav. 2, figs. i. 2. Adult medusa. — Bell ellipsoidal in shape, being about 4 mm. in height and 3.5 mm. in diameter. No apical projection. Gelatinous substance quite thick at the aboral pole, but thin at the bell-margin. There are 4 long, highly contractile tentacles, I at the base of each radial-canal. Surfaces of these tentacles covered with prominent nematocyst capsules. Basal bulbs of tentacles well developed and each one contains an ectodermal ocellus upon its outer side. Velum wide and thin. There are 4 straight, narrow radial-canals, and a slender circular vessel. Manubrium short and club-shaped, and does not extend far beyond the velar opening. Mouth a simple, round opening. Genital products developed along the greater part of the length of the manubrium. The entoderm of the manubrium and tentacle-bulbs is brick-red. Hydroid and young medusa. — Smaller than Coryne mirnliilis, being not more than 3 mm. in height. Stems slender and hardly ever branch, excepting in old specimens, which some- times give rise to a single branch near the base of the stem. Polypites large and club-shaped, and having several whorls composed of 8 to 10 short tentacles. The medusae develop among the tentacles near the proximal base of the polypite. When set free the young medusa is remarkably large, being about 1.5 mm. in diameter. The bell is covered \\irh reticulated clusters of nematocyst-cells (plate 4, figs. 3, 4) which are especially numerous near the bell- margin above the circular canal. Some of these nematocyst-cells are large and round, while others are narrow and long. The tentacles are thickly covered with helically arranged clusters of nematocyst-cells. These cells (plate 4, fig. 4) are ellipsoidal in shape and are mounted upon a short basal pedicel. Each cell gives rise to a long, sharp-pointed, sensitive hair. The nematocyst thread lies coiled in a helix within the cavity of the cell. As the medusa becomes mature the reticulated nematocysts disappear from the surface of the exumbrella and the nematocysts upon the tentacles become less prominent. This medusa is found upon the Ne\\ England coast from April until June. It is distinguished from Sm-sm mirabilis only by its nematocyst-covered tentacles and exumbrella and its small hydroid. It appears also to be constantly brick-red, while 5. mirabilis is highly variable in color. It is often impossible to distinguish mature medusae of S. reticulata from those of .V. mirabilis. It is possible that the S. pulchella of Spagnolini, 1876, from Naples, Italy, is identical with .S'. r, n, uLita. Sarsia eximia Boehm. Coryne eximia, ALLMAN, 1859, Annals and Mag. Nat. Hist., ser. 3, vol. 4, p. 141; 1864, Ibid., vol. 13, p. 357. Syncoryne eximia, HINCKS, 1868, Hist. British Hydroid Zooph., p. co, plate 9, fig. 2. — ALLMAN, 1871, Monog. Tubul. Hydroids, p. 282, plate 5. Sarsia eximia, BOEHM, 1878, Jena. Zeitschrift fur Naturw., Bd. 12, p. 191, taf. 6, figs. 7-26; taf. 7, figs. 1-6. — (In part), HAEC- KEL, 1879, Syst. der Mcdusen, p. 17. — HARTLAIPII, 1894, \Vissen. Meercsuntcrsuch. Komini^. Mo-rc. Kid, lldi;ii]and, Ser. 2, Bd. i, p. 187. Svncorvne eximia (hvdroid). NUTTINC;, 1901, Proc. Washington Acail. Sa., vol. 3, p. 166, plate 14, figs. 3, 4. Sarsia eximia, BROWNE, 1905, Proc. Roy. Soc. Edinburgh, vol. 21;, p. 756 (hydroid and medusa). — BROCB, 1905, Bergcns Museums Aarbog, No. 11, p. 4. Sarsia tximia=S. bretonica, HARTLAUB, 1907, Nordisches Plankton, Nr. 12, p. 8, figs, i, 2a, 26 (full list of recent literature). Syncorync eximia, BROWNE, 1907, Journal Marine Biol. Association, vol. 8, p. 37 (growth of the hydroid). This form is found off the coasts of Great Britain, Helgoland, Shetland Islands, Norway, and Juneau, Alaska (Nutting). For details of the medusa, see tabular description of the medusas of Sarsia. The hydroid is about 30 mm. high, forming a bush-like cluster of profusely branched stems; the branches are short and simple and arise very irregularly from the main stems, and are usually faintly ringed at their points of origin. The main stem is usually unringed, 58 MEDUSJE OF THE WORLD. except at its base, and is quite smooth. The polypites are very elongate, spindle-shaped, and have about 1 6 to 24 short, knobbed tentacles arranged in 4 to 6 somewhat irregular verticils. The medusa-buds arise singly upon short peduncles near the bases of the tentacles of the lower verticils. The entoderm is red to reddish-brown and the stems are yellow. Browne found that confinement in an aquarium under somewhat unnatural conditions caused the hydroid to grow rapidly and to form stolons, these being developed from branches which touched the glass sides of the aquarium. He also discovered that the medusa becomes mature in from J to 10 days after being set free from the hydroid. Later, in 1907, Browne found that one of these hydroids placed in a glass tube with a constant current of water passing through it grew in length from 14 to 77 mm. in the course of 9 days, and developed branches having a total length of 500 mm. The hydroid was fed upon copepods. Sarsia radiata von Lendenfeld. Sarsia radiata, VON LENDENFELD, 1884, Zool. Anzeiger, Jahrg. 7, p. 584; 1884, Proc. Linnean Soc. New South Wales, vol. 9, pp. 583, 635; plate 20, figs. 31, 32; plate 30, figs. 1-4. Medusa. — Bell semiovate, slightly higher than broad, 3 mm. high, 2.5 mm. wide. 4 ten- tacles, each about 1.5 times as long as bell-height, and with large bulbs about half as wide as the manubrium. Ocelli (?) Velum wide. 4 straight radial-canals. Manubrium cylindrical, half as long as the bell-height. The gonad incases the sides of the manubrium from the inner apex of the bell-cavity to near the mouth. No medusa- buds. Entoderm of manubrium and tentacle- bulbs deep brown. Other parts colorless. H \droid. — The hydrocauli arise from a creeping hydrorhiza which anastomoses in a very open network. The perisarc terminates with an oblique elliptical margin at the base of each hydranth, and the hydranth is provided with a muscle at this point which enables it to bend downward and "shut up" as if it were the blade of a penknife. The hydranths are spindle- shaped, narrow, and elongate; and are, includ- ing their hydrocauli, 3 to 5 mm. high. They have 6 to 8 verticils, each of 4 tentacles, situated in 4 meridional lines, 90° apart. These tentacles are all knobbed at their ends. The hydranths which produce medusae are shorter than the sterile polypites. The medusae bud out from the lower half of the polypite between the tentacles. The entoderm is intensely brown in color, and the perisarc is bright brownish-yellow. Other parts colorless. Found on the coast of New South Wales, Australia. The medusae are produced in April and May. Sarsia conica. Codonium eonicum, HAECKEI., 1880, Syst. der Medusen, p. 634. Bell barrel-shaped with conical apex one-third as long as the sides of bell. 12 mm. high, 4 mm. wide. 4 tentacles longer than bell-height, and with small oval basal bulbs. The manubrium is half as long as the depth of the bell-cavity. The stomach is subspherical and swollen by the encircling gonad. The mouth is at the end of a short, cylindrical throat-tube which is free of gonads. Color ( ?) There is a long axial canal above the stomach. Indian Ocean. Briefly described, without figures, by Haeckel. FIG. 21. — Sarsia eximia, from life, by the author. Mouse- hole, Cornwall, England, Nov. 14, 1907. A\THi>MKI>rs.K--SAi;-.I \. .V.I Sarsia rosaria Haeckel. Coryne rosaria, AGASSIZ, L., 1862, Cent. Xat. Hist. U. S., vol. 4, p. 340. — A- \ i/. \.. i Sf>;, Virrh Arm-r. Aca!., p. 176, fig 289. Sarsia rosaria, HAECKEL, 1879, Syst. Jer Mi .i'i CDj p. 18. Santa rosaria= Syncoryne rosaria, FEWKES, iSSij. Am. r. Vituralist, vol. 23, p. 597, plate 25, fig. 7; tcit-figs. 8, 9 (hydroid?). Syncoryne occidentals, FEWKKS, 1889, Bull. Essei Inst., Salem, vol. 21, No. 7, p. 99, plate 3, figs. 2, 3. ( ?) Syn diclyon angulatum, Mt RUAI H and SIIK^RV.R, 1903, Proc. Zoo]. Soc. London, vol. 2, p. 168. Codonium apiculum, MURBACH and SHEARER, 190}, Proc. Zool. Soc. London, vol. 2, p. 165, plate 17, fig. i; plate 22, figs. 4, 5; 1902, Annals and Ma^. Nat. Hist., scr. 7, vol. 9, p. 72. Sarsia apicula+S. rosaria, HARTLAI'B, 1907, Nordischcs Plankton, Nr. 12, pp. 17, 50, figs. 9, 45. Bell 15 to 30 mm. high, 10 to 15 mm. wide, with fairly thick walls and small apical projection. 4 equally developed, radially placed tentacles 1 .5 to 2 times as long as bell-height. The basal bulbs of these tentacles are large and are flanked on either side by a large nemato- cyst-pad. Each tentacle-bulb bears an abaxial ocellus. There are 4 slender, straight-edged radial-canals and a narrow ring-canal. The velum is well developed. Manubrium short and spindle-shaped, and mouth about at the level of the velar opening. There is a short axial canal above the stomach. The gonad encircles the stomach, leaving both ends tree. N<> medusa-buds. The colors are quite variable as in other species ot Sarsia. The tentacle- bulbs range from yellow through red to brownish-red, and the stomach is yellow, pink, or reddish-violet to purple. This is the most abundant Sarsia along the Pacific coast of the United States. It occurs in great swarms in San Francisco Harbor in spring; and in Victoria Harbor, Puget Sound, in July. The hydroid is Syncoryne rosaria found by A. Agassiz and Fewkes in shallow water attached to piles of wharves. Each tentacle terminates in a knob, and the hydroid is a true Syncoryne. Sarsia minima von Lendenfeld. Sarsia minima, VON LENDENFELD, 1884, Proc. Linnean Soc. New South Wales, vol. 9, pp. 584, 915, plate 21, figs. 34, 35. Bell of medusa 3 mm. high and 2.5 mm. wide with "a long manubnum like the northern Sarsia;." It is therefore readily distinguished from Sarsia radiata, which has a short manu- brium. S. minima has a spindle-shaped, nearly cylindrical manubnum which extends tor about half its length beyond the velar opening. The 4 marginal tentacles are somewhat longer than the bell-height and are covered with rings of nematocysts. The entoderm ot the stomach is pale brown, other parts colorless. Hydroid. — The stems are 2 to 3 mm. high and arise from a creeping, slightly branched, non-anastomosing hydrorhiza. The perisarc which invests the hydrorhiza and hydrocauli is irregularly annulated or wavy throughout, and terminates at the bases of the hydranths in a transverse margin. The hydranths are slender, spindle-shaped, 0.6 to 0.8 mm. long, and with 8 to 12 irregularly scattered tentacles, all of which are knobbed at their ends. When they produce buds they become stouter, and are so thickly covered by the budding medusae "that nothing of their bodies remains visible." The perisarc is reddish-brown. This hydroid is found at Port Jackson, New South Wales, Australia, overgrowing Obclla geniculata, on buoys and submerged ropes. The medusae are produced in April and May. Von Lendenfeld did not obtain any mature medusae. Sarsia brachygaster Grbnberg. Sarsia brachygaster, GRONBERO, 1898, Zoolog. Jahrb., Abth. Syst., Bd. 1 1, p. 459, taf. 27, figs. 3, 4. — HARTLAI n, 1907, N'or- disches Plankton, Nr. 12, p. n, fig. 3. Bell 15 to 18 mm. high and 8 to 10 mm. wide and three-fourths-egg-shaped, the greatest breadth being above the middle. 4 radially situated tentacles, each being about twice as long as the bell-height. Basal bulbs of these tentacles well developed, and a single MI\ small ocellus upon the outer side of each bulb. Manubrium cylindrical, and two-thirds as long as height of bell-cavity. Mouth situated at extremity of a shoit cylindrical neck. The gonad is tubular and surrounds the stomach. No medusa-buds. The manubrium, gonads, tentacle-bulbs, and tentacles are orange-red. The ocelli are black. 60 MEDUS.E OF THE WORLD. Gronberg found this species at Spitzbergen in summer, and he also identified it among a collection of medusae from Jakobshavn, Greenland, where it appears to be rarer than at Spitzbergen. Sarsia angulata Hartlaub. Plate 5, fig. i; plate 6, fig. 3. Syndictyon angulatum, MAYER, 1900, Bull. Mus. Comp. Zool. at Harvard College., vol. 37, p. 5, figs. 6-8, plate 3; 1904, Memoirs Nat. Sci. Brooklyn Institute Museum, vol. I, No. I, p. 7, plate I, fig. 6. N on Syriilict\on tiHgtihitum, MURBACH and SHEARER, 1903, Proc. Zool. Soc. London, vol. 2, p. 168. Sarsia angulata, HARTLAUB, 1907, Nordisches Plankton, Nr. 12, p. 16. Bell i mm. high; half-egg-shaped, with moderately thick walls. Becomes almost square in cross-section when contracted. There are 4 slender tentacles with fairly thick spindle- shaped ends. These tentacles are each about as long as bell-height and their distal halves are tapering and are armed with nematocysts. The basal bulbs of the tentacles are not very large, and each one bears an ocellus formed by a cup-like invagmation of ectodermal cells. The velum is large, and the radial-canals and circular vessel are of fine caliber. The manubrium is spindle-shaped with a narrow tubular o?sophagus and without an aboral projection. It is about two-thirds as long as the height of the bell-cavity. The gonad encircles it, extending from the base to near the mouth, leaving the throat-tube free. The entoderm of the tentacle- bulbs and manubrium is robin-egg blue, while the ocelli are deep-brown, almost black. All other parts are hyaline. This medusa is abundant in the Tongue of the Ocean, Bahama Islands, in June and July, and was found at Turks Island in January. It is rare at Tortugas, Florida. Sarsia gracilis Browne. Sarsia gracilis, BROWNE, 1902, Annals Mag. Nat. Hist., ser. 7, vol. 9, p. 275. (? ?) S\ncoryne sarsii (hydroid), HARTLAUB, 1905, Zoolog. Jahrbiichern, Suppl. 6, p. 525, fig. F. Bell 5 mm. high, 3 mm. wide; cylindrical, with moderately thick walls and quadrangular margin. 4 tentacles, about as long as the bell-height, and end- ing each in a large knob containing nematocysts. An ocellus on the basal bulb of each tentacle. Manu- brium about two-thirds as long as the depth of the umbrella cavity. Color ( ?) Gonads ( ?) Found at Stanley Harbor, Falkland Islands, by Vallentin, and briefly described without figures by Browne. The hydroid, Syncoryne sarsn, described by Hartlaub from southern Terra del Fuego, may be the stock ot this medusa. The medusa may be a young Slabberia ( ?) Sarsia princeps Haeckel. Codonium princeps, HAECKEL, 1879, Syst.derMedusen,p.l3,taf.l,figs. 1,2. Sarsia princtps, HAECKEL, 1879, Ibid., p. 655. — LINKO, 1905, Zool. An- zeiger, Bd. 28, p. 212. — BROWNE, i9O3,Bergens Museums Aarbog, No. 4, p. 8, plate i, fig. i; plate 3, fig. 4. — HARTLAUB, 1907, Nor- disches Plankton, Nr. 12, p. 47, fig. 44. Codonium princeps, LEVINSEN, 1893, Vid. Meddel. Nat. For. Kjobenhavn (5), Bd. 4, p. 143. — GRONBERG, 1898, Zoolog. Jahrb., Abth. Syst., Bd. n, p. 458, taf. zj, figs, i, 2. Bell thin-walled and conical, about 25 to 40 mm. high, and 15 mm. wide. There is a short, conical, apical projection. There are 4 tentacles with long conical basal bulbs. The shafts of these tentacles 1-iG. 22. — barsia princeps, alter Hartlaub, in Nordisches Plankton. are very contractile, three or four times as long as PLATE 6. Figs, i and i'. Hydroid of Ectopleura Jumortieri. Dredged from a depth of 5 fathoms in Newport Harbor, Rhode Island, August, 1896. Figure I, enlarged view; figure i', natural size. Fig. 2. Medusa of Ectopleura dumortteri. Agassiz Laboratory, Newport, Rhode Island, July, 1892. Fig. 3. Sarsia angulata. Turks Islands, Bahamas, January 2O, 1893. Fig. 4. Protiara formosa, male. Nassau Harbor, Bahamas, June, 1903. Fig. 5. Protiara formosa, female. Tortugas, Florida, June IO, 1897. Fig. 6. Protiara formosa, young medusa. Turks Islands, Bahamas, January 20, 1893. Fig. 7. Zanclea gemmosa. Manubrium of the medusa shown in figure 5, plate 7. Drawn from life, by the author. PLATE 6 ANTHOMEDUS.fi — SARSIA. 61 the bell-height, and covered with alternately arranged, wart-like clusters of nematocysts. A small ocellus is situated on the outer surface of each tentacle-bulb near the bell-margin. There are also 2 globular swellings, one on either side of each tentacle-bulb adjacent to bell-margin. The velum is narrow. There are 4 narrow, ragged-edged radial-canals and a slender circular canal. A short axial canal extends upward from the stomach-cavity into the gelatinous substance of the apical projection of the bell. The manubrium is long and cylindrical, and extends for about one-third of its length beyond the velar opening. The mouth is a simple opening without prominent lips. A single, short, tubular gonad is developed upon the sides of the manubrium. The manubrium, gonads, and tentacle-bulbs are purple. The ocelli are black. This species is found off the coasts of Greenland and Spitzbergen, where it appears to be common. Gronberg, 1898, found it to be abundant at Spitzbergen, and Linko, 1905, found it to be common in Barents Sea, north of Lapland, Russia. It is the largest known Sarsia. Gronberg's description is based upon the study of living medusae. Hartlaub also gives an excellent figure of the medusa, which we reproduce. FIG. 23. — Sarsia prolifera, from life, by the author. Mouse- hole, Cornwall, England, Nov. 8, 1907. FIG. 24. — Sarsia codonophora, after Haeckcl, 1879. Sarsia prolifera Forbes. Sarsia proliftra, FORBES, 1848, British Naked-eyed Mi-ilus.r, p. 59, plate 7, fig. 3. — BUSCH, 1851, Beobacht. wirbeilos. Seeth., p. i, taf. i, figs. 1-6. — BEDOT, 1905, Revue Suisse de Zool., tome 13, p. 147 (all literature to 1850). — HARTLAUB, 1907, Nordisches Plankton, Nr. 12, p. 15, figs. 7, 8. Syncorync prolifera, ALLMAN, 1871, Monog. Tubularian Hydroids, p. 83, fig. 38. Codonium codonophorum+ Sarsia prolifer, HAECKEL, 1879, Syst. der Medusen, pp. 14, 18, taf. I, fig. 3. Sarsia codonophora, HAECKEL, 1880, Ibid., p. 655. 62 MEDUS.'E OF THE WORLD. In 1848 Forbes described this medusa from Penzance Bay, southern England, where it was abundant in August, 1846, and in 1879, and where I found it in November, 1907. Haeckel describes that which may prove to be the same species from the Mediterranean. The points of difference between the two medusae will be brought out in the following description. The bell is bell-shaped; in Forbes's medusa (fig. 23) 3 mm. wide and 4 high; in Haeckel's, (fig. 24), 8 mm. wide and 8 mm. high. Forbes's medusa lacks an apical projection, while Haeckel's has a short, conical, pointed apex. Also, in Forbes's medusa there was no axial canal above the stomach while in Haeckel's there was a narrow, axial vessel. Moreover, in Haeckel's medusa the margin of the bell flares outward, while in Forbes's specimen this is not the case. It is well known to students of the Anthomedusae that apical projections and axial canals are exceedingly variable, and may be absent or present in individuals of the same species. The outward flaring of the bell may be brought about through contraction. Haeckel's medusa appears to be merely a large, highly-colored specimen of S. prohfera Forbes. The 4 marginal tentacles are I to 3 times as long as the bell-height. Their basal bulbs are large and tapering and about as wide as they are long. The tentacles taper gradually from base to shaft and are hollow. Clusters of I to 3 medusa-buds at a time are developed upon the tentacle-bulbs immediately below the bell-margin. When set free these medusas are already producing another asexual generation of medusas upon their tentacle-bulbs. The 4 radial-canals and ring-canal are straight and very narrow. The manubnum is spindle- shaped and nearly as long as the bell-height in Haeckel's, but not half so long in Forbes's medusa. The mouth is at the end of a narrow neck and is a simple, round opening. The stomach is encircled by the gonad, leaving the base and the throat-tube free. Entoderm of tentacles and manubnum yellow to orange or sage-green. Each tentacle- bulb bears a prominent ectodermal brown-colored ocellus. If it be true that Forbes's and Haeckel's forms are identical the medusa must range from southern England to the Mediterranean. It appears to be rare and its hydroid is unknown. Allman, 1871 (p. 83, fig. 38). gives a figure of a medusa which closely resembles Forbes's Sarsta prohjera. I found numerous specimens of this medusa off Mousehole, Mounts Bay, Cornwall, England, early in November, 1907. They accord well with the descriptions of Forbes and of Busch. The entoderm of the manubrium and tentacle-bulbs was sage-green; the tips of the tentacles light reddish-brown, and occasionally there was some reddish-brown pigment in the central entoderm of the stomach. The gonad encircled the stomach, leaving both ends of the manubrium free. Sarsia gemmifera Forbes. Sarsia gemmifera, FORBES, 1848, British Naked-eyed Medusae, p. 57, plate 7, fig. 2. — CHUN, 1895, Bibliotheca Zoologica, Heft 19, pp. 4, 7, taf. I, figs. 5, 6 (law of development of medusa-buds). — BROWNE, 1905, Proc. Roy. Soc. Edinburgh, vol. 25, p. 757. — BROCH, 1905, Bergens Museums Aarbog, No. 1 1, p. 4. Codonium gemrniferum+ Sarsia sipfionophora, HAECKEL, 1879, Syst. der Metlusen, pp. 15, 20, taf. I, fig. 4. Codonium gcmmifcrum, BEDOT, 1905, Revue Suisse de Zool., tome 13, p. 132 (citation of literature to 1850). Purena gemrtiifera, HARTLAUB, 1907, Nordisches Plankton, Nr. 12, p. 58, figs. 54-58. This medusa is tound off the Atlantic coasts ot Europe from Norway southward. Haeckel's Sarsia "siphonopliora" from the Canary Islands is probably another name for the same species. When young the medusa produces medusa-buds upon its manubrium. These arise in a spiral line, one following the other, down the sides of the manubrium. The oldest of the primary medusa-buds is nearest the base (uppermost) and the youngest nearest the mouth of the manubrium. These primary medusa-buds are attached to the sides of the manubnum by short pedicels, and secondary and tertiary medusa-buds arise from the sides of these pedicels. Thus when the oldest (uppermost) original medusa-bud is set free, the secondary bud upon its pedicel remains attached to the manubrium and continues to develop, and when it in turn is set free the tertiary bud completes its development; this process takes place with each and every one of the series of buds. ANTHOMEDUS.E — SARSIA. 63 This successive freeing of the three series of buds produces various appearances at different periods of time, and in this manner we may explain the condition observed by Haeckel, 1879, in Sarsia " siphonop/iora," where the buds appeared in two series, the oldest and largest of the upper series being at about the middle ot the manubnum, while the oldest ot the lower series was near the base of the stomach. Forbes, 1848 ( plate 7, fig. 2 e), shows an intermediate stage in the budding process, and an early stage is shown by Chun, 1895 (fig. 25 A). The law of succession in development of the medusa-buds is clearly demonstrated by Chun. Both ectoderm and entoderm of the manubrium take an equal share in the formation of the budding medusae. For details of the character of the medusa, see tabular description of the medusae of Sarsia. Haeckel failed to observe the sec- ondary and tertiary medusa-buds upon the pedicels of the budding medusae in his Sarsia siplionophora, but this is probably due to an oversight, tor in all other respects his medusa appears to be identical with S. gemmiftra P'orbes. The gonad develops at the distal end of the manubrium after the budding process has ceased. Possibly there may be 2 or more ring-like gonads ? (See Hartlaub, 1907.) If this be the case the medusa may be identical with Dipuretia fertilis Metschnikoff, 1871. Sarsia hargitti. Corynt producta, HARGITT, 1902, American Natural- ist, vol. 36, p. 550, fig. 3. Syncorynf produtla, HAROITT, 1904, Bulletin Bureau of Fisheries U. S., vol. 24, p. 30, plate I, fig. I. A medusa called Sarsia producta is produced by budding from the hydroid of StauriJia producta Wright; and as this name takes precedence over that of Hargitt's medusa, it is necessary to rename the American species. Bell i .5 mm. high, and I mm. wide. Apex dome-like and rounded, and sides slightly compressed. Bell-cavity only about half as deep as the height of the bell. There are 4 long, equally devel- oped tentacles with large basal bulbs, each with a large, ectodermal ocellus. Velum well developed. The 4 radial- canals are narrow, straight, and smooth- edged. The manubrium projects far beyond the veJar opening, but is cap- able of great contraction. Its terminal part is bulb-like, while the basal portion is spindle-shaped and bears a whorl of medusi- 1'orin gonads. The stomach gives rise to a blunt, dome-shaped aboral projection. The mouth is a simple, round opening. The basal part of the manubrium is orange, and its free end blue-green. The tentacle-bulbs are orange, edged with delicate green. The ocelli are black. A single specimen was found by Hargitt at Woods Hole, Massachusetts, on August FIG. 25. — Sariia gcmmifera, showing law of building. After Chun, in Bibliotheca Zoologica, Heft 19, taf. I, 1895. A, early; B, later stages of the process of budding. 64 MEDUSAE OF THE WORLD. 10, 1901. It is distinguished from all other American species of Sarsia by its medusiform gonads borne upon the manubrium (text-fig. 26). It is not known whether medusae are set free from the manubrium of the parent medusa. Sarsia flammea Hartlaub. Sarsia eximia (in part), HAECKEL, 1879, Syst. der Medusen, p. 17. Sarsia fammea, LINKO, 1905, Zool. Anzeiger, Bd. 28, p. 212. — HARTLAUB, 1907, Nordisches Plankton, Nr. 12, p. 12, figs. 4-6. (literature); 1903, Zool. Centralblatt, p. 22. Bell high oval, 12 mm. high, 7 mm. wide, walls quite uniform and of moderate thickness. 4 tentacles, with well-developed, simple basal bulbs without ocelli. Tentacle tips slightly enlarged, club-like. Nematocysts over distal halves of tentacles arranged in prominent, broken rings. 4 slender, straight radial-canals. Manubrium thick, conical, spindle-shaped; only two-thirds as long as the depth of the bell-cavity. No axial-canal above the stomach. Gonad ring-like, encircling the manubrium from base to near the mouth. Stomach and tentacle- bulbs light fiery-red or orange. From the Arctic Ocean. FIG. 26. — Sarsia hargitii, after Hargitt, in Bull. TJ. S. Bureau of Fisheries. FIG. 27. — Sarsia flammea, after Hartlaub, in Nordisches Plankton. Showing arrangement of nemato- cyst clusters on tentacles. Separated from Sarsia eximia and S. brachygaster by its lack of ocelli, and from S. brachygaster also by its smaller size. The best description is that of Hartlaub, 1907. Hydroid unknown. It is possible that this may be the medusa of the parasitic hydroid called Hydnchthys mirus Fewkes. Genus SARSIA, Subgenus STAURIDIOSARSIA nov. subgen. Stauridium, HARTLAUB, 1895, Zeit. fiir wissen. Zool., Bd. 61, p. 142; 1907, Nordisches Plankton, Nr. 12, p. 52. CHARACTERS OF THE SUBGENUS. Medusa similar to Sarsia, but the hydroid is Stauridia, not Syncoryne. The name Stauridia should not be applied to these medusae, for it was first used by Dujardin, 1843, to describe a hydroid which gives rise to a Cladonema medusa. It may be well to apply the new generic name Stauridiosarsia to hydroids which resemble Stauridia, but produce Sarsia-\\ke medusae. ANTHOMKDUS.E — SARSIA. 65 Sarsia (Stauridiosarsia) producta. A^on Stauridir, DUJARDIN, 1843, Ann. Sci. Xaturelles, scr. 2, torn. 20, p. 370. Stauridia producta, WRIGHT, 1858, Edinburgh New Philos. Journ., ser. 2, p. 283, plate 7, figs. 6-8. Stauridium productum, HINCKS, 1868, British Hydroid Zoophytes, p. 68, plate 12, figs, i, I a. — HARTLAUB, 1895, Zcit. fur wissen. Zool., Bd. 61, p. 142, taf. 7, figs. 1-19; taf. 8, figs. 1-4; taf. 9, figs. I, 2, 6; 1907, Nordisches Plankton, Mr. 12, p. 53, figs. 47-50. The medusa is a Sarsia, but the hydroid is similar to Stauridia, and differs from Syn- corync, the hydroid of Sarsia, in that there is a basal circlet of simple, knobless tentacles; whereas all of the tentacles of Syncoryne terminate in knobs. The tentacles of Stauridia 28. FIG. 28. — Sarsia producta, after Hartlaub, in Nnrdisches Plankt»n. FIG. 29. — Medusa; of "Sarsia producla," natural size; after Hartlaub, in \ordischt-s Plankton. FIG. 30. — "Stauridium productum," after Hincks, in British Hydroid Zoophyte-;. Hydroid and young medusa. are of two sorts — the simple, short, stiff, tapering, knobless basal circlet, and above them several circlets of knobbed tentacles which arise from the sides ot the hydranth. In Syncoryne, on the other hand, we find only knobbed tentacles. Thus two distinct genera of hydroids produce one and the same genus of medusa. Moreover, Dujardin, 1843, discovered that the hydroid which he called "StauriJie" produces the medusa Cladonema rnJititutu. As the name Stauridia is preoccupied by Dujardin to designate the hydroid of Cladonema it can not be applied to the medusa of Stauridia producta. I therefore call the medusa of Stauridia producta by the name Sarsia producta, thus indicating its relationships when in the reproductive stage. The medusa Sarsia producta, which is produced by the hydroid Stauridia producta, may be described as follows: Bell 10 mm. high, 7 mm. wide, three-fourths-egg-shaped, with thick, gelatinous walls. 4 equally developed, radially placed tentacles; 1.5 times as long as the bell-height. Tentacle- 66 MEDUSA OF THE WORLD. bulbs large, each with an abaxial, ectodermal ocellus. Manubrium cylindrical, with about one-third of its length extending beyond the velar opening. A short, conical axial canal above the stomach. Gonad extends from the base to the distal end of the manubnum. No medusa- buds. Stomach brownish, gonads yellowish-white, tentacle-bulbs and axial canal red. Helgoland and British coasts. The hydroid has a thin-branching hydrorhiza, from which a number of club-shaped hydranths arise singly. These hydranths are each about 2 mm. long, with a proximal circlet of 4 to 6 short knobless tentacles, and above 2 or 3 more or less irregular circlets of large knobbed tentacles, usually with 4 tentacles in each circlet. The medusa-buds are produced from the sides of the hydranth above the basal circlet of tentacles. The hydranths are red. The hydroid and medusa are described in detail by Hartlaub, 1895. The English and Helgoland forms differ considerably and they may be regarded as varieties one of the other (see Hartlaub, 1895, p. 157). The hydrorhiza of the English form anastomoses, while that of the Helgoland hydroid branches sparingly and does not anasto- mose. In the English form the knobbed tentacles are in whorls of 4 each, whereas in the Helgoland hydroid there areotten 5, occasionally 6, tentacles in each whorl. In the English form the medusae are said to arise from the bases of the ten- tacles, while in the Helgoland form they arise from the sides of the polypite between the knobless basal circlet and the lowest circlet of knobbed tentacles. Finally the Hel- goland medusa has a largeaxial canal above the stomach, and this appears to be absent in the English medusa. Genus HYDRICHTHYS Fewkes, 1888. H\drichthys, FEWKES, 1888, Bull. Mus. Comp. Zool. at Harvard Coll., vol. 13, p. 224; 1888, Annals and Mag. Nat. Hist., ser. 6, vol. i, p. 364. — HARGITT, 1904, Bull. U. S. Bureau of Fisheries, vol. 24, p. 32. ( ?) Plotocnide, HARTLAUB, 1907, Nordisches Plank- ton, Nr. 12, p. 68. GENERIC CHARACTERS. The medusa resembles Sarsia, but is without ocelli upon the ten- tacle-bulbs. The mature medusa has not been determined. The hydroid is firmly attached to the side of a fish (Sertola zonata), and is probably parasitic, and degenerate in many respects. All of our knowledge of this remarkable form is derived from Fewkes, 1888. It differs widely from all other known forms of Tubulanan hydroids. In default of knowledge of the mature medusa we must remain in doubt concerning its true place in our classification. It is possible that Sarsia flamrnea Hartlaub may be the mature stage of this medusa. \ FIG. 31. — Young medusas of Hydrichthys rnirus, from Fewkes, in Bull. Museum Comp. Zool. at Harvard College. ANTHdMKDUS.E — HYDRICHTHYS. 67 Hydrichthys mirus Fewkes. Hydrichthys mirus, FEWKES, 1888, Bull. Mus. Comp. Zool. at Harvard Coll., vol. 13, No. 7, pp. 124-232, plates 4, 5, 7 figs.; 1888, Ann. and Mag. Nat. Hist., ser. 6, vol. i, p. 364; 1888, Proc. Boston Soc. Nat. Hist., vol. 23, p. 391. — HARGITT, 1904, Bulletin Bureau of Fisheries U. S., vol. 24, p. 32. Medusa. — The adult medusa is undetermined, but may possibly be Sarsia flammea. The most advanced medusae reared by Fewkes had the following characters: Bell rounded, without apical projection, and in form somewhat fuller than a hemisphere. Size ( ?) Outer surface of bell besprinkled with nematocysts. Bell-walls of moderate thickness, becoming thinner near the margin. There are 4 long, equally developed, radially situated tentacles, with long, tapering basal bulbs which lack ocelli. The 4 radial-canals are broad and straight and there is a simple, narrow, circular vessel. Manubrium cylindrical and about half as long as the depth of the bell-cavity. Mouth surrounded by 4 simple lips ( :). The entoderm of the manubrium is yellow and orange, while that of the tentacle-bulbs is orange. Other parts of the medusa are colorless. Fin. 32. — Hydroid of ffyjriehthyi mirus, from Fewkes, in Bull, \fuseurn Comp. Zool. at Harvard College. Fish bearing hydroid, and a magnified part of hydroid itself. I'oinig medusa. — When first detached from the hydroid the medusa has but two diametri- cally opposite tentacles, and is more active in its movements than it is when it acquires four tentacles. This may, however, have been due to the injurious effects of confinement. Hydroid. — The hydroid was found by Fewkes firmly attached to the side of a small fish, Seriola zonata. The hydroid colony arises from a basal network of tubes which forms a plate-like hydrorhiza embedded under the scales of the side of the fish, upon which it is probably a parasite. This basal network gives rise to tubular gonosomes and also to filiform, flask- shaped bodies, which recall the spiral zooids of Hydractinia, excepting that they appear to have a terminal mouth-opening. The medusa-bearing gonosomes are conical and gradually taper from base to summit, where there may be a terminal opening. Irregularly distributed side'branches arise from the main axis of the gonosome, and most of these give rise to medusa-buds. These side branches are usually simple, although occasionally they branch. They are hollow and in communi- cation with the entodermal cavity of the main stem. Clusters of medusa-buds in various stages of development arise from the ends of the branches. When set free these medusae have but 2 tentacles, but later 2 more tentacles develop. 68 MEDUSA OF THE WORLD. All parts of the hydroid stock are highly contractile and the gonosomes and zooids are without chitinous sheaths. The hydroid is colorless, but the medusa-buds are reddish and orange in color. The terminal parts of the flask-shaped zooids are also pigmented with reddish-orange. A single stock of this hydroid was found by Fewkes in Narragansett Bay, Rhode Island, attached to a fish, Seriola zonata, in August, 1887. The fish was swimming near the surface and was apparently but little injured by the presence of the parasite. It is interesting to observe that Alcock, 1892 (Annals and Mag. Nat. Hist., ser. 6, vol. 10, p. 207, I fig.), has discovered a hydroid of the genus Stylactis which is commensal upon a fish, Minous inermis. This hydroid, however, produces no medusae. Genus EUCODONIUM Hartlaub. Eucodonium, HARTLAUB, 1907, Nordisches Plankton, Nr. 12, p. 71. The type species is Eucodonium brownei Hartlaub = Dipurena sp. Browne, from the British Coast. GENERIC CHARACTERS. Codonidae with 4 equally developed, radially placed tentacles, each of which terminates in a distal knob. Stomach mounted upon a gelatinous peduncle. Hydroid unknown. This genus is distinguished from Sarsia and Slabberia by the gelatinous peduncle upon which the stomach is placed. It is distinguished from Dysmorphosa by the terminal knobs of its tentacles and by its ring-like gonad. Eucodonium brownei Hartlaub. Dipurena sp., BROWNE, 1896, Proc. Zool. Soc. London, p. 473, plate 16, fig. 2. Eucodonium brawnei, HARTLAUB, 1907, Nordisches Plankton, Nr. 12, p. 71, fig. 67. Bell pyriform, thin-walled, I mm. wide. 4 radially placed, slender tentacles with small basal bulbs. Ten- tacles twice as long as the bell-height and with scattered nematocysts along their lengths, and each with a large, swollen, nematocyst-beanng knob at outer end of tentacle. No ocelli. Velum wide. 4 straight, narrow radial-canals. Stomach short, mounted upon a conical, gelatinous from Europe, after Hincks in Brit- peduncle. Mouth a simple, round opening at about the level of the velum. Medusa-buds arise from the sides of the stomach. The tentacle-bulbs are blackish, stomach and terminal knobs of the ten- tacles, dull dark-brown. Found at Plymouth, England, in September. Gonads( ?) This is a young medusa, but we can not refer it to any known mature form. Genus ECTOPLEURA L. Agassiz, 1862 (sens, amend.). Tubularia dumortierl, VAN BENEDEN, 1844, Mem. Acad. Belgique, tome 17, p. 50, plate 2. Eclopleura, AGASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 343. — AGASSIZ, A., 1865, North Amer. Acal., p. 191. — HAZCKEL, 1879, Syst. der Medusen, p. 21. — FEWKES, 1882, Bull. Mus. Comp. Zool. at Harvard Coll., vol. 9, p. 295; 1883, Bull. Mus. Comp. Zool. at Harvard Coll., vol. n, p. 85, plate I, fig. II. — ALLMAN, 1871, Monog. Tubul. Hydroids, p. 423. — HINCKS, 1868, British Hydroid Zooph., vol. i, p. 123. — VANHOFFEN, 1891, Zool. Anzeiger, p. 443. — HARTLAUB, 1894, Wissen. Meeresuntersuch. Komm. Deutsch. Meere Kiel, Abth. Helgoland (l), Bd.l, p. 188; 1907, Nordisches Plankton, Nr. 12, p. 93. — BROWNE, 1905, Proc. Roy. Soc. Edinburgh, vol. 25, p. 748. This genus was founded by L. Agassiz, 1862, the type species being E. dumortieri which was first described by Van Beneden, 1844, from the coast of Belgium under the name Tubu- laria dumortien. GENERIC CHARACTERS. Codonidae with 2 or 4 simple, unbranched tentacles situated at the bases of 2, or of all, of the 4 radial-canals. 8 longitudinal rows of nematocysts extend from the 4 tentacle-bulbs over the surface of the exumbrella to the apex of the bell. The manubnum is short and blunt, and the mouth is a simple, round opening. The hydroid is Ectopleura, and is closely related to Tubularia. FIG. 33. — Eucodonium brownei, after Browne, in Proc. Zool. Soc. London. FIG. 34. — Hydroid of Ectopleura dumortien ANTHOMEDUS.E — ECTO PLEURA. 69 The discovery of Ectopleura pacifica and E. minerva makes it necessary to amend the generic definition to include medusae with 2 as well as with 4 tentacles. Ectopleura is distinguished from Zaticlea by its unbranched tentacles. Ectopleura dumortieri L. Agassiz. Plate 5, figs. 4, 5; plate 6, figs. I, i', 2. LITERATURE RELATING TO THE EUROPEAN MEDUSA. Tubularia dumortieri, VAN BENEDKN, 1844, Mem. Acad. Belgique, tome 17, p. 50, plate I. — JOHNSTON, 1847, Hist. British Zoophytes, p. 50, plate 7, figs, i, 2. Ectopleura dumortieri, AC;ASSIZ, L. 1861, Cont. Nat. Hist. U. S., vol. 4, p. 342. Eclofleura dumortieri, HINCKS, 1868, Hist. British Hydroid Zoophytes, p. 124. Ectopleura dumortieri, ALLMAN, 1871-72, Monog. Tubularian Hydroid s, p. 424. — BOHM, 1879, Jena. Zcitschrift fiir Naturw., Bd. 12, p. 198, taf. 7, figs. 10-13. — HAECKEL, 1879, Syst. der Medusen, p. 22. Non Ectopleura dumortieri, GRAEFFE, 1884, Arbeit. Zool. Inst. Wien, Bd. 5, p. 354. Ectoflfura dumortieri, HARTLAUB, 1894, Wissen. Meeresuntersuch. Komm. Meere Kiel, Helgoland (i), Bd. I, p. 188. — BROWNE, 1905, Proc. Roy. Soc. Edinburgh, vol. 25, p. 748. Ectopkura dumortieri, HARTLAUB, 1907, Nordisches Plankton, Nr. 12, p. 94, figs. 90, 91. Tubularia dumortieri, BEDOT, 1905, Revue Suisse de Zool., tome 13, p. 126 (citation of literature, 1844-48). LITERATURE RELATING TO THE AMERICAN MEDUSA. Ectopleura ochracea, A. AGASSIZ, in L. Agassiz's 1862, Cont. Nat. Hist. U. S., vol. 4, p. 343. — AGASSIZ, A., 1865, North Amer. Acal., p. 191, figs. 320-323. — HAECKEL, 1879, Syst. der Medusen, p. 22. — FEWKES, 1882, Bull. Mus. Comp. Zool. at Har- vard College., vol. 9, p. 295, plate I, figs. 15, 16, 35, 36. — NUTTING, 1901, Bull.U. S. Fish Commission, vol. 19, p. 373, fig. 82. — HARGITT, 1904, Bulletin Bureau of Fisheries U.S., vol. 24^.32, plate 2, fig. I. — AGASSIZ, A., and WOODWORTH, 1896, Bull. Museum Comp. Zool. at Harvard College., vol. 30, p. 149, plate 6, fig. 6 (photograph of the medusa). Ectopleura, sp., HARGITT, 1908, Biol. Bulletin, vol. 14, p. 106, figs. 8-1 1. The finding of the hydroid of our American Ectopleura "ochracea" leads me to believe that there are no specific differences between the European and American forms, and that both should be called Ectopleura dumortieri, this being the older name. Hartlaub, 1907, however, believes that E. dumortieri is smaller and has somewhat thicker bell-walls than E. ochracea, but our American medusa varies considerably in these respects, as do also speci- mens which I captured in the English channel in IQO". The following description is based upon a study of large numbers of specimens obtained at Newport, Rhode Island, United States. Adult medusa. — The bell is pyriform and is about 3 mm. high and 2.5 mm. wide. The gelatinous substance is very thick and is especially so at the aboral pole. 8 longitudinal lines of nematocyst-cells extend over the surface of the exumbrella from the basal bulbs of the 4 tentacles to the bell-apex, where they meet in a point. There are 4 equally developed, short tentacles with large basal bulbs. The outer surface of these tentacles is thickly covered with nematocyst-cells, and their distal ends are coiled in a close helix. Velum narrow. There are 4 narrow, straight radial-canals and a simple, narrow, circular tube. The manubrium is fusiform and extends not more than two-thirds the distance from the inner apex of the bell-cavity to the level of the velar opening. There is no peduncle, and the mouth is a simple round opening, the edge of which is armed with clusters of nematocysts. A short, blunt, axial canal is often seen projecting upward from the stomach into the gelatinous substance of the apex of the bell. The gonads are developed in the ectoderm encircling the stomach. In brilliant specimens the tentacle-bulbs are yellow with a red core. The middle region of the entoderm of the manubrium is lilac-colored, the upper part delicate yellow, and the lower end red or pink, but very often the medusa is dull purple or dull brownish-purple. Hydroid. — The hydroid shown in plate 6, figs. I, I'was found in August, in Newport Harbor, Rhode Island, at a depth of about 10 fathoms. It is a Tubularian belonging to the family Hyboconidas Allman, and is apparently identical with 'Tubularia (Ectopleura) dumortieri of Van Beneden, 1844. The hydroid is about 25 mm. in length, and was found clinging to the stems of Obelia. The stems of the Ectopleura are isolated. Most of them are simple and unbranched, but occasionally they give rise each to a single side branch near the lower end. The lower end of the Ectopleura is coiled around the stem of the Obelia in a close helix. The stem of the Ectopleura 6 70 MEDUSAE OF THE WORLD. is covered by a delicate investment of perisarc which displays a number of small annulations near the upper end. The stem terminates in a single, large polypite, which is broad and flask-shaped. The mouth is situated at the extremity of a tubular proboscis, and is sur- rounded by a single verticil of about 16 short, flexible tentacles. In addition to these there is another verticil of about 24 long, fleshy tentacles at the wide base of the polypite. These long tentacles are not very contractile. They taper gradually from base to end. The tentacles at the base of the polypite are about three times as long as are those surrounding the mouth. The medusa-buds are borne in numbers on short, branching peduncles which arise from the sides of the polypite in a zone immediately above the basal tentacles. When set free each medusa has 4 short tentacles, and the 8 longitudinal rows of nematocysts upon the exumbrella are well developed. The ectoderm of the stem of the hydroid is a delicate, fleshy-yellow and the entodermal core is flesh-colored pink. The entoderm of the polypite is fleshy-pink and yellow. This medusa is very common throughout the summer in Narragansett and Buzzard's Bays, and on the southern coast of New England east of New Haven, Connecticut. It has not been taken north of Cape Cod. It has been recorded from Beaufort, North Carolina, and I found it in Winyah Bay, South Carolina, but it has not been taken either at Charleston, South Carolina, or at the Tortugas, Florida. It is found in the English Channel and off the North Sea coasts of England, Scotland, Holland, and Germany. As in America, it appears to be abundant only in a few localities. I found several specimens of this medusa in the English Channel in October, 1907, and they appear to be identical in all respects with medusx from the southern coast of New England, in America. Hargitt has recently discovered the hydroid at Woods Hole, Massachusetts. Ectopleura minerva Mayer. Plate 5, fig. 3. Ectopleura, sp., FEWKES, 1883, Bull. Mus. Comp. Zool. at Harvard College, vol. II, p. 85, plate I, fig. n. Ectopleura minerva, MAYER, 1900, Bull. Mus. Comp. Zool. at Harvard College, vol. 38, p. 31, plate 16, fig. 38; plate 37, fig. 125. ( ?) Ectopleura dumortieri, GRAEFFE, 1884, Arbeit. Zool. Inst. Wien, Bd. 5, p. 354. This medusa has 2 well-developed and 2 rudimentary tentacles, instead of 4 equally developed tentacles as in the northern species of Ectopleura. Bell 2.5 mm. high and pear-shaped, with a well-developed apical projection. Bell-walls of moderate thickness. 8 rows of nematocyst-cells extend from the 4 tentacle-bulbs to the apex of the bell. There are 2 well-developed tentacles and 2 small tentacle-bulbs. There are 6 to 9 separate wart-like swellings upon the outer side of each of the 2 large tentacles. These swellings are crowded with nematocysts. Basal bulbs of tentacles small and without ocelli. There are 4 straight, narrow radial-canals and a slender, circular vessel. The velum is well-developed. Manubrium pear-shaped and about two-thirds as long as the depth of the bell-cavity. It is wider near the middle than at either end. The mouth is a simple, round opening. A simple, short, conical style-canal extends upward into the apical projection of the bell. The entoderm of the manubnum and tentacles is a delicate purple, while the supporting lamella of the bell is of a decided green. There are a large number of brilliant yellow spots in the entoderm of the radial-canals and tentacle-bulbs. This form is rare at Tortugas, Florida. It was found by Fewkes at the Bermudas. A similar medusa was described by GraefFe, 1884, from Trieste, Mediterranean, under the name Ectopleura dumortieri. Ectopleura minerva may prove to be identical with E. pacifica Thornely, from the tropical Pacific. Ectopleura pacifica Thornely. Eclopleura pacifca, THORNELY, 1900, Zool. Results, A. Willey, Part 4, p. 452, plate 44, figs, i, la, Cambridge, England. Hydroid. — Stems simple, unringed, diminishing in width toward the base, and 20 mm. high, rising from a creeping stolon which connects the colony. Some of the stems give rise to stolons near their bases. The polypite is abruptly marked off from the supporting stalk. ANTHOMEDUS.E — ECTOPLEURA, CORYNITIS. 71 There are two verticils of tentacles of 18 to 20 each. The basal tentacles are very long, and the oral ones are short, and with knob-shaped ( ?) ends. The medusa-buds are borne in clusters of from 7 to 9 on branched peduncles, which arise from the body of the polypite between the two verticils of tentacles. When about to be set free each medusa-bud has 2 well-developed tentacles, thus resembling E. minerva of Tortugas, Florida. E. pacifica is common in Blanche Bay, New Britain, South Pacific. It is attached to floats, fish-baskets, etc. Color ( ?) This hydroid may be identical with E. minerva of the tropical Atlantic coast of North America. Genus CORYNITIS McCrady, 1857. Corynitis, McCxADY, 1857, Gymn. Charleston Harbor, Proc. Elliott Soc. Charleston, p. 29. — AGASSIZ, L., i86z, Cont. Nat. Hist. U. S., vol. 4, p. 340.— AGASSIZ, A., 1865, North Amer. Acal., p. 1 83 .— ALIMAN, 1871, Monog. Tubularian Hydroids, p. 286. Coryneles, HAECKEL, 1879, Syst. der Medusen, p. 48. PlolocniJc, WAGNER, 1885, Wirbelloscn Weissen Meeres, p. 74. Corynttcs, VANHOFFEN, 1891, Zool. Anzeiger, Bd. 14, p. 442. iV,-ri Nordisches Plankton, Nr. i*, p. 91, fig. 87 (88?). This is a small spindle-shaped, free-floating hydranth, with a sucker-like expansion at its aboral pole, and with three verticils of tentacles, i. e., 4 short-knobbed oral tentacles, a 7 82 MEDUSA OF THE WORLD. middle zone of about 10 to 12 long-knobbed tentacles, and a basal (aboral) zone of" about 10 to 12 long-knobbed tentacles. Medusa-buds (?) This form closely resembles Tiarella singularis F. E. Schulze, 1876, a small, isolated, attached hydroid found at Trieste. T ' . singu- lans produces medusa at the base of the polypite below the third zone of tentacles. Margelopsis stylostoma was found at Roscoff, northwest coast of France, in June. FIG. 39. — Hydroid of Margelopsis stylostoma, after Hartlaub, in Nordisches Plankton. FIG. 40. — Margelopsis hartlaubii, after Browne, in Bergens Museums Aarbog, 1903. Margelopsis hartlaubii Browne. Margelopsis hartlaubii, BROWNE, 1903, Bergens Museums Aarbog, No. 4, p. 10, plate i, fig. 2, plate 3, fig. 3. — HARTLAUB, 1907, Nordisches Plankton, Nr. 12, p. 92, fig. 89. Bell 2 mm. wide, 2 mm. high. Egg-shaped, with thick walls. 8 marginal tentacles, 2 upon each radially placed marginal bulb. These tentacles are ringed with nematocysts, and are somewhat shorter than the bell-diameter. No ocelli. 4 narrow radial-canals. Stomach large, conical, with a broad, flat, quadrangular base, without an axial, apical canal. Mouth a simple, round opening. Gonad encircling the stomach. Color (in formalin): Gonads, stomach, and tentacle-bulbs yellowish-brown. Three specimens; coast of Norway, Osterfjord and Herlfjord, from depths of o to 200 fathoms. Margelopsis gibbesi Hartlaub. Plate 9, figs. 4-7. Ncnwpsis gibbesii, McCfiADY, 1857, Gymn. Charleston Harbor, p. 163, plate 10, figs. 4-7. — FRECH, 1898, Lptli.ua pali,l, twice natural size. b, enlarged view, showing medusa-buds developing among tentacles. 84 MEDUSA OF THE WORLD. This family is of such interest that we devote more than the usual space to its consider- ation. Haeckel, 1879, classifies it as a family coordinate with the Codonidae, but Hartlaub, 1887, showed that the genus Cladonema had an encircling gonad as in the Codonidae. The medusa; are, however, highly specialized, both in respect to their anatomy and their mode of life, and they are undoubtedly derived from some more simply-organized medusae among the Codonidae. The hydroid of Cladonema is a StanriJia, and is closely related to Syncoryne, the hydroid of Sarsia. CHARACTERS OF THE FAMILY CLADONEMID^. Anthomedusae with feathered or branched marginal tentacles, and with four or more simple or branched radial-canals. The gonads may be ring-like and encircle the stomach, or they may be more or less separated so as to be interradial or adradial, or developed in a spec- ialized brood-pouch above the stomach. Hartlaub, 1887, and Perkins, 1902, show that in the genus Cladonema the genital products are developed over the entire gastric portion of the manubrium and the gonads are not con- fined to restricted meridians, as was believed to be the case by Haeckel. Hartlaub found that in Cladonema radiatum of the Mediterranean the genital products begin to develop in the ento- derm. This species exhibits a successive hermaphroditism, although either sperm or ova may precede. Perkins, however, in his study of Cladonema pcrkinsn of the Bahamas, found that the genital products were developed in the ectoderm of the manubrium, and he failed to find sperm or ova in the entoderm. In Eleutheria, Hartlaub, 1 886, 1887 (Zool. Anzeiger), showed that the genital products are developed exclusively in the ectodermal lining of a peculiar brood-pouch above the stomach, and that the medusa is hermaphroditic. The brood-pouch is derived from the ectodermal layer of the bell-cavity and is not connected with the stomach of the medusa, but communi- cates with the bell-cavity by means of 6 interradial-canals. Hartlaub, 1887, divides the Cladonemidae into two groups, one with and the other without an apical brood-sac above the stomach. As this brood-sac is highly variable in its develop- ment, some specimens of Eleutheria apparently failing to develop it and, moreover, as it is a character which develops during the growth of the medusa and is not found in the young animal, it would seem that Haeckel's classification of the Cladonemidae, based as it is upon the possession of constant characters, is to be preferred. Moreover, as has been shown by Giinther, 1903, we can not yet state that the brood-pouch of other genera of Cladonemidae is similar in structure to that of Eleutheria. As is well known, Haeckel, 1879 (Sitzungsber. Medicin. Naturwiss. Ges. Jena; see also Chun, 1880, Ctenophoren des Golfes von Neapel), drew an ingenious comparison between Ctenaria and the Ctenophorae, and concluded that the Ctenophorae might have been derived from some form of Anthomedusa. Ctenaria appears to resemble the Ctenophorae in its 2 feathered tentacles, 4 bifurcated radial-canals, and in a peculiar sheath at the base of each tentacle. However, Hartlaub's discovery that the brood-pouch in the closely-related Eleu- theria is of ectodermal and not entodermal origin makes it appear that the resemblances between Ctenaria and the Ctenophorae are of the nature of a mere parallelism and not indic- ative of a genetic relationship. Haeckel compared the 8 adradial longitudinal lines of nematocysts upon the exumbrella of Ctenaria with the 8 rows of ciliated combs in the Ctenophorae. An even more remarkable case of convergence is shown by Kofoid, 1905 (Bull. Mus. Comp. Zool. at Harvard College, vol. 46, p. 163, i plate), in the case of the Cystoflagellate, CraspeJotella, which is bell-shaped and provided with a well-developed velum, the walls of which are contractile so that the mode of locomotion is similar to that of a medusa. There is thus an external similarity of form between this protozoan and a medusa offering an instance of convergence of a most striking character. Another remarkable instance of conver- gence is that of the pelagic holothurian Pelagothuria natatrix, which bears a close resemblance to a medusa (see Mem. Mus. Comp. Zool. at Harvard College, vol. 17, 1894). I believe also that the bell of the Narcomedusa? is not homologous with that of the Anthomedusae and Leptomedusae, but is a mere outgrowth from the walls of the actinula larva. ANTHOMEDUS.E — ZANCLEA. 85 The Cladonemidae are close relatives of the Codonidae, this being illustrated most cleaily by their hydroids, and they may properly be regarded as highly-specialized Codonidae, as has been maintained by Hartlaub. For purposes of classification, however, I think it will be well to permit them to remain in a family of Anthomedusae coordinate with the Codonidae, for there is no single character which they have consistently in common with the Codonidae. For example, the gonad in ClaJonemamzy be readily likened to that of the Codonidae, for it encircles the stomach on all sides, but in some species of Zanclea the gonads show a decided tendency to segregate interradially, and in Elcutheria they are developed in an ectodermal brood-sac which is not connected with the manubrium. The most constant character of the Cladonemidae is their forked, or feathered, marginal tentacles. The greatest difficulty in any attempt to classify the Cladonemidae among themselves arises from our lack ot understanding of the nature of the brood-sac or apical cavity in the bell ot the genera Pteroncma, Ctenarta, and Dendronema; and no classification worthy of serious consideration can be effected until we know whether this sac is a mere extension of the stomach or an ectodermal reproductive cavity similar to that studied by Hartlaub in Elcutheria. FAMILY: CLADONEMIDAE. Subfamily Pteroneminai Manubrium without oral tentacles. With 4 to 8 simple radial-canals. Zanclea GEGENRAUR, 1856. With 2 to 4 marginal tentacles at bases of 4 radial-canals. The tentacles give rise to an abaxial row of simple branches, each terminating in a cluster of ncmatocysts. With meridional rows of nema- tocysts upon the exumbrella. No ocelli. No brood-pouch above the stomach. The hydroid is Gtinmaria McCrady, Allman. Zancleofish HARTLAUB, 1907. Similar to Zanclea, but with tentacular ocelli and without meridional rows of nemato- cysts. Pteronema HAECKEL, 1879. With 4 well-developed tentacles similar in structure to those of Zanclea. With 4 simple radial-canals. With a brood-sac above the stomach. Hydroid unknown. Eleutheria QTATREFAGES, 1842. With 4 to 6 simple radial-canals, and an equal number of bifurcated tentacles. With a brood-pouch above the stomach. This brood-pouch is not connected with stomach-cavity, but communicates \vith bell-cavitv by means of simple interradial pores. Genital products develop exclusively in brood-pouch. Medusa is hermaphroditic. Hydroid is Clavatella Hincks. Mnestra KROHN, 1853 (Archiv. fur Naturges., Jahrg. 19, Bd. i, p. 278). Medusa degenerate, sessile upon Pliyllirhoc in the Mediterranean. With 4 to o small marginal tentacles having nettling capsules along their abaxial sides. A ring of nematocysts extends around the bell-margin, and 4 linear tracts of nettle-cells extend upward over the exumbrella, t from each tentacle-bulb. With 4 simple, unbranched radial-canals and ring-canal. No brood-pouch above stomach. Throat of medusa blocked by a spongy mass of entoderm. Medusa attaches itself by its mouth to throat of Phyllirhoe, and the larvae of the Mnestra probably develop within the gastric cavity of the Phyllirhoe* It is elaborately described by Gunther, 1903 (Mitt. Zool. Sta. Neapel, Bd 16, pp. 35-62, plates 2, 3). FAMILY: CLADONEMID.'E. Subfamily Dendroneminte: The mouth is surrounded by simple, or branched, oral tentacles. Some or all of the radial-canals bifurcate. Ctrnaria HAECKEL, 1879. With 2 marginal tentacles, each of which gives rise to a row of nematocyst-bearing filaments. With 4 bifurcated radial-canals. With simple, unbranched, oral tentacles. With an apical sac above the stomach. Hydroid unknown. Clailonema DTJARDIN, 1843. With 4 to 5 bifurcated radial-canals, or 8 to 10 simple radial-canals, or with both simple and bifurcated radial-canals. With a tentacle at foot of each radial-canal. These tentacles branch dichotomouslv or complexly, and branches end in suckers or nematocyst-knobs. With simple, unbranched, oral tentacles. No brood-sac above stomach. Hydroid, Siauridia Dujardin. Deridroneiiia HAECKEL, 1879. With bifurcated radial-canals, and dichotomously branched tentacles. Branches end in suckers, or in nematocyst-knobs. Mouth surrounded by 4 groups of dichotomously branched oral tentacles. There is an apical sac above the stomach. Genus ZANCLEA Gegenbaur, 1856. Zanclea, GEGENBAVR, 1856, Zeit. fur wissen. Zool., Bd. 8, p. 229. — KEFERSTEIN UNO EHLERS, 1861, Zool. Beitr. in Xt-apcl und Messina, p. 85. — AGASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 344. Zariflea-t- Gemtntiriii, HAE( KEI., 1879, Syst. der Mcdlisen, pp. IO2, 103. Zanclea, FEWKES, 1881, Bull. Mus. Comp. Zool., vol. 8, p. 150. — HARTLAI/B, 1887, Zoo], Anzeiger, Bd. 10, p. 654; njo^, N'or- dischcs Plankton, Nr. 12, p. 112. — VANHOFFEN, 1891, Zool. Anzeiger, Jahrg. 14, p. 445. K. i'|o}. Mitt. Zool. Sta. Neapel, Bd. 16, p. 57. Gemmaria= Zanclea, BROWNE, 1905, Proc. Roy. Soc. Edinburgh, vol. 25, p. 750. Gemmaria, McCfiADY, 1857, Gymn. Charleston Harbor, p. 49. — A<:», i '. \ . iSi^, North Amcr. Acal., p. 184. An \nx, 1872, Monog. Tubul. Hvdroids, p. 289. — BROWNE, 1896, Proc. X.ool. Sot. London, p. 4111. \'on Gemmaria, FEWKES, 1881, Bull. Mus. Comp. Zool. at Harvard I'. .Hi vol. 8, p. 150. • Gemmaria, HARTLAI'B, 1887, Zool. Anzeiger, Bd. 10, p. 6^4. -fJiM'Hm, [903, Mitt. Zool. Sta. Neapel, Bd. if>, p. 57. Gemmaria (hydroid), HARTLAI R, 190$, Zoologischen Jahrbiich., Supplement 6, p. 527. Corvnith, Mi r. i:v 11. 1^90., Quart. Journ. M ici., new ser., vol. 42. p. ^4. \t TTING, 1901, Bull. I'. S. Fish Commission for iScfij, pp. ^29, 372. — HARGITT, 1904, Bull. U. S. Bureau uf Fisheries, vol. 24, p. 42. Halorharis (hydroid), Ai.tssiz, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 239, plate 20, figs. io-ioc. Gemmaria+ Zanclea, HARGITT, 1908, Biol. Bulletin, vol. 14, p. 104. The type species of this genus is Zanclea costata Gegenbaur, 1856, of the Mediterranean. Mi MEDUSAE OF THE WORLD. Tabular Description of the Medusa of Zanclea. Z. costata Gegenbaur, 1856. Z. gemmosa McCrady, 1857- Z. implexa Allman,i864 Z. cladophora = Gem- maria cladophora A. Agassiz, 1865. Shape and size of bell in mm. Ellipsoidal. 4 to 5 high, 3 to 4 wide. Pyriform. 6 high, 4 wide. Dome-like to globular. 1.5 high, 1.75 wide. Pyriform. Size (?) Length of the 4 merid- ional rows of nettle- cells above tentacle- bulbs, in terms of From tentacle-bulbs to very near a pex of bell . One-fourth to one-third distance from margin to apex. 0.25 to 0.5 °-5 bell-height. Number and length of tentacles in terms of bell-radius (r). 4 tentacles, each 3 to 4 r long- 4 tentacles, each 3 to 4 r long. 2 to 4 tentacles, each about 4 r long. 2 long and 2 short ten- tacles; long tentacles 4 r, short over one-third r long. Character of abaxial filaments upon ten- tacles. Very numerous, slender, and ending in a spheri- cal capsule containing 3 to 5 nematocysts. Very numerous, slender, and ending in a spheri- cal capsule containing 3 to 9 nematocysts. Very numerous, slender filaments, each ending in an oval capsule containing 4 to 8 nematocysts. Very numerous, slender filaments, ending in knob-like clusters of nematocysts. Num- ber of nematocysts in each knob ? Length and shape of manubrium. Not quite half as long as depth of bell-cavity. Flask-shaped. Flask-shaped, 4-sided. As long as depth of bell-cavity . Mouth with 4 small lips. Urn-shaped. Only half as long as depth of bell-cavity. Mounted upon short peduncle. Mouth round opening. Conical. 4 prominent lips. Gonads. 4 interradial masses of eggs on swollen sides of stomach. On 4 interradial sides of stomach. Much swollen. On upper sides of stomach, more or less separated in 4 chief radii. Gonad encircles stom- ach. Color. Gonads red, tentacles yellowish-brown. Entoderm of stomach and tentacle-bulbs creamy-pink. Ento- derm of manubrium delicate green. Stomach and tentacle- bulbs brownish-red to crimson. Entoderm of tentacles orange. Tentacles light-brown. Orange and yellow spots in tentacle- bulbs. Color of stom- ach ( ?) Where found. Mediterranean. Common. Medusa having only 2 tentacles, but in other respects similar to Z. costata found at Tor- West Indies northward to Woods Hole. Atlantic coasts of west- ern Europe to Medi- terranean. Coast of Massachusetts, Nahant, Woods Hole. tugas, Florida. Hydroid. Hydroid ( ?) (see text). Hydroid: Gemmaria gemmosa. Hydroid: Gemmaria implexa. Hydroid unknown. GENERIC CHARACTERS. Cladonemidae with 4 simple radial-canals, and 2 to 4 radially situated tentacles which give rise to filiform, knobbed, nematocyst-bearing side branches. The gonad is developed upon the sides of the stomach. There is no apical brood-pouch above the stomach. There are merid- ional lines of nettle-cells over the exumbrella. There are no tentacular ocelli. The hydroid is Gemmaria Allman, 1871. In 1857, McCrady founded the genus Gemmaria for a Zanclea-\ike medusa with only 2 tentacles. Vanhoffen, 1891, and Browne, 1905, have observed that the 2-tentacled young of other species of these medusae often becomes 4-tentacled when adult, and according to Browne, 1905, "Gemmaria" implexa may become mature with 2 or with 4 tentacles. It is evident, therefore, that there are no definite generic distinctions between Zanclea and Gemmaria, the "Gemmaria" condition being only a developmental or retarded phase of Zanclea. Murbach and Nutting have erroneously applied the name "Corynitis" to a 2-tentacled medusa of Zanclea. Apparently these authors had not seen the medusa of Corynitis, which is ANTHO.MKDCS.E — ZANCI.KA. well figured by McCrady. I have frequently taken Corynitis in Charleston Harbor, South Carolina, where McCrady discovered it, and it is wholly different from any "Geniniaria" or Zanclea. (See also Hargitt, 1908.) The common '/aticli-a ot the southern coast of New England, in America, may become mature with only 2 tentacles, and with poorly developed lips. On the other hand, a vcrv similar medusa is occasionally found in the same waters with 4 tentacles and with 4 well- developed lips. I am inclined to believe that these conditions represent developmental staues. or starved and well-fed states of one and the same medusa. Zanclea costata Gegenbaur. Plate 8, figs, z, 3, 6, and 7. Zanclea conaia, GEGENBAUR, 1856, Zeit. fur wisscn. Zool., Bd. 8, p. 229, taf. 8, figs. 4-7. — HAECKEL, 1879, Syst. dcr Mcdu sen p. 103. Hydroid ( ?), MAYER, 1900, Bull. Mus. Comp. Zool. at Harvard College, vol. 37, p. 35, plate 41, figs. 137, 138. Gegenbaur found many specimens of this medusa in the Mediterranean. His fully developed medusae had 4 long, equally developed tentacles. For details see tabular description of the medusae of Zanclea. I have found a medusa at Tortugas, Florida, which accords well with 7, ancle a costata, excepting that it has but 2 tentacles. Medusa from Tortugas, Florida. — Bell 6 mm. high and ellipsoidal, with bluntly-rounded apex. Without an apical projection. Bell-walls of uniform thickness everywhere. There are 2 long, spindle-shaped, rough-looking tentacles somewhat longer than the bell-height. These are thickly covered with papillae and beset on their outer sides with a row of filaments, each of which ends in a spherical knob, the surface of which is covered with blunt papillae. Each of these knobs contains a cluster of nemato- cysts (plate 8). Basal bulbs of tentacles are elongate, spindle- shaped, and hollow. No traces of tentacle-bulbs 90° away from the 2 long tentacles. 4 swollen lines ot nematocysts extend upuaul over the exumbrella from the bases of the 4 radial-canals and nearly meet near the apex of the bell. Velum well developed. 4 radial-canals, and the circular vessel straight and narrow. Manu- brium flask-shaped, with 4 simple lips. Entoderm of the manu- brium and tentacles milky white, There were 4 interradial gonads. A single specimen was found in a surface-tow at Tor- tugas, Florida, on May 15, 1906. This species is distinguished by its ellipsoidal, high, rounded bell, without a sharp-pointed apex, the 4 very long meridional lines of nematocysts over the exumbrella, and the spherical nematooyst- capsules at the ends ot the tentacular filaments. The Tortugas medusa differs from //uiclea cost. V. i. dcr Medusen. p. 105. — JICKELI, 1883, Morphol. Jahrbuch, Bd. 8, p. 6n, taf. 26 (hi-riiWv ). CKJ, N-.4. Arbeit Zool. In.st. \Vien, Bd. 5, p. 353. — BROWNE, 1896, Proc. Zool. Soc. London, p. 461.— HARI.ITT, 1904. Mnth. /.nol. Si.iiinn Neapel, Bd. 16, p. 574, taf. 22, figs. 27-29 (hydroid and medusa from the Bay of Naples). BKOWNI, 1905, Proc. Roy. Soc. Edinburgh, vol. 25, p. 750. This medusa is closely related to /.unclea gemmosa of the Atlantic coast of the I'mted States, but it is much more swollen than the American form, and differs in other n-spivts. The bell is globular with fairly thin side walls and a thick, solid, dome-like apex. It is 1.5 mm. high, 1.75 mm. wide. There are 4 prominent nematoryst tracts extending one- fourth to half the distance from the tentacle-bulbs up the sides of the bell, and the nettle- cells in each tract are arranged in two rows. There are usually 2 long tentacles 1 80° apart alternating with 2 short tentacle-bulbs, but according to Browne, 1905, the medusa may become mature with 2 or with 4 long ten- tacles. The long tentacles are about twice as long as the bell-diameter and their upper, abaxial sides bear each a double row of numerous filaments, which terminate in oval capsules containing 4 to 8 nematocvsts. The basal bulbs of the tentacles are globular, and lack ocelli. There is a slight linear (glandular?) swelling occupying the middle third of each of the 4 radial-canals. The stomach is mounted upon a short peduncle and is urn-shaped, with a simple, round mouth-opening. The gonads surround the stomach and are more or less 90 MEDUS/E OF THE WORLD. separated in the 4 principal radii. The basal bulbs of the tentacles and the stomach are brownish-red to bright crimson, and the entoderm of the tentacles is orange. This medusa is found off the Atlantic coasts of Western Europe, and in the Mediter- ranean. Graeffe, 1884, states that at Trieste, Adriatic Sea, the medusae bud forth from the hydroids in the spring, and a second brood appears to develop in summer. The hydroid is Gemmaria implexa, well described and figured by Allman, 1871-72. The stems of the hydroid are erect, 6 to 8 mm. high, and arise at intervals from a creeping, net-like hydrorhiza which is attached to shells, stones, etc., in shallow water. The stems are usually single, but occasionally they branch. The perisarc covers the hydrorhiza and extends as a transversely corrugated, opaque tube up the lower part of each hydranth. Below the zones of tentacles the perisarc becomes abruptly smooth, and ends in a slightly flaring cup. The hydranths are cylin- drical to club-shaped, with dome-like peristome. There are 40 to 50 short tentacles, each ending in a knob of nematocysts. These tentacles are ar- ranged in 10 to 13 irregular verticils of about 4 tentacles each, the tentacles being about 90° apart. The medusa- buds are borne upon peduncles which arise in clusters from the sides of the hydranth below the middle, but above the lowermost verticils of tentacles. When set free the medusa has 2 well-developed tentacles which give rise to numerous filaments, each ending in a capsule bearing terminal bristles and containing several nematocysts. There are also 2 small tentacle-bulbs 90° apart from the well-developed ten- tacles. The bell is oval and higher than a hemisphere and 4 lines of nematocysts extend up about one-fourth to one-third of the bell-height, one above each tentacle-bulb. The 4 radial-canals are straight and simple, and the manu- brium is a simple tube with a round mouth-opening and straight cylindrical Fie. 43.— Hydroid of Zanclea implexa, after Allman, in Ray sides. It lacks a peduncle and is about Society, 1871-72. See also, Fig. 44. nalf as long as depth of bell-cavity. The hydranths are white with pale-pink entoderm. The perisarc on the proximal portion of the hydrocaulus is brown and on the distal portion, colorless. It is closely related to the hydroid of Zanclea gemmosa. Zanclea cladophora Hartlaub. Gemmaria cladophora, AGASSIZ, A., 1865, North Amer. Acal., p. 184, figs. 307-310. — HAECKEL, 1879, Syst. der Medusen, p. 104. — NUTTING, 1901, Bull. U. S. Fish Commission for 1899, vol. 19, p. 371, fig. 78. — HARGITT, 1904, Bull. U. S. Bureau of I-' i .lirrn-s, vol. 24, p. 42. Zanclea cladophora, HARTLAUB, 1907, Nordisches Plankton, Nr. 12, p. 121, fign. 112-115. Bell pyriform and about as broad as high. Apical projection solid, rounded, and dome- like. There are 2 long, diametrically opposed tentacles from the outer sides of which arise a great number of slender filaments, each terminating in a knob-like body which contains ANTHOMEDUS.E — ZANCLKA. XAM MXH'SIS. 91 nematocysts. These long tentacles are 1.5 times as long as the bell-diameter. There are also 2 small, conical tentacles 90° apart from the long ones. The small tentacles do not give rise to side-filaments. No ocelli. A ridge of nematocyst-cells extends from the base ot each ten- tacle about half-way up the side of the exumbrella. Velum broad. There arc 4 broad radial- canals and a narrow circular tube. The outline of the bell-cavity does not follow that of the outer surface of the bell, but is widest at the inner apex. Manubrium conical, with a wide- proximal base and regularly-narrowing sides. It does not extend quite to the level ot the velar opening. The 4 lips are quite prominent, and the mouth is a rectangular opennm. The mouth is surrounded by 2 or 3 rows of large nematocyst-cells, similar to those found upon the sides of the exumbrella. The gonad is developed upon the sides of the stomach, which it encircles. The tentacles are light-brown in color, and the entoderm at their bases contains orange pigment. There are bright-yellow pigment-spots at the bases ot the two rudimentary tentacles. This species was found at Xahant, Massachusetts, in 1862, by Dr. Alexander Agassiz. Nutting, 1901, obtained it at Woods Hole, Massachusetts, in August, 1899. Neither of these observers states the dimensions of the medusa. The peculiar outline ot the subumbrella and the constriction above the lips figured by A. Agassiz may be due to unnatural contraction. Many of the characters of this so-called remain in doubt. species Zanclea nitida. Gtmmaria nitida, HARTLAI B, 1905, Zoolog. Jahrbiichrrn. Suppl. 6, p. 527, fign. J, H (hydroid). PolvpitesaboutS mm. long. Club-shaped rio. 44. — Zanclea ini[>lc\a, after Hartlaub, in Norillschcs rlankton. - ' . to cylindrical, with about 50 short knobbed tentacles, irregularly distributed. Hypostome short and flatly conical. Each polvpite IK i i to 3 clusters of small medusa-buds. These are borne upon short branching stems which arise between the tentacles near the lower, basal part of the polypite. The condition of the medusa is not described. Found at Juan Fernandez Island, off the Pacific coast of South America. Genus ZANCLEOPSIS Hartlaub, 1907. ZancleopaSf HARTLAUB, 1907, Nordisches Plankton, Nr. 12, pp. 115, 116. GENERIC CHARACTERS. Cladonemidae related to Zandca, but with large, stout, lateral branches on the tentacles. With ectodermal ocelli upon the tentacle-bulbs, and without meridional clusters of nemato- cysts upon the exumbrella. The type species, and only known form, is Zancleopsis Jichotorna, from Tortugas, Florida, described by Mayer under the name Gemimirni Jn-hotvma. This genus is distinguished from Zatiflra by the large lateral branches upon its tentacles, and by the absence of nettle-cell tracts upon the exumbrella. Also, it has < Hi, and these are not known in Y.nnclea. Zancleopsis dichotoma Hartlaub. Plate 8, fig. i. Gtmmaria dichotoma, MAYER, 1900, Bull. Mus. Comp. Zool. at Harvard College, vol. 37, p. 35, plate 17, fig. 40. Zancleoftsis dichotoma, H^RTLArn, 1907, Nordisches Plankton, Nr. 12, p. 115, fig. 105. Bell miter-shaped, with thin walls, and solid apical projection. 3 mm. high and about 2.5 mm. wide. There are 2 rudimentary tentacle-bulbs and 2 well-developed, diametrically opposed tentacles. These long tentacles are of unequal length, one being about as long as 92 MEDUSA OF THE WORLD. the bell-height, while the other is only about two-thirds this length. Each of these tentacles terminates in a club-shaped, nematocyst-beanng end. The small tentacle gives rise to 2 to 3 side branches while the large one gives rise to 4 side branches. These side branches arise from the outer (aboral) side of the tentacle, and each one terminates in a knob-like end con- taining nematocysts as in the end of the main shaft itself. The youngest and least-developed side branch is always found nearest the side of the bell, whereas the oldest is nearest the outer end of the tentacle. The basal bulbs of the tentacles are large and swollen and contain each an ectodermal ocellus upon the outer (abaxial) side of the bulb. The ectodermal core of each tentacle and of the side branches is hollow. The nematocyst bulbs of the tentacles are provided with delicate bristles. The velum is quite narrow. There are 4 straight, simple radial-canals and a narrow circular vessel. The manubrium is flask-shaped, and cruciform in cross-section, with 4 small, cruciform, nematocyst-covered lips. The stomach-cavity does not project upward into the gelatinous apex of the bell. The gonads are developed upon the interradial sides of the stomach. The entoderm of the manubrium and the circular and radial-canals is dull ocher-yellow, while the entodermal cores of the terminal bulbs of the tentacles is of a brighter yellow. The 4 ocelli (2 on the bulbs of the well-developed tentacles and 2 on the rudimentary tentacle-bulbs) are dark reddish-brown. This medusa is occasionally found at Tortugas, Florida, from May until July. It is taken each year upon the surface, but never in large numbers. This species is widely separated from other medusae of the genus Gemmana by its well- developed ectodermal ocelli upon the 4 tentacle-bulbs and by the total absence of nematocyst tracts upon the exumbrella. The "filaments" arising from the abaxial sides of the 2 long tentacles are almost as thick as the main shaft of the tentacle itselt, and in comparison with species of Gemmaria they are greatly reduced in number. This numerical disparity is, how- ever, counterbalanced by their great size. Genus PTERONEMA Haeckel, 1879. Microstoma, preoccupied by CUVIER, 1817, for Fishes. Microstoma, LESSON, 1829, Voyage autour du monde sur la Coquille, tome 2, Zooph., p. 130. Pteronema, HAECKEL, 1879, Syst. der Medusen, p. 101. — VANHOFFEN, 1891, Zool. Anzeiger, Jahrg. 14, p. 445. The first medusa to be described which belongs to this genus is Microstoma ambigua Lesson, from New Guinea. Haeckel, 1879, describes that which is probably the same medusa, in an expanded state, under the name Pteronema darwinii. This species is described from the coast of Australia, but the exact locality is not stated. GENERIC CHARACTERS. Similar to Zanclea, but distinguished by having a brood-sac above the stomach, the nature of which is unknown. If it be similar to that of Eleutlieria it has no connection with the stomach. Haeckel considers it to be continuous with the stomach, but his studies do not demonstrate this to be true, for he cut no sections. There are no meridional tracts of nematocysts upon the exumbrella in Pteronema. Pteronema darwinii Haeckel. ( ? ?) Microsioma ambigua, LESSON, 1830, Voyage de la Coquille, Zooph., tome 2, p. 130, plate 14, figs. 5, 5'. (? ?) Microslotna ambiguus, LESSON, 1843, Hist. Zooph. Acal., p. 295. (? ?) Zanclea ambigua, AGASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 344. Pteronema darwinii, HAECKEL, 1879, Syst. der Medusen, p. IOI, taf. 7, figs. I, 2. (? ?) Pieronema ambiguum, BEDOT, 1905, Revue Suisse de Zool., tome 13, p. 144 (literature, 1830-1850). Haeckel describes his Pteronema darwinii from a single specimen preserved in glycerin. He states that the preservation was good, but that the tentacles were contracted and are represented in his figure as being of double the length observed in the preserved specimen. This medusa was obtained somewhere ofF the coast of Australia. Lesson, 1830, describes a medusa under the name Microstoma ambigua from Waigion, New Guinea, which may possibly be identical with P. darwinii. Lesson's description is, ANTHOMEDUS.E — FTERONEMA, ELEUTHEHIA. 93 however, too vague to be of service, and his figure 5' is almost equally hopeless. The spherical bell is apparently turned inside out, and there are 4 short, feathered, marginal tentacles and a flaring, conical manubrium, the tentacles and manubrium being bright yellow. His figure 5 is even worse for purposes of identification. I advise the dropping of Lesson's medusa from future lists, for it will doubtless be impossible to determine it even generically. In Haeckel's medusa the bell is 6 mm. high, 4 mm. wide, pyriform with a pointed conical apex. There are no longitudinal lines of nemato- cysts over the exumbrella. There are 4 radially placed marginal tentacles, longer than the bell-height, and each provided with an abaxial row of filiform side branches, each one of which terminates in a spear-head-shaped capsule containing 5 to 10 nettle-cells. The basal bulbs of the tentacles are conical and lack ocelli. There are 4 straight, wide, jagged edged radial-canals and a narrower, smooth edged circular vessel. The stomach is spindle- shaped, halt to two-thirds as long as the depth of the bell-cavity, and provided with 4 simple lips. Gonads ( ?) on the adradial sides of the stomach. The distinguishing characteristic of this medusa is the elongate, spindle-shaped brood-pouch above the stomach in the gelatinous apex of the bell. Haeckel observed ripe eggs and gastrulae in this brood-pouch. The anatomical relationships between this brood-pouch and the stomach are unknown, and it may have no con- nection with the stomach, but be ectodermal and con- nected with the subumbrella epithelium as it is in Eleutheria, Haeckel's description affords no solution of this problem. Color ( ?) Coast of Australia. Exact local- ity unknown. A single specimen described by Haeckel. Genus ELEUTHERIA Quatrefages, 1842. Elcufhcriti, (Ji'ATRKFAr.Es, 1842, Compt. rend. Acad. Set., Paris, tome 15, p. 168; 1842, Annal. des Sci. Nat., serie 2, tome 18, p. 270. Clavatella (hydroid and medusa), HINCKS, 1861, Annals ami Mai:. Nat. Hist., scr. 3, vol. 7, p. 73. Elfutheria, KROHN, 1861, Wiegemann's Archiv. fur Natures., Jalirj;. 2-, Bd. i, p. 157. — CLAPAREDE, 1863, Beobacht. iiber wirbrllose ThiYre, p. 4. — ALLMAN, 1872. Monog. Tubul. Hydroids, p. 384. — HAECKEL, 1879, Syst. der Medusen, p. io<;. — HARTI-AVK, 1886, Zool. Anzeiger, Bd. 9, p. 707; Ibid., 1887, Bd. 10, p. 652; Iliiil., Bd. 12, p. 665, 1889; 1907, NorJisches Plankton, Nr. 12, p. 126. — BROWNE, 1902, Annals and Mag. Nat. Hist., ser. 7, vol. 9, p. 279.— GUNTHKR, 1903, Mitt. Zool. Sta. Neapel, Bd. 16, p. 57. — KRVMBACH, 1907, Zool. Anzeiger, Bd. 3 1, p. 450. FIG. 45. — Ptcronema danvinii, after Haeckel, 1879. The type species of this genus is the extremely v.i li- able Elfutheria dichotoma of the Mediterranean and Atlantic coasts of Europe. Haeckel, 1879, p. 106, records 12 subspecies of this medusa. Tin- best description is by Hartlaub, 1886, 1907. GKNKRIC CHARACTERS. Cladonemidae with 4 or more simple radial-canals and an equal number <>t biturcated tentacles. Terminal branches ot tentacles end each in a knob-like. cluster of nemntocysts. Manubrium a simple, 4 or more sided tube without oral tentacles or prominent lips. Velum well developed and there is an urticating ridge around the exumbrella side of the hell-margin below the ring-canal. There is a peculiar brood-pouch above the stomach, but this pouch is not connected with the gastrovascular cavity of the medusa. The cavity of this brood-pouch is, however, connected with the bill-cavity by means of simple, interradial openings. The genital products are developed exclusively in the epithelial lining of this brood-pouch, which is dei i\ i-d 94 MEDUS.E OF THE WORLD. from the ectoderm of the subumbrella cavity of the bell. The medusa is hermaphroditic; ova develop in the ventral, and sperm in the dorsal (aboral) wall of the brood-pouch. The hydroid is Clavatella of Hincks, 1861 (Annals and Mag. Nat. Hist., ser. 3, p. 73, plates 7, 8; Ibid., 1868, British Hydroids, vol. I, p. 73, plate 12, fig. 2). In Clavatella the polypites arise singly from a linear stolon. The polypites are small linear, or clavate, with a zone of 8 slender tentacles which terminate each in a knob of nematocysts. The medusa-buds are borne only on two opposite sides of the body of the polypite near its base. The hydroid lives on Ulva in shallow tide pools, and the medusae are produced in summer and autumn. Hartlaub found that the entoderm of the planula of Eleuthe ria contains numerous nema- tocyst-cells. Krumbach, 1907, believes that Tnchoplax, F. E. Schulze, 1891 (Abhandl. Akad. Berlin), is the creeping planula of Eleuthena. Elfuthcna, Cladonema, and Amphogona are the only genera of hydromedusae known to be hermaphroditic. Fit;. 46. — Hydroid (Clavatella prolifera) and its medusa (Eleutheria dichotoma), after Allman, in Ray Society, 1871, 1872. FIG. 47. — Clavatella prolifera, after Hincks, in British Hydroid Zoophytes. Eleutheria dichotoma Quatrefages. Eleulheria dichotoma, QUATREFAGES, 1841, Compt. rend. Acad. Sci., Paris, tome 15, p. 1 68; 1842, Annales Sci.Nat., Ser. 2, p. 270, plate 18. — KROHN, 1861, Archiv. Naturgesch., Jahrg. 27, p. 157. Clavatella prolifera (hydroid), HINCKS, 1861, Annals and Mag. Nat. Hist., ser. 3, vol. 7, p. 73, plates 7, 8; 1868, Hist. British Hydroid Zoophytes, p. 73, plate 12, fig. 2. Non Eleutheria dichotoma, CLAPAREDE, 1863, Beob. Anat. und Enrwick. wirbelloser Thiere, p. 4, taf. i, fign. 4-10. Clavatella prolifera (hydroid), ALLMAN, 1872, Monog. Tubul. Hydroids, pp. 31, 212, 384, plate 18. Eleutheria dichotoma (non claparede), HAECKEL, 1879, Syst. der Medusen, p. 106. Eleutheria dichotoma, GRAEFFE, 1884, Arbeit, Zool. Inst. Wien, Bd. 5, p. 353. — HARTLAUB, 1886, Zool. Anzeiger, Bd. 9, p. 706, I fig. Also: Ibid., 1887, Bd. 10, p. 652; 1907, Nordisches Plankton, Nr. 12, p. 127, fign. 1 19, 120. — BEDOT, 1905, Revue Suisse de Zool., tome 13, p. 133 (literature cited to 1850). — MULLER, 1908, Zeit. fijr wissen. Zool., Bd. 89, pp. 34, 73, taf. 3, fign. 3-7 (origin and structure of eggs). This medusa is exceedingly variable, but the normal form may be briefly described as follows : Bell irregularly hemispherical, with its lower surface more or less 6-sided. 0.3 to 0.4 mm. wide. There is a ridge of large nettling warts extending around the margin. There are 6 ten- tacles at the ends of the 6 short radial-canals, and not irregularly arranged in reference to the radial-canals as in E. claparedii Hartlaub = E. dichotoma Claparede. A. \THOM Kill S.K KI.KI TIIKK1A. 95 Each tentacle bifurcates and is twice as long as the bell-diameter. The 2 terminal branches end one in an adhesive disk, and the other in a large, knob-like cluster of nettle-cells. These branches are not quite as long as the basal shaft of the tentacle itself. An abaxial ocellus is found at the base of each tentacle. The medusa is hermaphroditic, and the sexual products arc developed in an ectodermal brood-pouch above, but not connected with, the stomach. The cavity ol the brood-pouch is connected with the bell-cavity by means ot 6 simple, interradial openings which alternate with the 6 radial-canals. Sperm develops in the aboral, and ova in the oral ( lower) \\all of the brood-pouch. Medusa-buds are also produced upon the exumbrella side of the ring-canal, and this process is usually associated with the sexual reproduction. The terminal suckers of the ten- tacles are orange or yellowish-brown. Stomach and canals yellowish. This medusa is found clinging to green sea-weeds oft the Atlantic coasts of Belgium, England, and France, and is widely distributed in the Mediterranean. Graefte. 1884, found it to be common upon Ulvu from July to September at Trieste, Adriatic Sea. The budded medusse become sexually mature in 3 to 4 weeks. The planula larva creeps over the sea- weeds. Detailed descriptions are given by Ouatrefages and Allman, and the best modern account is that of Hartlaub, who discovered the remarkable character of the brood-pouch or ecto- dermal gonad. FIG. 48. — Eletithfriti difholiwa, after Hartlaub, in Xordischcs Plankton. The hydroid is Clavatella prolifera Hincks (see definition of the genus Eleutheria). Eleutheria dichotoma is apparently quite variable. The tentacles and radial-canals, al- though normally 6, may range from 4 to 8. Haeckel, 1879, p. 106, designates these aberrations as "subspecies, " and gives specific names to twelve of them, although a number of these should he credited to Eleutheria claparcJu Hartlaub and its variations. Hartlaub finds that the ova develop into planula larvae within the brood-sac before being set tree. Miiller, 1908, studied the origin and structure of the eggs of this medusa. The eggs are small, numerous, and oval in outline, not amcrhoid. There is no visible distinction between exoplasm and endoplasm. The ooplasma is a network of very fine fibers. There are num- erous small yolk-granules. Eleutheria claparedii Hartlaub. Eleuthrria elafaredii, HARTI.AI-K, 1889, Zonl. Anzeiger, Bil. 12, p. 665; 1907, Noriitscln^ Pl.mkt"ii. Nr. 12, p. 129. fii;. 121. EIrullifria dichotoma, CLAPAREDF., 1863, Bcobacht. Anat. und Entwicklungsges, \virhrllosrr Thicrr, p. 4. t.if. I, figs. 4-10. — SPAGNOLINI, 1876, Catalogo Acalefi Mediterraneo, p. 24, tav. 4, fig. 2. Bell 0.4 to 0.5 mm. wide, irregular in shape, usually more or less hemispherical (fig. 41; i. A ring of nettling warts on bell-margin. 8 to 10 tentacles, irregularly arranged in reference to the 4 to 6 radial-canals. A small abaxial ocellus at the base of each tentacle. The ten- tacles are 3.5 times as long as the bell-diameter, and they bifurcate at their extremities; one branch ends in an adhesive disk, and the other in a nettling knob. About (> or ~ medusa-buds are produced upon the subumbrella side of the ring-canal and project into the bell-cavity. 96 OF THE WORLD. This process of budding; is independent of the sexual reproduction. The terminal suckers ot the tentacles are orange. Found on Ulva in the Bay of Naples. Described in detail by Hartlaub. The structure of the reproductive sac is discussed in describing the character of the genus Eleutheria. Eleutheria vallentini Brown. Eleutheria vallentini, BROWNE, 1901, Annals and Mag. Nat. Hist., scr. 7, vol. 9, p. 279. Umbrella hemispherical, 3 mm. wide, 2 mm. high. 24 tentacles divided into two branches, the upper branch with clusters of nematocysts, the lower with a terminal sucker. "An ocellus on the extreme margin ot the umbrella opposite each tentacle." Stomach-tube conical and small. Mouth a plain round opening without lips. The gonads occupy "the whole of the upper part of the umbrella above the stomach." A single specimen was found by Vallentin at Fii;. 49. — Eleutheria claparetlii, after Hartlaub, in Nordisches Plankton. Stanley Harbor, Falkland Islands, and described by Browne. Color ( ?) Number of radial- canals ( ?) Brood-pouch ( ?) In the absence of a figure or a more detailed description it will probably be impossible to redetermine this form unless it be rediscovered in Stanley Harbor. Genus MNESTRA Krohn, 1853. Mnestra, KROHN, 1853, Archiv. fiir Naturges., Jahrg. 19, p. 278. — GUNTHER, 1903, Mittheil. Zool. Sta. Neapel., Bd. 16, p. 35. The type species is Mnestra parasites Krohn, from the Mediterranean. GENERIC CHARACTERS. Cladonemidae with 4 radial-canals and a ring-canal. No brood-sac above the stomach. 4 to o degenerate, hollow tentacles with a row of netting capsules along their aboral sides. \\ ith a ring of nettling cells around the margin and 4 linear tracts of nematocysts over the ANTIKiMI.IM S.K — MM.STKA. exumbrella, one above each of the 4 tentacle-bulbs. The throat of the medusa is blocked by a spongy mass of entoderm. There is a cup-like depression in the center of the exumbrella. This medusa attaches itself by its suctorial mouth to the throat of the opisthobranch mollusk, Phyllirhoe. It may lie derived from some Zanclea-like form \\bich has become degenerate through its sessile habits. It can not swim, yet it has well-developed circular muscles in the subumbrella and a distinct velum. Mnestra parasites Krohn. Mnf*i>, i /Hi'iifitef, KRIUIN, 1X53, Arclnv. Natures., Jalirg. 19, p. 178. — CLAIS, 1875, Vi-rli.indl. /.mil. Buun. Gi-M-ll., \Vu-n. Bd. 25, p. 9, taf. i. — HAF.C'KEL, 1880, Syst. dor MrduM-n, p. 653. — GUNTHKK, 1903, Mmhnl. Znol. Sta. Ni-a|vl, lid. id. p. 35, plates l, 3, 42 figs. Mncstrii parasitica, FEWKES, 1884, American Naturalist, vol. iS, p. 197, figs. 4, 5. 5' Fid. 50.- — Mnestra parasites, from Florida, after Kc\\kt*s, in Aincr. Natu- ralist, 1884. Fn.. 51. — Mnestra parasites^ after Giinthrr, in Mitth. Zool. Sta. Nc.ip Bell turned inside out, showing iiunit]i-|>.irt -, and cauti exumbrella to be cup-shaped. Medusa hat. 3 \vcll-»lc\r1f>pi-H\I:M \. 101 body of" the hydranth Is pale reddish and the perisarc bright yellowish-brown. The medusae are produced in spring and summer. Dujardin's, 1843, observations upon Cladonema niJintiun are the earlit-st in which the complete life-history ot' the alternation of generations between hydroid and medusa was actually observed. Cladonema perkinsii Mayer. Plate 9, fig. i . C.lailonema, sp., PERKINS, 1902, Johns Hopkins Uimersitv Circulars, vol. n. No. 1^5. p. 2^, ne,^. in ti-it. Cladonema per kin sii, MAVFR, 1904, Memoir- N.it. Sci. Brooklyn Inst. Arts ami SM .. vol. i , XL. i . p. i X, plate 4, fig. 35. — H*KT- LAi'B, 1907, Nonlisches Plankton, Nr. 12, p. i ;^, tit:, i±t>. Bell half-egg-shaped; less than 2 mm. in diameter, with thin, uniform walls. 8 lar<;e, stout, marginal tentacles. The inner and lateral parts of each of these tentacles bear 3 to 10 small, flexible cirri, which are besprinkled with wait-like clusters of nematocysts and termi- nate in a knob. 1 here is a large, cup-like, ectodermal ocellus upon the outer side of each main tentacle shaft near the bell-margin. The velum is large and shows circular striations. Manubrium large and spindle-shaped, with about n rounded, protruding pouches at its widest part. The mouth is surrounded by a circlet of 5 simple, short oral tentacles each terminating in a knob-like mass of nematocysts. 8 simple radial-canals, 45° apart, arise hum the stomach, and extend straight unvard the simple circular vessel. The manuhrium is thus 8-sided at its proximal end, 6-sided in the middle, and 5-sided at the mouth. The genital products develop in the ectoderm ot a large part ot the manubriurn and also in the hernia-like pouches. The ocelli are black and all other parts colorless. This species was discovered by Professor Perkins in Nassau Harbor, Bahamas, in July, 1902, upon the surface in shallow water at night. Cladonema mayeri Perkins. Plate 9, figs. 2 an, I -, . Cladonema, .., FKWKES, iSS^, Bull. Mus. Comp. Zool. at Harvard College, vol. 11, p. 87. Cladonema ma\eri, PKRKINS, 1906, Year Book of tile Carnegie Institution of Washington, No. 4, IIJCK. p. llS. — KjoS, Papers from Tort u gas I. ah. Carnegie In ^t. Washington, \ol. i , p. i ;(>, plate- i an, I 2. plate 4, figs. 2 t , 22. H\ ,!roul an, I medusa. Bell thin-walled, higher than a hemisphere, and with small, solid, apical projection; top rounded and dome-like, and total height about 2.5 mm. There are 9 marginal tentacles, one at the toot of each radial-canal. Each ot these tentacles has a large, spindle-shaped basal bulb, the entoderm of which contains a mass of white concretions. On the outer side of each basal bulb near the circular canal there is a deep reddish-brown, ectodermal pigment spot. The distal, inner side of each basal bulb gives rise to about 6 small tapering peduncles which terminate in small knob-like adhesive disks. These enable the medusa to cling to the sides or bottom of the aquarium. The main shaft of each tentacle extends outward from the spindle-shaped end of the basal bulb. It is umtorm, thread-like, and slender, and gives rise to 4 to 8 thread-like side branches each ot which, together with the central shaft, terminates in a knob-like cluster ot nematocvsts. There are 4 to 6 nematocyst-warts upon each side branch and a greater number upon the main shaft. Both the main shaft and the side brandies are highly contractile and can be expanded so as to become longer than the bell-height, or contracted into a close bunch. The velum is very wide and its orifice small. 6 radial-canals arise from the stomach, but every alternate canal bifurcates near its point ot origin, and thus () equally spaced canals reach the circular vessel. The manubrium normal!) extends to the level of the velar opening, but may contract somewhat at times, as is shown in our figure. The mouth is surrounded by <> simple oral tentacles, each of which terminates in a large nematocyst-knob. Near the middle of the stomach there is a circlet of 6 radially arranged, short, blunt, hernia-like projections. The genital products are developed in the ectoderm of the walls of the manubrium. The color is quite variable. The entoderm ot the basal bulbs ot tin- marginal tentacles is milky-yellow streaked with dark-brown pigment-granules, while the entoderm of the manubrium is milky-yellow or dull-milky ocher, streaked longitudinally in each of the ft radii by dark-brown, almost black, pigment-granules. The disposition and arrangement ot this pigment is highly variable. Perkins, iijoX, nives the most complete account ot this medusa and its hydroid. 102 MF.nrs.K UK TIIK WORLD. This medusa, together with its hydroid stage, was found in great numbers by Prof. Henry F. Perkins in the salt-water moat of Fort Jefferson, Tortugas, during the summer of 1905. The hydroid is a minute Stauridiu which grows upon algae. The same medusa was described by Fewkes, 1883, as being in association with Cassiopea at Fleming's Key, near Key West, Florida. Genus DENDRONEMA Haeckel, 1879. Dtmlronema, HAFCKEL, 1879, Syst. der Metlusen, p. MO. — GUNTHER, 1903, Mitth. Zool. Sta. Neapel, Bil. 16, p. 57. The only known form is Dendronema styludendron Haeckel, from the Canary Islands, Atlantic Ocean. GENERIC CHARACTERS. Cladonemidae with branched oral tentacles and branched marginal tentacles, the branches ending in nematocyst-knobs or adhesive disks, or both. With bifurcated radial- canals. Gonads in the stomach-wall. There is an apical cavity above the stomach, but we do not know whether this is a mere extension of the stomach itself, or a reproductive sac similar in anatomy to that of Eleutkena. Dendronema stylodendron Haeckel. ])?rnlionetiiti st \lrjiletidT on, HAVCKKL, 1879, Syst. iler Medusen, p. no, taf. 7, fi^. 8. Bell miter-shaped, with pointed conical apex. 9 mm. high, 6 mm. wide. Stomach spindle- shaped. There are apparently 4 radially placed oral tentacles each of which branches dichot- omously 6 to 7 times and terminates in (50 to 60) nematocyst-knobs in each quadrant. Haeckel's description is, however, vague upon this point. Haeckel states that there are 4 egg- shaped "gonads" on the 4 perradial sides of the stomach. These may, however, be homol- ogous with the protuberances seen in Cladonema ( ?) HaeckePs figure shows them distended with ova. 4 principal radial-canals, 90° apart, leave the stomach and bifurcate so that 8 vessels reach the ring-canal 45° apart. There are 8 marginal tentacles, one at the base of each radial-canal. There is an ectodermal abaxial ocellus at the base of each tentacle. Each ten- tacle gives off a stout, short branch on its inner (velar) side, .and this branch bifurcates twice and terminates in 4 nematocyst-bearing, knob-like "suckers," or adhesive organs. The main shaft of the tentacle also branches dichotomously many times and is besprinkled with nettling warts, and the ends terminate in large knobs. There is a spindle-shaped cavity in the apex of the bell, above the stomach, but its anatomical character is unknown. The mouth, stomach, apical cavity, and gonads are reddish-yellow. Tentacles, radial-canals, and ring-canal brown- ish-red. Ocelli black. This medusa was found by Haeckel in the Canary Islands, Atlantic Ocean, in February, 1867. Family OCEANIDjE, sens. Vanhoffen, 1891. OeeaniiLr (in part), ESCHSCHOLTZ, 1829, Syst. der Acalephcn, p. 96. — FORBES, 1848, British Naked-eyed Medusa-, p. 21.— GEGENBAUR, 1856, Zeit. fur wissen. Zool., Bd. 8, p. 219. Tiarid.e+ Margt'lidlp + Cannotidtf (in part), HAECKEL, 1879, Syst. der Medusen, pp. 40, 68, 1^6-159. Ocrnniiir, VANHOFFEN, 1891, Zool. Anzeiger, Bd. 14, p. 443. FAMILY CHARACTERS. Anthomedusa? with 4, or 4 pairs of, isolated gonads upon the interradial or adradial sides of the stomach. The marginal tentacles may arise singly or in clusters, but are neither branched nor feathered. The Oceanidae constitute the third family of the Anthomedusae, and they are more com plex and more highly differentiated than the simple and more primitive Codonidae. AXTHOMKlll S.K -OCEANID.S. HIM We distinguish three subfamilies ot" Oceanidae. 1. Tiarirue. Lips without oral tentacles. Simple unbranched radial-canals. Ten- tacles arise separately from the hell-margin and are not grouped in clusters. 2. Margelinti'. With oral tentacles. Simple, unhranched radial-canals. In some genera the marginal tentacles arise singly; in others they are grouped in clusters. 3. DenJrostaurtnte. Lips without oral tentacles. The radial-canals branch. Direct development ot the medusa trom the egg is unknown in this tamilv. The following genera are known to develop through Tubularian hydroids: Stomotoca, Turrn. Podocaryne, Stylactis, Bougainvillia, Neinopsts, Lizzia, and ftillia. Medusae are produced asexually upon the interradial sides of the manubrium in ('\tttis, PoJocoryne, Bougainvillia, and Rathkea, In some species of Bougainvillia the eggs undergo part of their development within the ectoderm of the parent medusa, and are discharged as well-developed planulae. In Ntobia the tentacle-bulbs develop into new medusae, and are set free one after another to repeat this process. In H illia and Prohoscidactyla, medusa-huds are produced upon hollow stolons which may arise from the corners ot the stomach at the points ot |uncture with the radial-canals, or from the places where the canals fork, as in P. flavicirrata, var. stolonifera, Maas. Haeckel, 1879, describes the gonads ot the Oceanidae as being penadial in position anil on the sides of the stomach in the same sectors with the radial-canals, but Vanhoffen, 1891 (Zool. Anzeiger, Bd. 14), showed that this is an error, for the gonads are almost universally adradial or interradial in position and alternate with the sectors of the radial-canals. The specialized conditions displayed by the medusae ot the Oceanidae, such as the corru- gated, folded gonads ot the Tiannae, the clustered marginal tentacles and the oral tentacles of the Margelmae, and the forked radial-canals and other peculiar structures in the Dendro- staurinae.all indicate that the Oceanidae are derived from simpler forms, such as the Codonidae. Indeed, the conditions seen in theOceanidae are largelytoreshadowed in the more differentiated Codonidae and in the Cladonemidae. In common with the Codonidae and Cladonemidae the Oceanidae are derived trom Tubularian hydroids. Subfamily TIARINjE Haeckel, 1879. (liemnd.r (in part), ESCHSC HOLTZ, 1829, Syst. tier Acalephen, p. <)(>. GK^NBACR, lNcf>, 7.ni. fiir uissrn. /mil., Hd. S,p. 219. \mleiffrtF (in part), LKSSON, 1X45, Hist. Nat. Zooph. Acal., p. 28}. Tjitridii-, HAF-CKRL, 1879, Syst. der Medusen, p. 40. Sfns. reslr,, drlomrrinthiu, VANHO? UK, 1891, Xool. Anzeiger, Bd. 14, p. 44V Tiiiriiiit, HARTLAUB, 1892, Nachrichten kgl. Gesell. Wissenschafl. Univ. Gottingen, pp. 19-22; 1907, Nordisihes 1'l.inkton, Nr. 12, p. 5. .SVfn. restr.t Tiurijcp, MAAS, 1904, Result. Camp. Sci. Prince de Monaco, fasc. iS, |>. ri. Tiilrin.r, VON LENDENPELDj |NS4, X.uol. An/fiytT, Bd. 7, p. 446. CHARACTERS OK THF. TIARIN/E. Anthomedusae with 4 lips, without oral tentacles. With 4 or more unbranched radial- canals and with simple, hollow, unhranched tentacles which are not grouped in clusters, but arise separately from the bell-margin. With interradial or adradial gonads forming swollen, corrugated regions in the walls of the stomach. The following table shows the genera of the Tiarinae. 1 . Tnhc PROTIARIDI : The outer surfaces of the four interradial gonads are smooth. Not corrugated or folded. There are 4 simple lips, 4 r.uii.d- canals, and a ring-canal, 4 or more tentacles. Proriara HAtcKEL, 1879. With 4 radial-canals and 4 radially situated marginal tentacles. 4 simple lips not com- plexly folded. Hydroid unknown. Hetrroliara MAAS, 1905. With 4 radial-canals, and 8 marginal tentacles. Ring-canal gives rise to interradial, blindly- ending, centripetal canals. Only species is H. anon\mn, MAAS, 1905, Craspedoten Medusen Siboga Expedition, Monog. lo, p. 19, taf. 3, figs. 19-21, Malay Archipelago. Hydroid unknown. 2. Tribe AMPHINEMIDI: With 2 long and numerous rudimentary tentacles. There are 4 radial-canals. Slomoloca L. AOASSIZ, 1862 = Amphincma + Stomoloca+ Codonorchis, HAICKII, 1^79. With two well-developed ten- tacles. Manubrium mav or may not be mounted upon a peduncle. Gonads corrugated, folded, swollen regions upon interradial or adradial sides of stomach. Dissontma HAECKEL, 1879. With 2 well-developed and numerous rudimentary tentacles. During their development gonads migrate outward from sides of stomach down the 4 radial-canals. 104 MKDT'S.K OF THE WOULD. V Tribe PAND.IIDI: With 4 or more well-developed tentacles. The gonails are interradial, corrugated, or folded ridges in the wall of the stomach 4 radial-canals. Pundta LESSON, 1843 (1837?). 4 interradial gonads in stomach-wall, not completely separated in the 4 principal radii. Hydntid unknown. Conis BRANDT, 1838. Ocelli borne upon ends of special, short clubs which arise from bases of tentacles. Hydroid unknown. Turris LESSON, i^^=Tiara, LESSON -4- Catablema, HAECKEL. With 4 interradial crescent-shaped gonads in the ecto- derm of the stomach-wall. Each crescent is composed of partially fused, swollen ridges. Hydroid: Clavttla ( ?), Carnpaniclava ; or Perigonimus ( r) 4. Tribe CAI.YCOPSIDI: With more than 4 simple, unbranched radial-canals. Adradial, transversely folded gonads. Cnhcopsis FEWKES, 1882. With 16 simple, separate, unbranched radial-canals, 4 radial, 4 interradial, 8 adradial. Haeckel, 1879, established the family Tiandae for Anthomedusa? with 4 wide, crenulated lips; with 4 separated or 8 cleft gonads in the stomach-wall; with 4 wide, hand-like radial- canals; and with simple, unbranched tentacles. Vanhoffen, 1891, showed that the gonads were interradial, not radial in position as was supposed to be the case by Haeckel; and in 1892 Hartlaub gave important details of the structure of the gonads, showing that Panden had simpler gonads than either Tiara or Turris. For example, he showed that the gonads of Pandea conica consist of 4 interradial, horseshoe- shaped, network-like, swollen regions in the ectoderm of the stomach-wall. The gonads of T urns cceca, however, consist not only in the interradial network, hut chiefly in a double row of fused longitudinal swellings in each interradial quadrant of the stomach. In Tiara pileata, on the other hand, we find none of these network-like gonads, but instead a horseshoe-shaped gonad in each interradial quadrant, the apex being upward and the sides of the horseshoe being made up of a series of laterally-fused, horizontal swellings. Maas, 1904, loc. cit., gives clear figures of these conditions and supports Hartlaub's observations. In the more complex and specialized Tiarinae, represented by the tribes Amphinemidi and Pandaeidi, the gonads are thrown into complex folds or corrugations, and the lips have become recurved, with folded edges. Vanhoffen concluded that Amplnnema and Codonorchls of Haeckel are equivalent to Stomotoca L. Agassiz; and in this I concur. He also maintained that Pandea Lesson was identical with Tiara Lesson, but in 1892 Hartlaub showed that the gonads of Pandea were quite different in structure from those of Tiara; and Maas, 1904, supports this conclusion. Maas, 1904, calls attention to the fact that there are no definite distinctions between Turns and Tiara. He shows that the gonads of Turris consist of 4 interradial horseshoes, the sides of each horseshoe being made up of partially fused, transverse, branched, ectodermal ridges and the upper apex of the horseshoe being composed of an open network of ridges. In Tiara the gonads are horseshoe-shaped, but commonly lack the network-like ridges. The transverse ridges do anastomose to some degree, however, in Tiara, so that a partial network is often found. See Maas, 1904, lor. at., plate 2, fig. II. Maas describes the gonads of Catablema Haeckel as horseshoe-shaped and composed of partially fused, vertical ridges. In the fully-grown medusa, however, I find that the ridges tend to become transverse, as in Turris or Tiara. Maas, 1904, retains the genus Catablema of Haeckel to include medusae resembling Turns or Tiara, but with blindly-ending, lateral diverticula upon their radial-canal and ring- canal. As a matter of fact these diverticula are highly variable in different individuals of the same species and are seen in a more or less well-developed condition in the majority of Tiarinae. I therefore believe that confusion will be avoided it we combine the genera Turris, Tiara, and Catablema to form a single genus. This should be called "Turris," for Lesson used this name on page 283 of his Hist. Zooph. Acal., and on page 17 of his "Prodrome," 1837 Tiara he defines later on page 286 of his "Histoire," 1843, and on page 20 of his " Prodrome, "1837. I propose, therefore, following the lead of Vanhoffen, Hartlaub, and Maas, to reduce the 13 genera of Tiarinae enumerated by Haeckel, 1879, to 8, as follows: Stomotoca, Modeeria, Protiara, Heterotiara, Pandea, Turns, Corns, and Calycopsis. The Tiarinae are widely distributed, but are abundant only along continental coasts, for in so far as is known, they arise by budding from Tubularian hydroids of the genera Pcngoni- nius, Clavula ( ?), and Campaniclava ( r). Asexual budding or direct development in the medusa-stage is unknown. ANTIKiMI Dl - E -I'lioTIAUA. ] Of) The medusae <>t the various genera of Tiarinae hear a close resemhlance one to another. Their hells are usually miter-shaped; ectodermal ocelli are often found upon their hollow ten- tacle-bulbs, and their radial-canals arc usually hroad and Hat, and often with more or less jagged outlines. All of" the tentacles arise from the lower edge of" the bell-margin when young, but as growth proceeds, the upper parts of" the basal bulbs of the older ones are crowded and forced a short distance up the sides of the bell, while the smaller tentacles still remain upon the lower edge of the hell-margin. 1 his gives the appearance of two rows of tentacles. Hartlaub demonstrated that the so-called mesenteries of I lacckel. 1X70,, arc only the wide. funnel-like origins of the radial-canals, where they communicate with the stomach-cavity. As Maas, 1904, has shown, the Tiarinae have given rise to the more specialized Bytho- tiandi, wherein the radial-canals have become branched, and the latter arc probably related to the \\illiadi. I he Iiarmas are themselves derived, probably, from Codonidae in which the originally ring-like goiuul has become radially separated, so that it lies only in intrn.uli.il positions on the wall of the stomach. They are thus, apparently, more highly specialized than the Codonidae. Cnl\; »f>m with its 16 simple, unbranched radial-canals may be regarded as a form intermediate between the Tiarinae and Bythotiaridi. The Tiarinae are distinguished from the Margehnae by the tact that oral tentacles are never found in the Tiarinae, but are present in the Margelm;e. Moreover, the tentacles of the Tiarinae arise singly from the bell-margin, and are not grouped in clusters as is frequently the case in the more specialized Margelinae. It seems not improbable that the Tiarinae and Margelinae have arisen independently of each other from the Codonidae. A decided difference between the Tiarinae and Margelmae is that in the former the entodermal cores of the tentacles are hollow, and in the Margelinae they are nearly, it" not wholly, solid. When present the ectodermal ocelli in the Tiarinae are on the untt'r sides of tin- tentacle-bulbs, whereas in the Margelinae they are on the inner (velar) sides Genus PROTIARA Haeckel, 1879. Carminrolhe btroe, SLABBER, 177?, Physikal. BHust., p. 64. Proliara, HAECKEL, 1879, Svst. ilrr MciluM-n, p. 46. HARC.ITT, 1902, Biological Bulletin, Boston, vol. 4, p. 17; )<)O4, Bull. I'. S. Bureau of Fisheries, vol. 24, p. 34. — LINKO, 190:, /.»< -1 . Xii/rim-r, J.ilirt,-. : ^, p. i (12. ( ? ) PlolorniJe, WAI, NCR, 18X5, \VirMlosrn des WIT.M-H Mo-res, BJ. i, p. 74. Halititirti, KFWKFS, 1882, Bull. Museum Conip. /mil. at Harvanl Collet;.-, M.|. >), p. J-M. V.\^i/ .in.) M^YJR, lS<|i), Hull. Museum Conip. Zool. at Harvard College, vol. 32, p. 160. GENERIC CHARACTERS. Tiarinae with 4 well-developed, radially situated tentacles with hollow, basal bulbs. \\ ith 4 longitudinal, swollen gonads on the 4 interradial sides fit the stomach. The outer surfaces of these gonads are smooth, not folded, nor corrugated, 1 he 4 lips are simple, not folded noi crenulated. Haeckel, 1^79, founded this genus for P. t)Proliara borea/is = Phtocnide borealis, Colorless variety, WAGNER, 1885, Wirbellosen des Weissen Meeres, Bd. I, p. 74, taf. 4, fign. I, 2. ( ?) (Svndictian ?) incerturn, LINKO, 1900, Travaui Soc.Imp.Nat.de St. Petersbourg, tome 29, p. 151, fig. l (this is possibly Sarsia flannnea ?). ( fyPlotocnidc incena, HARTLAUB, Nordisches Plankton, Nr. 12, p. 70, fig. 66. Bell 6 to 15 mm. high, 4 to 12 mm. wide. Egg-shaped, with very thick walls, which in the upper part of the bell are one-third to one-fourth as thick as the hell-height. There are a few scattered nettle-cells over the exumbrella, these being more numerous in young than in old specimens. 4 tentacles, each 4 to 5 times as long as the bell-height, with thick basal bulbs about one-sixth as wide as the greatest width of the bell. No ocelli. The shafts of the tentacles bear garland-like pads of nettle-cells. There are 4 straight, narrow radial-canals with smooth edges. The manubrium is short and even in mature medusae does not project beyond the velar opening. In young medusas it is conical, in mature individuals very wide, but it narrows greatly at the neck immediately above the mouth. The neck is tubular, and the mouth is encircled with nematocysts. There are 4 longitudinal, interradial, ectodermal gonads, which project widely outward in the upper portion of the manubrium, but do not extend to the mouth. The outer surfaces of the gonads are smooth. Linko, 1902, sectioned the manubrium and found that the entoderm forms 4 interradial partial septa which project inward in 4 longitudinal folds toward the axial center of the stomach, but their inner edges do not fuse. The cells of these septa are digestive and they serve apparently to increase the area of the stomach-wall. The bell is colorless. Manu- brium and tentacle-bulbs orange to yellow, radial-canals white. Common in Barents Sea, North of Russia, between 68° 54' and 70° 5' N. lat.; and 33° 3°' to 57° 38' l°ng- E- from Greenwich. Rare in harbors and fjords. (Syndiction?) incerturn, Linko, 1900, may possibly be identical with P. beroe. It has a bell 3 mm. high and somewhat more than 3 mm. wide. The walls are thick and there is a rounded, dome-like apex sharply set off from the bell itself. The exumbrella is besprinkled with quite regularly and widely spaced nematocysts. There are 4 thick, tapering tentacles about one-third to one-half as long as the bell-height. These have large, spherical, non- ocellated, basal bulbs. Velum well-developed. 4 straight, slender radial-canals. Stomach mounted upon a short, conical peduncle. The mouth does not reach the level of the velar opening. Mouth-opening round, without prominent lips. The gonad is figured as being much swollen above, tapering below, and encircling the stomach. It is not wholly clear from Linko's description whether there are 4 interradial gonads or only one encircling gonad, for he states that the medusa resembles P. borealis = (Syndictton boreale Birula) in some of its characters. Only about 10 very large eggs are produced by the female. The manubrium is yellow to orange, tentacle-bulbs red, and tentacles yellow. Other parts are colorless. Found in the White Sea, Northern Russia. It is probable that this form is a Sarsia, and is possibly S. flammea. See Hartlaub, 1903, 1907. There is, however, no peduncle in .V. flammea. Protiara borealis. Phtocnide borealis, WAGNER, 1885, Wirbellosen des Weissen Meeres, Bd. I, p. 74, taf. 4, fign. I, 2. Synilictyon boreale, BIRULA, 1896, Annuaire Musee Zool. Acad. Imp. Soc. St. Petersbourg, tome I, p. 336 (Russian). ( ?) Protiara h under the name of Gladde beroc, and the hydroid and young medusa were described by Van Beneden, 1867, as Dinema slabberi. Slabber's description is, however, so unsatisfactory that we can not be certain that this medusa is actually a Stomotoca, and can not accept it as the type of the genus. Stomotoca Jincma (Oceania Jincma} Peron and Lesueur may be taken as the type of the genus. The genus Saphenia Eschscholtz belongs to the Eucopidae. PLATE 10. Fig. i. Dissonrtna turnJa. Tortugas, Florida, May 13, 1905. An abnormal specimen lacking ocelli and marginal cirri. Fig. 2. Stoniotoi'a dinema, female. Agassiz Laboratory, Newport, Rhode Island, July, 1892. Fig. 3. Stomotoca dinema, male. Agassiz Laboratory, Newport, Rhode Island, September 13, 1896. Fig. 4. Stomotoca dinema, male. Agassiz Laboratory, Newport, Rhode Island, July, 1896. Figs. 5 and 6. Stomotoca rugosa. Agassiz Laboratory, Newport, Rhode Island, August 2 to 16, 1892. Drawn from life, by the author. PLATE 10 .\\THOMKin s K MMMOTOCA. 10!) FIG. 59. — Perigonimus "serpens," after Alltnan, in Ray Socjety, 1871-72. GENERIC CHARACTERS. Tiarina; with 2 long, diamcrrically opposed tentacles, and with more or less numerous, rudimentary tentacles. The basal bulbs of the long tentacles are hollow. The 4 interradial gonads are complexly folded and are found in the ectoderm of the sides of the stomach. The 4 radial-canals are broad and flat and there is a well-developed circular canal. The hydroid is Pengonimus. There are a numberof species of Pengonimus which probably produce tree f.S'/omo/o, M< >rt ><-.\. Ill margin. These lack ocelli. The 4 radial-canals are wide and flat. The boundaries of the radial-canals and of the ling-canal are often bluntly serrated. The manuhrium is flask- shaped; there is no peduncle and the 4 lips are cruciform, crenulated, and curve slightly upward. The ectoderm of the upper part of the manuhrium on both sides of the 4 ladial- canals is thrown into interradial folds or convolutions and the gonads are developed in this region. In the male the color of the manuhrium varies from intense green to translucent ocher- yellow or cream-color. The basal bulbs of the tentacles in the male vary from faint to deep purple. In the female the manubrium is usually translucent ocher-\ t -\\n\\ or cream-colored, but occasionally straw-colored or faintly green. The tentacle-bulbs of the female are usualU translucent milky or ocher, but occasionally one is found having faintly purple tentacle-bulbs. These sexually dimorphic color peculiarities are seen in the smallest and youngest medusae as well as in adults. In very young medusae the apical projection is small or absent. There are 2 tentacles and only 2 rudimentary tentacle-bulbs. This medusa is common at Newport, Rhode Island, from |ulv 15 to September. It is not common at Tortugas, Florida, and is not seen north of Cape Cod, Massachusetts. On October 28, 1907, I found two male medusae of this species oft" Mousehole, Mounts Bay, Cornwall, England. This species furnishes that which is probably the most remarkable instance of sexual dichromatism to be met with among the hydromedusae, the color differences affecting parts other than the gonads. The two males found off the coast of Cornwall, Kngland, were each 2.2 mm. high and similar in all respects to the typical American form; with intense green manuhrium and purple tentacle-bulbs, without ocelli. The bell-apex was solid and gelatinous. 1 believe that S. apicata of America. IS identical with S. Jlni'inn of Europe. The European medusa may have more rudimentary tentacle-bulbs, hut these are very variable in number in the Ameri- can form. Stomotoca atra Agassiz. Stottiotora atrn, AGASSI/, I... i862f Cont. Nat. Hist. U. S.f vol. 4, p. 347.- A<.-\SM/, A., iM>^. N^rth AIIMT. \<,il., p. it>^, figs. 271-27;. H^H-KH., 1X71), Sysl. ilcr Meilusen, p. 53. Bell 20 to 25 mm. high, 20 to 22 mm. wide. Bell-shaped, higher than a hemisphere. 2 long, highly contractile tentacles, and about 80 small rudimentary tentacle-bulbs. Stomach about half as long as the depth of the bell-cavity. Swollen, 4-sided, and mounted upon a peduncle. 4 lips. The gonads a re 8 ad radial, linear cross-foldings upon the sides of the Stomach, each gonad consisting of I 2 to 15 folds as in Turns. The mouth is dull yellow. Gonads dark- brown to almost black. Tentacles light-brown. Found by A. Agassiz in great numbers in Port Townsend, Washington, Pacific coast of the United States; from |une until September. Stomotoca octaedra. Plate 1 1, ti);s. <; ami f>. Cotlunorchis octnetlrus, HAFCKK.L, 1879, Syst. Jrr MrtliiM-n. p. 51. Sloniolocn austrtilis, MAYKR, 1900, Bull. Mus. (.'nrn|'. /.mil. .it Harvard College, vol. 37, p. 32, plate I, lii;. i; lintl., 1904, Mrin. Nat. Sci. Brooklvn Inst. Museum, vol. i, p. 9, platr i, fig. 9. The following description is derived from studies of specimens found in the Baham.is. and at Tortugas, Florida. Immature nirJ/isn (plate 11, fig. 6). — Bell about 2.5 mm. high and with well-developed, sharp-pointed, apical projection upon aboral side. Bell-walls thin.' There are 2 radially situated, diametrically opposed tentacles, each about as long as the bell-height and with long hollow, tapering basal bulbs. There is a single, ectodermal, orange-colored ocellus upon the outer side of each tentacle-bulb near its point of origin from the umbrella. In addition to the 2 long tentacles there are 2 short, rudimentary tentacle-bulbs go0 from the long tentacles. Each of these rudimentary tentacle-bulbs has an ectodermal, orange-colored ocellus upon its outer side, and there are 4 other ocelli upon the bell-margin in interradial positions. There are thus 8 ocelli in all, 4 on the tentacle-bulbs and 4 interradial ones on the bell-margin. 'I he 112 MKDUS.E OF THK WOULD. velum is well developed. There are 4 straight-edged, wide radial-canals and a broad circular vessel. The manubrium is urn-shaped, quite wide, and with 4 cruciform, recurved lips. The mouth is at a point about half-way between the inner apex of the bell-cavity and the velar opening. The gonads are found in complexly folded regions upon the 4 interradial sides of the stomach. The manubrium and tentacle-bulbs are yellow or greenish-yellow. The ento- dermal core of the stomach is often orange. When about I mm. high (plate 1 1, fig. 5) the bell has a small apical projection. There are 2 large tentacles and 2 rudimentary tentacle-bulbs, each with an orange ocellus. There are no other ocelli upon the bell-margin. The manubrium is slender and urn-shaped, without gonads and with 4 simple, cruciform lips. The young of this medusa are common at Tortugas, Florida, and in the Bahamas through- out the summer. Although the medusa has usually but 2 long tentacles, occasionally one is seen with 4 long, equally developed, radially situated tentacles. The mature medusa has not been seen and we must remain in doubt concerning its generic position, for it may be a young Turn's. The presence of ocelli upon the tentacle-bulbs distinguishes it from all other Ameri- can species of Stornotoca and is a character commonly seen in Turns. I believe this medusa to be identical with Haeckel's " Codonorchis octaedrus," which he obtained offthe Atlantic coast of France. Haeckel states that this medusa had 2 well-developed tentacles and 10 tentacle-bulbs (2 perradial and 8 adradial). He described the ocelli as brownish-red. Apparently he found but a single specimen and the interradial tentacle-bulbs may have failed to develop. His medusa is described as having folded gonads, and is said to be 4 mm. high and 2.5 wide. Stomotoca rugosa Mayer. Plate 10, figs. 5 and 6; plate 11, figs, i and 2. Slomoloca afirala, FEWKF.S, 1881, Bull. Mus. Comp. Zool. at Harvard College, vol. 8, p. 152, plate 2, figs, i, 4, 9.— HARC.ITT, 1901, American Naturalist, vol. 35, p. 581, fig. 40; 1904, Bull. U. S. Bureau of Fisheries, vol. 24, p. 35, i fig. (errone- ously labeled Stomotoca apicata, female). — RITTENHOUSE, 1907, Proc. Boston Soc. Nat. Hist., vol. 33, pp. 440, 445, 452, 456 (embryology). Stomotoca rugosa, MAYER, 1900, Bull. Mus. Comp. Zool. at Harvard College, vol. 37, p. 4, plate 2, fig. 5; Ihitl., p. 32. Amphinema u[titatuin, BROOKS, 1883, Studies Johns Hopkins Biol. Lab., vol. 2, p. 473. Bell 5 mm. high and 3 mm. broad. Solid, apical projection, in some individuals short and blunt, in others long and slender. Bell-walls of moderate thickness, and bell itself, exclusive of the apical projection, somewhat higher than a hemisphere, with relatively vertical, straight sides. There are 2 long, diametrically opposed tentacles, which are of equal length, and when stretched are fully ten times as long as the bell-height. They are, however, highly contractile and may become not more than one-tenth as long as when fully expanded. The basal bulbs of these long tentacles are large, hollow, and tapering and there are no ocelli. In addition to the 2 long tentacles there are 14 small, permanently rudimentary tentacles, 2 at the bases of 2 of the radial-canals and 3 in each interradial quadrant. These lack ocelli. The velum is well developed. There are 4 wide radial-canals and a ring-canal, all with jagged edges. The manubrium is quadratic and flask-shaped and the mouth in old medusae is about at the level of the velar opening. The mouth is cruciform and there are 4 prominent, recurved, crenulated lips. The mature sexual products are found in the ectoderm of the adradial walls of the stomach on both sides of the places of entrance of each of the 4 radial- canals where the surface is thrown into 8 series of complex folds and ridges, a double ridge of folds in each interradius. The gelatinous substance of the bell is transparent, but the entoderm of the tentacle-bulbs and stomach is brick-red, often streaked with sooty brown. The radial and circular canals are faint red in color. Specimens from Tortugas, Florida, often show black streaks through the brick-red color of the stomach and tentacle-bulbs, and medusae which have been confined in aquaria for some days often become wholly black in these parts. Hydrotd and \onng medusa. — Professor W. K. Brooks, 1885, describes the hydroid. It is a Pi-rigfjniiniis, very much like P. niiniitiis Allman, 1871 (Monog. Tubularian Hydroids, p. 324, plate xi, figs. 4 -6). It was found at Beaufort, North Carolina, growing upon the lower ANTHOMKIH'S.K— STOMOTOfA. 113 surface of the shells of Limulus, fastened to the sand-tubes of Sabfllarin. The stems are simple and unbranched and are only about 0.2 mm. in height. They are covered for about two- thirds of their length by a delicate, closely-adherent film of perisarc to which foreign particles become attached. The stomach occupies about one-fourth or one-fifth of the length of the stem from which it is separated by a slight constriction. Each polypite has 10 tentacles which point alternately backwards and forwards, those pointing forwards being a little longer than the others. The medusae are attached by very short peduncles to the sides of the stems. When the medusa is set free it is about 0.5 mm. in height and there is no trace of the apical projection, which develops in about eight days. In an abnormal individual medusa of this species found at Newport, Rhode Island, in July, 1892, there were 4 long tentacles, i at the base of each of the 4 radial-canals. This medusa was maintained alive in an aquarium for more than a month. When first found it had only 2 long tentacles which were diametrically opposite one another at the bases of i of the radial-canals. The other 2 tentacles developed later, after the first pair had attained their full length. The medusa had then 4 radially placed tentacles and 12 rudimentary tentacle-buds. This variation is interesting, as it illustrates the close relationship between Stiiniutrnu and Turns. Stomotoca ruorjsa is common on the southern coast of New England in summer. It is found all along the coast to southern Florida, but is not very common at Tortugas or among tin- Bahama Islands. It has never been seen north of Cape Cod, Massachusetts. Rittenhouse, 1907, finds that the eggs of this medusa are laid between 5'' to 5'' 30"' in the morning. The egg is chalky-white. The entoderm is formed by cellular ingression. The planula settles down upon its side and becomes a branched hydrorhi/a from which the p<>!\ •- piles bud out. Stomotoca pterophylla Haeckel. Plate 2<), figs. 5 to ^; pl.Ue 30, fig. 7. Xtomotoca ptfroplnlla, HAKCKF.I., 1879, Syst. der Medusen, p. 52, taf. 4, fig. 10. Xiumolorti persphyHa, F I:\VKKS, |SX<), Report Comrmss. Fish and Fisheries for 1X86, p. 524. Adult medusa. — Bell conical, with widely flaring sides and small, sharply-pointed apical projection. It is about 20 to jo mm. in diameter and 10 to 12 mm. in height. The gelatinous substance is very thick at the aboral pole, but becomes thin at the bell-margin. There are 2 long, tapering, marginal tentacles which are situated at the bases of 2 of the radial-canals, 1 80° apart. When expanded these tentacles are full}- 10 times longer than the bell-diameter. In addition to the long tentacles, there are about 60 to 80 small rudimentary tentacle-bulbs, 15 to 20 in each quadrant. The 4 radial-canals are wide, ribbon-like, and flat, with smooth, simple, outer edges. The ring-canal is narrow and its upper edge is smooth. There is a very wide, conical peduncle which extends about to the level ot the velar opening. The gastric part of the manubi mm is large and swollen and lies mainly outside ot the bell-cavity. There are 4 promi- nent, complexly crenulated, lanceolate lips. The gonads occupy 8 adradially situated, longitu- dinal swellings upon the sides ot the stomach (plate 29, fig. 4). Each gonad consists ot a io\\ of swollen, leaf-like ridges which trend in a transverse direction. The stomach and tentacle- bulbs are brown. Radial-canals milky. There are no ectodermal ocelli. This species is found in the West Indies and the warmer parts of the Gulf Stream. I found many specimens among the Bahamas and at the Tortugas during the spring and early summer ot 1907. It is closely related to Stomotoca Jivisa, described by Maas, from the west coast of Mexico (Mem. Mus. Comp. Zool. at Harvard College, vol. 23, p. n, tat. i. tigs, i ilii'n,-llii, of the- coast <>l Australia. GENERIC CHARACTERS. Tiarinas with two hollow, diametrically opposite tentacles. The gonads extend from the manubrium outward along the canals. Without marginal sense-clubs. Cirri aie some- times present. With abaxial, ectodennal ocelli upon the bases ot the tentacles. Rigelow, 1408, finds that the adradial gonads begin to develop upon the sides of the manubrium and that afterwards they extend outward over the radial-canals. The hollow tentacles, abaxial ectodermal ocelli, rudimentary tentacle-bulbs, and hollow bell-apeK are all characteristic of the Tiarinae., and it appears that this genus must be removed trom the Thaumantiad;e, in which Haeckel placed it. J)is.friiii-niii bears the same relation to St»in;\w,'M w<; niplifntlla, HAFI KKI, 1879, Svst. tier Mcduscn, p. 126, t:tf. 8, rl^. }. Bell pyriform, with thick, solid apex and thin, bulging sides. 6mm. high, 4 mm. uulc. 2 well-developed tentacles, several times as long as the bell-height. These tentacles have large, swollen, conical basal bulbs. There are 2 rudimentary tenta'cle-bulbs yo° apart trom the long tentacles. There is an abaxial (ectodermal ?) "ocellus" ot large si/e upon each ot the 4 tentacle-bulbs. There are no marginal clubs, cirri, or other appendages. The velum is well-developed and there are 4 straight, narrow radial-canals and a ring- canal. The manubrium is cylindrical, half as long as the depth of the bell-cavity and pro- vided with 4 short, crinkled lips. The 4 folded, spindle-shaped »onads are developed upon the middle three-fourths of the radial-canals. Color ( ?) Coast ot Australia. (See tig. ' Ill) MEDUS.E OF THE WORLD. Dissonema turrida Mayer. Plate 10, fig. l; plate 22, fig. I. Dissonema turriJa, MAYER, 1900, Bull. Mus. Comp. Zool. at Harvard College, vol. 37, p. 44, plate 2, figs. 3, 4; 1904, Mem. Nat. Sci. Brooklyn Institute Museum, vol. i, p. 8, plate 2, fig. 10. Adult medusa. — Bell bluntly cone-shaped with a hollow apical projection. It is 4 to 7 mm. high and the side walls are thin and flexible. There are 2 long, hollow, gradually tapering tentacles which are quite contractile, but when expanded are 3 to 4 times as long as the bell-height. Each of these tentacles has a minute, red ocellus in the ectoderm of its outer side near the bell-margin. In addition to the two large tentacles there are 12 to 14 small, solid cirri which arise separately, at equal intervals, from the bell-margin. Each cirrus has a red ocellus in the ecto- derm of its outer (abaxial) side at the bell- margin. The velum is well developed. The circular vessel is narrow, but the 4 radial-canals are broad, and the 4 convo- luted, bag-like gonads occupy three-quar- ters of their length and also lie upon the adradial sides of the manubrium. In the female each gonad contains 4 to 7 large eggs which project prominently over the surface of the organ. The manubrium is pyritorm and the mouth projects beyond the velar opening. The stomach-walls are thin and flexible, and the mouth is surrounded by large recurved lips with crinkled edges. 1 he entoderm of the manubrium and tentacles is a delicate green and the genital organs and circular canal are tinged with green or pink. The ocelli are red. In young medusae there are but 2 large tentacles and 2 cirri. There are 8 ocelli. The 2 long tentacles have tapering, hollow basal bulbs, but their main shafts are at first solid, though later they become hollow. This medusa is common on the surface in the Bahamas and at Tortugas, Florida, in summer. Dr. H. B. Bigelow shows as a result of sectioning the medusa of Dissonema that the gonads begin to develop upon the adradial sides of the manubrium and later extend outward down the radial-canals. This fact, taken in connection with the abaxial ectodermal ocelli, the hollow tentacles, bell-apex, rudi- mentary tentacles and general form of the medusa, make it evident that Dissonema is one of the Tiarinne. Genus PANDEA Lesson, 1843. Pan/tea, LESSON, 1837, Prodrom. Monog. Meduses, No. 22 (not published); 1843, Hist. Zooph. Acal., p. 288. — ACASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 347. Pantlepa, HAECKEL, 1879, Syst. der Medusen, p. 53. Pandra, AGASSIZ and MAYER, 1899, Bull. Mus. Comp. Zool. at Harvard College, vol. 32, p. 160. — HARTI.AI-B, 1892, Nachricht. kgl. Gesell. Wissenschaft. Univ. Gottingen, p. 21. — MAAS, 1904, Result. Camp. Sci. Prince de Monaco, fasc. 28, p. 15. Diantfa, Quov ET GAIMARD, 1827, Annal. des Sci. Naturelles, tome 10, plate 6. .\'on Dianefa, LAMARCK, 1816, Hist. Anim. sans Vert., tome 2, p. 505. Pandja, ZOJA, 1892, Boll. Sc. Paira, Anno 1891, Nos. 3, 4, 3 pp.; 1892, Annals and Mag. Nat. Hist., ser. 6, vol. 9, p. 409. (Deniiroclam dohrnii gives rise to a medusa resembling Pandea ?) Fin. 62. — Dissonema saphenella, after Haeckel, 1879. .\\THilMKDCS.E— r.\\T)K\. 11; The type species of PanJea is P. cnnlca Lesson, 1843. This medusa was previously described by Ouoy and Gaimard (1827, Annal. Sci. Nat., torn. 10, p. 182, plate 6) under the name Diantea conica. It is found in the Mediterranean. Haeckel introduced the spelling " PanJ(ta," although Lesson's original spelling is PanJea. The genus "Diantea" was founded by Lamarck (1816, Hist. Anim. sans Vert., torn. 2, p. 505), the type species being Diancea tneJra, a medusa which had been previously described by Pt-ron under the generic name of Lymnorea. Lamarck's genus Duimta also included various species of Geryonta, Oceania, Pelagia, and Mfdusa of previous authors, and is so hopelessly involved that in my opinion it must be dropped. GENERIC CHARACTERS. Tiarinae with 4 or more well-developed, marginal tentacles. There are 4 interradial, genital ridges in the ectodermal wall of the stomach, but these gonads are only imperfectly separated in the 4 principal radii; so that the stomach is completely encircled by the genital organs, which are, however, better developed in the interradii than in the principal radii. DenJroclava is possibly the hydroid of some species of PnnJea, Coins, or Turn's-, but the mature medusa is unknown. When set free the medusa of DenJroclava dohrnii (Weismann, 1883, pp. 26, 216, taf. 12, fign. 6-9) has 8 marginal tentacles, 4 radial-canals, and a manubrium with 4 band-like gonads i<;. 6j. — Pandeei conica. A. Side view of half-grown medusa. Bell 13 mm. high. Gonads interradial. H. Manubrium of mature medusa, with bell 21 mm. high. Gonads continent, surrounding stomach. C. Manubrium of young medusa, showing interradial gonads. Bell (> nun. lir\;h. l-'rom lit- . I'. the author. Zoological Station, Naples. Winter of 11)07-08. on its interradial sides. The sexual cells originate in the ectoderm of the manubrium of the medusa-bud and develop in the ectoderm of the free-swimming medusa, without wandering from their place of origin. The hydroid of DenJroclava dohrnii was found by Weismann at Naples in the summer of 1881, attached to a stock of Isis which was dredged from a depth ot 35 to 40 fathoms. The stems are about 35 mm. high and arise from a short, creeping hydro- rhiza, which together with the stems is covered by a smooth, horny perisarc. The main stems 118 MKDUS.E OF THE WOULD. give rise to alternate side branches. The hydranths are cluh-shaped and bear 12 to 20 short, filiform tentacles, scattered over their whole sides. The medusa-buds arise singly from the side branches close under the neck of the lateral hydranths. Pictet, 1893, found a very similar or identical hydroid at Amboina, Malay Archipelago. The principal references to this clava- like hydroid are as follows: DenJroflava Johrnii, WEISMANN, 1893, Entstehung Sexualzellen bei Hydromedusen, Jena, pp. 26, 215, taf. 12, fign. 6-9. — DU PLESSIS, 1888, Reeueil Zool. Suisse, tome 4, p. 531 (from Villefranclie). DenJroclava dohrni, PICTET, 1893, Revue Suisse Zool., tome I, p. 6, plate I, figs. I, 2 (from Amboina). It does not seem probable that Dcndroclava dohrni produces a Pandea-like medusa, for it is well established by Brooks that Tumtopsis nutricula comes from a DenJroclava hydroid. Pandea conica Lesson. DianR, iX<)!. at Harvard C'"llrt;i\ vol. ;2, p. i(>o. M\vtR, 1900, Bull. Mus. Comp. Zocil. at Harvard College, vol. 37, p. 34, plate i, fig. i. Pandea, s/>., LoBiANCo, 1903, Mitth. Zoolog. Sta. Neapel, Bil. 16, p. 217, lav. 7, fig. i. Bell pear-shaped and 7.5 mm. high, with moderately thick walls. There are about 32 tentacles. 8 to 12 of these are about 3 times as long as the bell-height and 24 are small and rudimentary. The long tentacles are all of equal length. Their basal bulbs are long, tapering, and hollow. There are i to 3 rudi- mentary tentacle-bulbs between each successive pair of long ten- tacles. There are about 32 ectodermal, purple ocelli, one on tin- outer side of each tentacle-bulb. The velum is well developed. The manubrium is flask-shaped and quadratic in cross-section. The outer surfaces of the adradial gonads are smooth and with- out corrugations (plate n, fig. 7). The mouth is at the extrem- ity of a well-developed neck and is at about the level of the velar opening. There are 4 large, slightly recurved lips with smooth, simple edges. There are 4 straight, narrow radial-canals and a broad circular vessel. The entoderm of the manubrium and ten- tacle-bulbs is delicate pink and in some specimens a green streak extends along the outer surface of the entodermal lining of the radial-canals. This medusa is common at the Tortugas, Florida, and among the Bahamas throughout the summer. An appar- ently identical species is found at Suva in the Fiji Islands, South Pacific, although the Pacific medusa is not so highly colored. A closely related, if not identical, medusa is described by Lobianco, 1903, from two specimens drawn from depths of 500 to 600 fathoms near Capri, Bay of Naples, Italy. Dr. Lobianco kindly permitted me to studythese specimens. The bell is 1 1 mm. high, 7 mm. wide; thick-walled, with dome-like apex. There are 12 to 13 long tentacles, 4 to 5 times as long as the bell-height. These have long, hollow, tapering basal bulbs, each with an abaxial, dark-red ectodermal ocellus. In addition to the long tentacles there are about 24 to 36 very short rudimentary marginal tentacles, each with an abaxial ocellus. The 4 radial-canals are quite wide and with slightly jagged outlines. The manubrium is half as long as the depth of the bell-cavity. The 4 complexly folded lips are at the end of a well-developed neck. The outer surfaces of the adradial gonads are smooth. The entoderm is strawberry-pink. I can not separate this medusa from Pandea violacea of Tortugas, Florida, some specimens of which are fully as pink in color as is the one shown in Lobianco's figure. FK;. 64. — Pandra vtolacea, after Lobianco, Mitth. Zool. Sta. Neapel, 1903. Pandea maasi. Tiara, j/)., MAAS, 1904, Result. Camp. Sci. Prince dc Monaco, fasc. 28, p. 13, plate 2, fig. M. Bell 10 to 13 mm. high and only about half as wide as high, with a smooth exumbrella surface. Bell-walls quite thick, with an evenly rounded apex, without an apical pro]i-ctmn. 4 thick, hollow tentacles at the bases of the 4 radial-canals. These have large, swollen basal bulbs, but no ocelli were observed. The tentacles are about as long as the bell-height and 120 MEDUS.E OF THE WOULD. their shafts are of about uniform width throughout, the outer ends being very blunt, not taper- ing. There are no other tentacles or marginal appendages. The 4 radial-canals and the ring- canal are simple, narrow, and straight-edged; without glandular diverticula. The stomach is wide and barrel-shaped to cylindrical and is about three-fourths as long as the depth of the bell-cavity. There is no peduncle and the 4 radial-canals run directly into the stomach without enlarging as they approach its base. The mouth is well developed, but the lips are simple, without the foldings commonly seen in other Tiarinae. The gonad is developed as an open network of more or less transverse folds over the ecto- dermal wall of the stomach, excepting only the neighborhood of the mouth. The gonad is not distinctly separated into 4 interradial parts, but is more or less fused over the perradial lines, thus encircling the stomach very much as in medusae of the Codonidae or in Pandca con i en. The entoderm is yellow, the gonads being deep in color and the tentacles lighter. Other parts are transparent. Found by the Prince of Monaco at Bear Island, between Norway and Spitsbergen, in July, 1898. It is well figured and described by Maas, 1904. Hartlaub, 1907, considers this medusa to be identical with Sarsia flammea Hartlaub. The general proportions of the two medusae appear to be much alike, but the details of structure of the gonads and the color of P. maasi appear to distinguish it from other medusae. Genus TURRIS Lesson, 1843, sens, amend. Turr'n+Tiara (in part), LESSON, 1837, Prodrom. Monog. Meduses, Nos. 17, 20 (not published); 1843, Hist. Zooph. Acal., pp. 283, 286. Turris + Oceania (in part), FORBES, 1848, British Naked-eyed Medusae, pp. 21, 26. Turrh+ Tiara, AGASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, pp. 346, 347. — HARTLAUB, 1892, Nachricht. kgl. Gescll. Wissenschaft. Univ. Gottingen, pp. 20, 22. Turris, AGASSIZ, A., 1865, North Amer. Acal., p. 164. Tiara+ Turris+ Catablema, HAECKEL, 1879, Syst. der Medusen, pp. 56, 60, 62. Turris, FEWKES, 1881, Bull. Mus. Comp. Zoo], at Harvard College, vol. 8, p. 147. Tiara, WAGNER, 1885, Wirbellosen des Weissen Meeres, p. 78. — MAAS, 1905, Craspedoten Medusen der Siboqa Expedition, Monoe. 10, p. 14. — BOVERI, 1890, Jena. Zeit. Naturw., Bd. 24, p. 339. (The egg gives rise to 2 polar globules.) Cu1ablema-\- Turris + Tiara, VANHOFFEN, 1891, Zool. Anzeiger, Bd. 14, p. 444. Catablema+ Tiara+ Turris, MAAS, 1904, Result. Camp. Sci. Prince de Monaco, fasc. 28, pp. 12, 15, 16. GENERIC CHARACTERS. Tiannae with 4 or more marginal tentacles. With 4 interradial horseshoe-shaped gonads in the stomach-wall. Each horseshoe composed of partially fused swollen ridges. Lesson, 1843, describes three medusae under the name Turns, only one of which belongs to the genus as we define it. This one is Turns neglecta of the north Atlantic coasts of Europe. The name Tiara was also proposed by Lesson, 1843, and is used to describe a medusa which was first observed by Forskal, 1775, under the name Medusa pileata. It is found off the Atlantic coast of Europe and in the Mediterranean. I use Turris as equivalent to Turris Lesson + Tiara Lesson + Catablema Haeckel. Haeckel, 1879, p. 62, establishes Catablema for a Greenland medusa which he calls Catablema campanula. Maas, 1904, who embodies the results of the studies of Vanhbffen, Hartlaub, and himself, defines Turns as having horseshoe-shaped interradial gonads, the sides of the horseshoe being made up of partially fused, transverse ridges while the arch connecting the two sides is composed of an irregular network of ridges. In Tiara the network is lacking, the entire horseshoe being composed of more or less transverse ridges. The ridges do, however, anas- tomose to some extent, so that an imperfect, partial network may be formed. Catablema he distinguishes by the jagged edges of its radial-canals and circular vessel. However, medusa; of Turns and Tiara often display lagged edges upon their canals, and this character is very variable and subject to much individual irregularity in development. In the young medusa of Catablema the ridges forming its interradial horseshoe-shaped gonads tend more or less longitudinally, but in later development they come to he almost transversely as in Turns or Tiara. In order to terminate the confusion that has been introduced by these intergrading and too precise criteria for distinguishing the genera Turris, Tiara, and Catahlrma, I propose to unite them all under one genus and call it Turns, the name first used by Lesson to dis- tinguish any of these medusae. ANTHOMKUUS.E — '1THUIS. Tubular Synopsis of the Species of Turris. 121 T. papua Lesson. T.rotunda = Tiara rotunda Haeckel.* T.prismatica = Tiara prismatica Maas.f T.reticulata Haeckel. T. vesicaria A. Agassiz. Size of bell in mm. 28 high, 14 wide. Pointed apex. 20 high, 20 wide. Cubical. 20 high, 12 wide. 12 high, 10 wide. 25 high, 12 wide. Number of tenta- cles. 8 to 32 8 12 to 1 6 16 16 long, 48 short. Ectodcrmal, ab- Present. Prcbcnt. ? Present. Present. axial ocelli on tentacle-bulbs. Character of edges Serrated. Smooth. Serrated. Smooth. Jagged. Character of gonads. 4 interradial horsc- shoes of complex, mainly transverse swellings which anastomose to some extent. 4 pairs of adradial groups of cross- folds. As in T. pilcMta. 8 separate triangular areas in adradii of stomach, with complex anasto- mosing ridges. Swollen, transverse, papilliform, anastomosing folds forming net- work in 8 adradii of stomach. Color. Tentacle-bulbs an.l Tentacle-bulbE] ? ? Stomach and ten- stomach pink to dark-red. Gonads pink to dark- brownish-yellow. stomach, and gonads carmine. Radial-canals and ring-canal yellow. tacle-bulbs cin- namon-brown. Gonads darker. ens? •(•Hydroid: Clavula gossei Wright. PLATE 13. Fig. i. Protiara formosn, mature medusa. Tortugas, Florida, May 21, 1907. Oral view of female. Fig. 2. Protiara forniosa. One of the marginal cirri showing the chordate entodermal cells. Figs. 3 to 5. Podocoryiif fulgnraiis. Agassiz Laboratory, Newport, Rhode Island, September, 1892. Fig. 6. Turns pileata, young medusa. Agassiz Laboratory, Newport, Rhode Island, September 25, 1896. Fig. 7. Turris vesicaria, mature medusa. Eastport, Maine, August, 1897. Drawn from life, by the author. PLATE 13 . ANTHOMEDU8/E— TDRRI8. 123 Bell 4 to 6 mm. high, 5 to 4 mm. wide. Globular or with a conical apex and bulging sides; margin somewhat constricted. 60 to 70 short, crowded tentacles, shorter than the bell-height, with abaxial ocelli. Stomach wide, cruciform in cross-section, and one-half to two-thirds as long as the depth of the bell-cavity. 4 simple lanceolate lips, not complexly tolded. Gonads as in T. pilrtitu. Entoderm of stomach and tentacle-bulbs reddish-brown to rich purple. Found or!" the British coasts. The hydroid was obtained by Grosse and Wright, who reared it from the egg. The planula is bright crimson. The hydranths are club-shaped and only about 2.5 mm. high. They arise singly at intervals from a creeping filiform h\dm- rhiza and have 12 or more scattered, filiform tentacles. The Fn.. 65. Hvdroid of ' Hincks, Zoophytes. rj negfecta, after hydrocaulus and hvdrorhiza are invested by a perisaic. Hincks, in British Hvdroid .; . Hydranths bright crimson. Turris pileata. Plate n, fig. 4; plate 13, fig. d. Medusa pileata, FORSKAL, 1775, Descriptions Animal., p. no; 1776, Icones rerum naturalium, plan- 33, fig. I). ania pileata+ P. Lesueur, PERON ET LESUEUR, 1809, Ann. du Museum d'Hist. Nat., tome 14, p. nia (Charvbdea) pisifera, OKEN, 1815, Lehrbuch iler Naturges., Tril 3, p. 125. ania ampitHacea, SARS, 1835, Beskriv og Jagttagelser, p. 22, plate 4, fig. fta-f. ra f>,ifia/ii+T. sarsii, LESSON, 1843, Hist. Zooph. AcaL, p. 287. ania turrita+0. octona+O. episcopates, FORBES, 1848, British Naked-eyed Mediis.r, pp. 27, 28, plate 2, figs. 1-3. ania coccinea, LEI'CKART, 1856, Archiv. fur Naturges., Jahrg. 22, p. 24. alidium arnpullaceum + Tiara pileata, A<;ASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, pp. 352, 347. 0 0: T Or Or Ph Tiara smara^dina, HAECKEL, 1864, Jena. Zeit. fiir Naturvv., Bd. i, p. 336. Oceania pileata, SPAT.NOLINI, 1876, Catalogo Acalefi Mediterraneo, p. 21, tav. 3, fig. i, 2. Tiata pileata, HAECKEL, 1879, Syst. der Medusen, p. 58, taf. 3, fign. 6-8.— HAMANN, 1883, Zeit. fiir wissen. Zoo!., Bd. 38, p. 426, taf. 23, fign. 16-20 (development of the planula larva).— METSCHNIKOFF, E., 1886, Embryol. Sludien an Medusen, pp. 29, 48, etc., taf. l, fign. 1-17. — HARTLAUB, 1894, Wissen. Meeresuntersuch. Komni. Mrrrr Ku-l, Helgoland, Neue Folge, Bd. l, p. 189. — FORSKAL= Oceania epiicopalis FORBES; BROWNE, 1896, Irish Naturalist, p. 180; 1895, Proc. and Trans. Liverpool Biol. Soc., vol. 9, p. 258. — BEDOT, 1901, Revue Suisse de Zoo]., tome 9, p. 487; Ibid., 1905, tome 13, p. 150 (all literature to 1850). — BROWNE, 1903, Bergens Museums Aarbog, No. 4, p. 11. MAAS, 1904, Result. Camp Sci. Prince de Monaco, fasc. 28, p. 15, plate l, fig. 9. — BROWNE, 1905, Proc. Royal Soc. Edinburgh] vol. 25, p. 760. (?) Tiara intermedia, BROWNE, 1902, Annals and Mag. Nat. Hist., ser. 7, vol. 9, p. 277 (Falkland Islands, South Atlantic). Gervonia octona, FLEMINC, 1823, Edinburgh Philosoph. Journ., vol. 8, p. 299. Oceania octona, FORBES, 1848, British Naked-eved Medusa-, p. 27, plate 2, figs. 3^-3^. The plate is wronglv laln-lt-d *'O. epis- copal is ." Oceania turrita (young medusa), FORBES, 1848, British Naked-eyed Medus.e, p. 28, plate 2, figs, la-zc. Tiara octona, A<;ASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 347. Oceania coronala, ALLMAN, 1871, Monog. Tubularian Hvdroids, p. 33, fig. 8. Tiara octona, H^FCKEI., 1879, Svst. der Medusen, p. 57. Yon Tiara octona, MAAS, 1904, Result. Camp. Sci. Prince de Monaco, fasc. 28, p. 13, plate 2, fig. ll. Bell about 15 to 40 mm. high and 10 to 20 mm. wide. Side walls quite thin, but there is usually a well-developed, solid, apical projection, although this may lie absent. This pro- jection may be conical or cylindrical, with a basal constriction, or pineapple-shaped, etc. There are 12 to 48, usually 24 to 32, tentacles with hollow, laterally compressed, tapering basal bulbs. These tentacles are longer than the bell-height and there is an abaxial ocellus on the outer side of the base of each bulb. The velum is narrow and simple. The 4 radial-canals and ring-canal are wide, flat, and ribbon-like and their edges are often more or less notched and jagged. As they approach the sides of the stomach the radial-canals widen out into funnel-like expansions, so that they embrace the upper halves of the sides of the stomach in the 4 principal radii. The stomach is wide, balloon-shaped, and 4-sided, and fills the upper one-half to two- thirds of the bell-cavity. The 4 lips are at the end of a relatively- narrow, short neck and are complexly folded, crenated and recurved upward. The gonads are 4 horseshoe-shaped regions on the sides of the stomach, the sides of each horseshoe being adradial and the apex aboral and interradial. I he horseshoe consists of an area of more or less transverse folds which, however, anastomose more or less so as to form a network of ridges. In young medusz the ridges of the gonads are more or less parallel and transverse, but in later life they anastomose to form an irregular network. 124 OF THE WORLD. This medusa is very variable in color. The stomach ranges from yellow to red, or from brownish-red to purple. The radial and circular canals may be colorless, to yellow or green. The ocelli are red or dark brownish-purple. The tentacles range from colorless to light-purple. It is widely distributed over the North Atlantic and in the Mediterranean, but it appears to be much commoner on the European than along the American coast. The development has been studied by Hamann, 1883, and Metschnikoff, 1886. Seg- mentation is total and equal and a single-layered, elongate, ciliated larva is found. The entoderm develops from cells which wander into the central segmentation cavity from the hinder end of the larva, so that finally a two-layered planula is formed. The planula attaches itself and the hinder end develops into a hydrorhiza, while the forward end becomes the polypite. The hydrorhiza becomes invested with a thin pensarc and the polypite develops a mouth and 2 or 3 long thin tentacles, which arise at the base of the conical throat-tube. This stage was reached at the end of 16 days in Metschnikoft's specimens, and apparently the hydroid is one ot the Clavidae. This hydroid may possibly be the very abundant and widely distributed Pengonimits rrpens (fig. 66) found oft the Atlantic coasts of Europe from Russia southward, in the Mediterranean, off the Pacific coast of the United States, and at the Falkland Islands and Terra del Fuego, South o America. The stems of the hydroid branch and are covered with a gelatinous investment to which foreign bodies become attached. The polypites are spindle-shaped, with a single oral circlet of tentacles. The medusa-buds arise singly from the sides of the stems. According- to Hartlaub and Browne the medusa is set P> free with but 2 tentacles and 2 small tentacle-bulbs. Forbes described the 4-tentacle stage as Oceania titrnta. the 8-ten- • o tacle condition as O. octona, and the medusa with 12 tentacles as 0. episcopalu. Some of the recent literature relating to the hydroid P. repens is here presented, though it must be borne in mind that this has not been proven to be the hydroid of the medusa in question. Pengonimits re pens + P. minutus, ALLMAN, 1872, Monog. Tubul. Hydroids, p. 521, plate II. Perigommus repens, GRAEFFE, 1884, Arbeit. Zool. Inst. Wien., Bd. 5, p. 350. (At Trieste, Adri- atic. Rare. Medusae produced in May). — DU PLESSIS, 1888, Recueil Zool. Suisse, tome 4, p. 539. — BROWNE, 1896, Proc. Zool. Soc. London, p. 462 (P. minutus ALLMAN = P. repens). — BONNEVIE, 1899, The Norwegian North Atlantic Expedition, 1876-1878, vol. 26, Hydroids, p. 41 (from Norway). — CALKINS, 1899, Proc. Boston Soc. Nat. Hist., vol. 28, p. 539, plate I, figs. 3-3 D (from Puget Sound). — TORREY, 1902, California Univ. Pub. Zool., vol. I, p. 29 (Pacific coast, California to Washington). — HARTLAUB, 1905, Zoolog. Jahrbiichern, Suppl. 6, p. 530, fign. K, L, M (from the Falkland Islands and Terra del Fuego). Turris rotunda. l>i,in,ra rotunda, QUOY ct GAIMARD, 1827, Annal. des Sci. Nat., tome 10, p. 181, plate 6 A, figs, i, z. Tiara rotunda, HAECKEL, 1879, Syst. der Medusen, p. 57, taf. 3, fign. 9, lo. — BEDOT, 1905, Revue Suisse de Zool., tome I}, p. 151 (all literature to 1850). Bell cubical without a pointed apex; 20 mm. high, 20 mm. wide. Bell-cavity only two- thirds as deep as the bell-height. 8 tentacles much longer than the bell-height, with conical basal bulbs. A large, dark-red ocellus on the outer side of each tentacle-bulb. Stomach small, swollen, globular, and confined to the upper third of the bell-cavity. The lips are short, much folded, and with a row of nettling warts around their edges. The gonads consist of 4 pairs ot longitudinal, swollen areas, each thrown into 8 to 10 cross-foldings, on the adradial sides ot the stomach. The stomach, gonads, and tentacle-bulbs are carmine, lips rose-red. 1 i'.. i<>>. — Perigonimus repent, after Him k in British Hydroid Zoophytes. .\\TIHtMKIirs.K TI'KlilS. I!'.". Canals yellow. Found by Ouoy and Gaimard, and later by Haeckel, in the Straits of Gib- raltar. Development unknown. Turris papua Lesson. Tuna papua, LFSSON, 1843, Hist. Zooph. Acalephes, p. 283; Prodromus, 1837, No. 36. — EYDOI x I:T SOILEVKT, 1X41. Voyage de la Bonne, tome 2, p. (t\q, plate i, figs. 1-3. — HAECKKL, 1879, Sysl. der Meduscn, p. 58. — MAAS, 1905, ( i doten M.-dusen der Xibaga Expedition, Monog. 10, p. 14, taf. l, fig. 13; 1906, Kevue Smsse ilr Zool., tome 14, p. 8X. BF-UOT, 1905, Revue Suisse de Zool., tome 13, p. 150 (all literature to 1850). .fyuorea tniiTti, LESSON, 1829, Voyage de la Coqiiille, Zool., p. 127, plate 14, fig. 4. (?) Tiara ocranica, AGASSIZ, A., and MAYER, 1902, Mem. Mus. Comp. Zool. at Harvard College, vol. 16, p. 141, plate I, fig. I. (?)Tf dark brownish-yellow. Widely distributed over the Indian Ocean and tropical Pacific. It is probable that this form displays considerable variability in the number of its tentacles and in the color of its gonads. It is closely allied to 'Turns superb a ot Tortugas, Florida, and mav be identical with T. intermedia Browne, from the Falkland Islands. Turris prismatica. Tiara pTiimalifa, MAAS, 1893, Ergeh. der Plankton Exped., Bd. 2, K. c.. p. f»8, taf. 6, fign. 10, 1 1. Bell about 20 mm. in height, 12 mm. in diameter; 4-sided and prismatic in shape. There is no apical projection and the bell-walls are remarkably thick. In the single specimen described by Maas there are 12 tentacles, one at the foot of each of the 4 radial-canals. 3 others in one quadrant, 3 in another, and one in each of the other quadrants. It seems probable that the specimen is abnormal and that there are normally in tentacles. The tentacles arise at a slight distance above the bell-margin. Ocelli ( ?) The gonads are similar to those ot Tuna pilnitii. In the preserved specimen the bell has a 4-sided prismatic shape. Color ( ?) A single individual of this species was found by the Plankton Expedition on August 4, 1 880., in the Gulf Stream. May it not be an abnormal specimen of Turris pileata ( ?) Turris reticulata Haeckel. Tiara retifitlala, HATI-WEI., 1879, Syst. der Medusen, p. 60, taf. 3, fig. 1 1 . Medusa bell-shaped, 12 mm. high and 10 mm. broad. There is a small, conical, apical projection, about 1.25 times as high as it is broad. The stomach is 4-sided and pyramidal, widest below, and its radial edges are bound throughout their length by the 4 radial-canals. The 4 lips are large and much folded. There are 16 tentacles which are longer than the width of the bell, and have large, laterally compressed bases, with ocelli on their outer sides. Their are 8 separate, triangular gonads in the outer wall of the stomach. The surfaces ot the gonads display complex anastomosing folds and swellings. This species was described by Haeckel from preserved specimens obtained in the South Atlantic near the Island ot Tristan d'Acunha. 12f) MEDUSA OF THE WOULD. Turris vesicaria A. Agassiz. Plate ll, figs. 2 and 3; plate 13, fig. 7. Turris vesicaria, AC.ASSIZ, A., 1862, Proc. Boston Soc. Nat. Hist., vol. 9, p. 97; 1865, North Amer. Acal., p. 164, figs. 261-268.— NUTTING, 1901, Bull. U. S. Fish Commission for 1899, vol. 19, p. 375, fig. 86 (abnormal medusa). C.nlablema vesicarium, HAECKF.L, 1879, Syst.der Medusen, p. 64. — GRONBERG, 1898,200!. Jahrb., Abth. Syst., Bd. n, p. 461. Turris efitcopalit, FEWKES, 1881, Bull. Mus. Comp. Zool. at Harvard College, vol. 8, p. 147, plate 3, figs. 1-6. Turris vesicaria, and T. efiscofalis, HARC.ITT, 1904, Bull. U. S. Bureau of Fisheries, vol. 24, p. 36, 2 figs. Catahlema I'tsicarium (young medusa), MAAS, 1904, Result. Camp. Sci. Prince de Monaco, fasc. 28, p. 12, planches I, 2. Adult medusa (plate 13, fig. 7). — Bell about 25 mm. in height and 12 mm. in diameter. There is a large, solid, apical projection which varies greatly in shape, being globular in some individuals, while in others it is cylindrical or conical. Its upper end is often seen to terminate in a small button-shaped projection. The side walls of the bell are quite thin and flexible. There are 16 well-developed tentacles, the basal bulbs of which are quite large and are flattened in a radial direction, so that the tentacle appears to arise from the side of the bell slightly above the bell-margin. These well-developed tentacles are very flexible, and when ejctended are about 2 to 4 times as long as the bell-height. These basal bulbs are hollow and bear each an abaxial ocellus. In addition to these long tentacles there are 48 very short, rudi- mentary tentacles, which arise from the bell-margin at a slightly lower level than the long ten- tacles. There are 3 of these rudimentary tentacles between each successive pair of long tentacles. There is a single dark-red ocellus upon the outer side of each and every tentacle- bulb, 64 in all. The velum is narrow. There are 4 broad, flat radial-tubes and a broad, circular canal, all of which display jagged edges. The 4 radial-canals enter the stomach by 4 wide, funnel-like openings. The manubrium is large and urn-shaped and there is no peduncle. The mouth is surrounded by 4 prominent, crenulated lips. The gonads occupy 4 interradially situated, longitudinal regions upon the walls of the stomach. Each gonad consists ot a pair of swollen, papilliform, adradial, ectodermal ridges, the outer surfaces of which are thrown into complex, but mainly transverse, folds and corrugations. The color of the manubrium and tentacle-bulbs is cinnamon-brown, the gonads being of a somewhat darker shade. The ocelli upon the tentacle-bulbs are dark-red. y otnig medusa (plate 12, fig. 2). — In the youngest medusa observed the bell is about 2 mm. in height. The walls are thin, and there is a short, conical, apical projection. There are only 4 well-developed tentacles, one at the base of each of the radial-canals. These tentacles have large conical basal bulbs which are hollow. The axes of the tentacle-bulbs are at a slight dis- tance above the bell-margin. In addition to the 4 well-developed, radial tentacles, there are 4 intermediate interradial tentacles which arise from the bell-margin at a slightly lower level than the radial tentacles. The 4 radial-canals are broad and their edges are jagged. The manubrium is large and quadratic in cross-section. The lips are simple. In a medusa 3 mm. in height (plate 12, fig. 3), there were 8 well-developed and 8 immature tentacles. The apical projection was large and miter-shaped, and the lips had folded, notched margins. This medusa is probably an Arctic species. It has been found but rarely south of Cape Cod, and then only in May and June. It is abundant, however, in the harbor of Eastport, Maine, in August, and ample opportunities for observing its growth were afforded. The medusa is remarkable for its voracity and will devour Nanomia cara with great avidity. It is a common thing to observe the medusa in the act of devouring one of these large Siphonophores which may be many times its own size. Maas, 1904, records this medusa off" Bear Island, between Norway and Spitzbergen, so that its distribution is probably circum- polar. Grcinberg records it as being rare in August off" the coasts of Greenland and Spitz- bergen. Turris superba (a variety of T. pileata). Plate 27, fig. 8; plate 28, figs. 3 and 4. Tiara superba, MAYER, 1900, Bull. Mus. Comp. Zool. at Harvard College, vol. 37, p. 34, plate 16, fig. 39; Memoirs Nat. Sci. Museum Brooklyn Inst. Arts and Sci., vol. I, No. I, p. 8, plate 2, fig. 1 1. Bell 5 to 7 mm. high and with a well-developed apical projection. There are 4 long, hollow and 12 small, solid, rudimentary tentacles. The long tentacles are slender, with taper- ing basal bulbs. There is an ectodermal ocellus upon the outer side of the tentacle-bulb of ANTHOMEDU8.*— TURRI8. 127 each of the 1 6 tentacles. The velum is well developed. There are 4 broad, flat, smooth-edged radial-canals and a broad, simple, circular vessel. The 4 radial-canals enter the stomach by 4 wide tunnel-like openings. The manubrium is wide and tills the greater part of the bell- cavity. The 4 lips are recurved and their edges much tolded. The 4 gonads are developed on the interradial sides of the stomach. Each gonad is horseshoe-shaped, the apex of the horseshoe being uppermost, and the sides composed of partially fused, transverse ridges upon the ectoderm of the stomach-wall. The entire gelatinous substance of the medusa is of a delicate rose-pink. The entoderm of the manubrium and tentacles is of a rich rose-color and the entodermal nut' of the stomach is emerald-green. This medusa is quite common at Tortugas, Honda, and among the Bahamas in the summer months. It is one of the most beautiful of American medusae. Turris breviconis Murbach and Shearer. Turrit hrei-iconis, Mi'RBAfl! AND SHKAKKK, 1902, Annals ami Mag. Nat. Hist., ser. 7, vol. 9, p. 73; 1903, Proc. /..nl. s.u . London, vol. 2, p. 170, plate 18, figs. I, 2. Bell cubical, 45 mm. high, 35 mm. wide. More than 140 tentacles in double rows, with contractile muscles on their inner sides and enlarged ectoderm on their outer sides. No ocelli in preserved specimens. Gonads and stomach occupy less than halt of the upper part of the hell-cavity. 4 broad radial-canals with unbranched lateral diverticula. Bell bluish, tentacles, gonads, and stomach dark-red or purple. St. Paul Island, Piihylott' Islands, North Pacific. Turris coeca Hartlaub. Turns rrecu, HARTIM-R, 1892, Nachrichten kgl. Gesell. Wissen. Gimingen, p. 19, fig. i.— MAAS, 1904, Result. Camp. Sci. Prince de Monaco, fasc. 28, p. 17, planchr I, fig. 5. Tinrclhi fHirlhfrifjf'tifti, TRINCJ, 1907, Archiv. Ital. Anat. Embr. Firenze, vol. 5, p. 533 (development and structure of ooevtes). Bell about 30 mm. high and with 24 to 30 tentacles of various lengths. The tentacle- bulbs lilf. H\KI k M , 1*74, Sv\t . .Icr Mr ilusen, p. f»l , taf. 4, figs. 2, 3. — \>* VINSI N, lS»n, Vui . Mrddrl . N .M For. Kjdhenh.ivn (5), Bd. 4, p. 144. -Km KIMUKC., iSSo, Vergleu hen, I phvsiolog. Suidien /u Turnv, etc., Aht. 5, p. 124 (reactions to curare and strychnine). Bell cylindrical, with a well-developed, conical, apical projection. It is 30 to 40 mm. in height and 15 to 20 mm. in diameter. There are 50 to 100 short tentacles, which appear as if arranged in two rows owing to the tact that the bases ot the larger ones extend a slight dis- tance up the sides ot the bell above the margin. KM.. 68. — Turrii digitalis, after Haeckel, 1879. Fn;. 6<). — Corri* i\ilf,/>liilnilr>iat after Haeckel, in S\st. »lrr MeJuseti. There are 8 strands ot longitudinal muscle fibers within the wall of the subumbrella. These strands lie close to, and upon both sides ot, the 4 radial-canals. The radial-canals are broad and flat. In its upper halt each radial-canal is a simple, flat tube with a straight edge. In their lower halves, however, the canals become broader and give rise to many small side branches which end blindly. The manubnum is very large and fills the greater part ot the hell-cavity. The mouth extends to the level of" the velar opening. There are 4 prominent crenulated lips. The gonads occupy 4 interradially situated, longitudinal regions upon the wall of" the stomach. Each gonad consists ot" a double row of papilliform ridges, the outer surfaces of which are thrown into complex folds and corrugations. The stomach is purple or reddish-brown and the lips are rose-colored. The gonads are darker in hue than the stomach. The tentacle-bulbs are orange or yellow and their outer ends are white. The bell is transparent. The 8 muscle-strands in the subumbrella are yellow. 130 MEDUS.TC OF THE WORLD. The species is found in the North Atlantic. It has been taken off the Shetland Islands, between Greenland and Iceland, between Iceland and the Hebrides, in the North Sea, and off the west coast of Greenland. It is probably an Arctic form, of circumpolar distribution. Genus CONIS Brandt, 1834. (.'own, BRANDT, 1834, Recueil des Actes-seances publ., Acad. Imp. Sci. St. Petersbourg, p. 19 (of the "separate"); 1838, Mem. Acad. Imp. Sci. St. Petershourg, ser. 6, vul. 4, par. 2, p. 355. — HAF.CKKL, 1879, Syst. der Medusen, p. 55. The type species is Conis niitrnta Brandt of the Bonin Islands, North Pacific. GENERIC CHARACTERS. Similar to Pandea, but the tentacle-bulbs give rise to special ocellar clubs, which project outward around the margin. The gonads consist of simple, longitudinal swellings on the sides of the stomach and have smooth outer surfaces. The hydroid is unknown. Conis mitrata Brandt. Conit mitrata, BRANDT, 1834, Recueil Actes publique, Acad. Sci. St. Petersbourg, p. 19 (separate); 1838, Mem. Acad. Imp. Sci. St. Petersbourg, ser. 6, vol. 4, par. 2, p. 355, pi. 2. — HAECKEL, 1879, Syst. der Meduseo, p. 55. — BEDOT, 1905, Revue Suisse de Zool., tome 13, p. 133 (literature 1834-50). Bell 50 mm. high, 35 mm. wide, with a short, conical apex. 64 short tentacles, each with a club-like ocellar bulb projecting from the outer side of the basal bulb at the margin. The tentacles are shorter than the bell-height. The stomach is barrel-shaped, with 4 not very complexly folded lips, having their margins studded with nematocyst-warts. Lips are at a level about half-way between the velar opening, and the inner apex of the bell-cavity. Stomach light-red. Tentacle-bulbs blue. Ocelli black. Bonin Islands, North Pacific. Conis cyclophthalma Haeckel. Cmit r\rlo[>hihalma, HAECKEL, 1879, Syst. der Medusen, p. 55, taf. 4, fig. i. Bell pyriform, with thin sides and without an apical projection; 15 mm. high, 12 mm. wide. There are 52 tentacles with very elongate, conical basal bulbs, one-third as long as the tentacles themselves. The outer ends of the tentacles are thin and flexible while the basal bulbs are stiff. The tentacles are longer than the bell-height. At the base of each tentacle on the abaxial side of the margin there is a short club-like projection which contains a black, ectodermal ocellus. There are 4 straight-edged radial-canals and a simple ring-canal. The stomach is very large and almost fills the bell-cavity. There are 4 very large, complexly folded lips with their margins studded with nematocyst-warts. The lips are at about the level of the velar opening. (See fig. 69.) Haeckel figures and describes 4 longitudinal, swollen gonads on the "perradial" sides of the stomach. Their outer surfaces are smooth and they are filled with ova. He represents them as being completely separated in the interradii. The gonads are probably adradial or interradial ( ?). Color ( ?) Haeckel studied a preserved specimen in the Museum of Copenhagen. It was obtained near Gibraltar in lat. 30° iff N., long. 2° 23' W. Genus CALYCOPSIS Fewkes, 1882. Calycopsis, FEvvk'ts, 1882, Bull. Mus. Comp. Zoo], at Harvard College, vol. 9, p. 304. The type species is Calycopsis typti Fewkes, from the Gulf Stream off the coast of the United States. GENERIC CHARACTERS. Tiarinae with 16 separate, simple, unbranched radial-canals; 4 radial, 4 interradial, and 8 adradial. Gonads are composed of a row of leaf-like, transverse foldings along each of the 8 adradial sides of the stomach. Lips ( ?) Tentacles simple. Ring-canal simple, without blindly-ending diverticula. Development unknown. ANTHOMEDUSjE— CALYCOP818. 131 Calycopsis typa Fewkes. (,Wv<'//m< t\f>.wKts, lSS2, Bull. Mus. Comp. Zool. at Harvard College, vol. 9, p. 304, platr i, fig. 54. Bell higher than a hemisphere, with evenly rounded top and vertical sides. External surface smooth, bell-walls thin, thicker above than near the margin. Size ( ?) There are 16 radial-canals and 16 marginal tentacles, one at the base of each canal. These tentacles are about as long as the bell-height and are flexible with some- what club-shaped outer ends and very small basal bulbs. No lithocysts or marginal bodies other than the id ten- tacles. The stomach is very wide and fills almost the whole ot the inner half of the bell-cavity. The gonads are devel- oped upon the sides of the stomach and appear as a series of transverse, leaf-like ndges on both sides of each of the 4 principal radial lines of the stomach. They are thus adradial in position and their manner of folding resembles the condition seen in the gonads of Turns. The sides of the stomach are bound to the subumbrella by 4 radially situated partitions. There are 16 straight, narrow radial- canals: 4 of these are perradial, 4 are mterradial, and 8 adradial. In alcoholic specimens the ovaries were dark- brown. Tentacles and bell-walls white with a tinge of bluish color. 4 specimens were found by the Allxitross, in 1880 81, off the Atlantic coast of the United States, in deep water along the Gulf Stream. Form of lips ( ?) Size ( ?) Ocelli ( ?) Fi(i. 70.— Cai\rof>si* t\f>ti, after Fewkes, in Bull. Museum Comp. Zoo), at Harvard College. Subfamily MARGELIN^ Haeckel, 1879. Oceanidx with oral tentacles and with 4 simple, unhranched radial-canals. Gonads on the mterradial, or adradial sides of the manubnum; the mature genital products are tound in the ectoderm. i . Tribe Cvttftdi: Marginal tentacles arise singly from bell-margin and are not grouped into clusters. Oral tentacles are unbranched, simple, or degenerate. They are found in all forms excepting in the degenerate medusa; of Stvlactis. Cyttris, ESCHSCHOLTZ, 1829. Cythosa± Cytcrandra HAECKEL, 1879. 8 or more marginal tentacles. Oral tentacles present. When present the peduncle is solid. Hydroid: Podocorynt. Turritopsis, McCRADY, 1856. 8 or more marginal tentacles. Entodermal walls of the 4 radial-canals, above stomach, are composed of highly vacuolated cells forming a peduncle. Mouth studded with a row of nematocyst-bearing knobs. Hydroid: Dendroclara. Oceania, sens., KOLLIKER, 1853; GECJENBAUR, 1856. Medusa similar to Turritopsh, but with a simple, solid, gelatinous (not vacuolated) peduncle. Hydroid: Clava-like. Stvlactis, ALLMAN, 1864, degenerate medusae with 4 to 8 rudimentary marginal tentacles and no oral tentacles. Medusa: mature upon liberation from hydroid. Hydroid: Stylactts; closely related to Podocoryne. 2. Tribe Thamnostomeidi: With branching oral tentacles. With simple marginal tentacles, not grouped in clusters. Thamnost\ltis, HAECKEL, 1879. 2 diametrically opposed, marginal tentacles. Development unknown. Thamnitis, HAECKEL, 1879. 4 radially situated, marginal tentacles. Development unknown. L\mnorea, PERON and LESUEUR, i8og= Ltmnorea+ Thamnostoma, HAECKEL, 1879. 8 or more marginal tentacles. Development unknown. 3. Tribe BougatnviUidi: Marginal tentacles grouped into clusters. Each cluster consisting of 2 or more tentacles. The 4 oral tentacles may be simple or branched. Bougainvillia, LESSON, 1836= Margflis + Lizusa± Hippocrene, HAECKKL, 1879. With branching, oral tentacles. With 4 radially situated clusters of marginal tentacles, all of one sort. Hydroid: Bougainvillia. Ntniopsis, L. AGASSIZ, 1849. With branched oral tentacles. With 4 radially placed clusters of marginal tentacles, consisting of a median pair of club-shaped tentacles and a number of lateral filiform tentacles in each cluster. Hydroid: Bougainvillia, Ratfikfti, BRANDT, 1857 = Mnr^fll turner Lizzia+ Lizztlla+ Rathkeu, HAM-KM., 1^79- With X dusters of marginal ten- tacles. Mature hydroid unknown. Cfiiarellat MAAS, 1X97. With 16 (8 double) clusters of marginal tentacles. Circular can.il gi\rs off 4 intrrradi.il, blindly ending, centripetal branches. 132 MKDUS.E OF THE WUHLI). Genus CYTjEIS Eschscholtz, 1829. \_uiiiu. /juui . tii iidi v di u \^<_mcgc, vui. ji, u< iwi . uttuvv i> t, i ywjj ixcfi . i \_c^iun i cd London, Supplementary Report 27, p. 135. — CHUN, 1895, Bibliotheca Zoologica, Heft 19, p. 11 (law of budding). (1 \tiris. + Cubogasterf HAECKEL, 1879, Syst. der Meduscn, pp. 73, 75. Aron Cytais, MAVER, 1900, Bull. Mus. Comp. Zool. at Harvard College, vol. 37, p. 39. C.\t,ris, VANHOFKEN, 1891, Zool. Anzeiger, Bd. 14, p. 444. \on C \tj-is, SARS, 183^, Beskriv og Jagttag., p. 28. Ctibogasttr, HAECKEL, 1864, Jena. Zeit. fur Naturw., Bd. i, p. 341 (vuung of Cy/.r;.0- \igritina, STEENSTRUF, 1837, Acta et Catal. Musei Hafmensis, Hauniic. GENERIC CHARACTERS. MargeliiiEE with 4 simple, radially situated, marginal tentacles and with 4 or more simple, unbranched oral tentacles. The hydroid is unknown. The type species is Cyta-is tetrastyla Eschscholtz, 1829, of the Mediterranean and eastern parts of the tropical Atlantic. Eschscholtz states that it has 8 simple oral tentacles and 4 marginal tentacles, but he figures at least 10 oral tentacles. More recently species of Cyttcis have been found with 8, 16, or even 32 oral tentacles. Tubular Synopsis of the Medusae of Cytirts. C. tetrastyla C.atlantica = C. pusilla C. vulgaris C. herdmani Eschscholtz, C. macrogaster Gegenbaur, 1856. Agassiz and May- Browne, 1905. 1819.* Haeckel, 1879 er, iSgg.-f- = C. tetrastyla Eydoux ct Soule- yet, 1841 = C. nigritina Haeckel, 1879^ Shape and size of Cubical to domelike Pyrtform. 5 high, Oval. 4 high, 3 Prismatic, flat above Oval. 3.5 high, 3.5 bell in mm. 2 to 3 high, 2 to 3 6 wi e. wide. 5 high, 3.5 wide. wide. wide. Character of the 4 Similar each to each. As in C. tetrastyla, 2M- long. With IT long, with large As in C. atlantica. marginal tenta- 2r+ long. Basal but with large small basal bulbs. basal bulbs. cles. Length in bulbs small. pynform basal terms of bell- swellings on ex- raJius (r). umbrella above each tentacle. Shape and size of Flask-shaped, Very large, flask- Stomach oval. Stomach oval to Wide flask-shaped, manubrium. mounted on shaped. Two- Mounted upon spindle-shape ', on short peduncle peduncle. Mouth thirdsto i .5 times conical peduncle half to two-thirds Two-thirds as at level of velar as long asdeptli of not quite as long aslong asdepth of long as depth of opening. bcll-cavitv. No as stomach. bell-cavity. bell-cavity. peduncle in Mouth at middle Young medusa has mature medusa. of bell-cavity. short peduncle, but this is not seen m mature animal. Number of oral 4 to 6 8 to 32 12 to 24 32 50 to 60 tentacles. Character of 4 interradial swell- Numerous medusa- 4 interradial swell- 8 adradial gonads 4 perradial? or 8 gonads and ings. buds on upper ings. near base, on sides adradial ? g<>n.i;K medusa-buds. half of manubrium. of stomach. No medusa-buds. Color. Stomach and tenta- Stomach yellowish. Stomach and gonads Stomach and tenta- ? cle-bulbs brown. Gonads and tenta- vellowish-brown. cle-bulbs red and cle-bulbs violet- Tentacle-bulbs green. Abaxial brown, red, or black. entoderm red, nearly black. superficial green. Where found. Mediterranean, and Mediterranean to Mediterranean. Fiji Islands to Malav Coast of Ceylon. tropical Atlantic. Atlantic to Archipelago, trop- Canary Islands. Brazilian coast. ical Pacific. *Probably young and immature. Possibly young of C. atlantica? •f For details see text. AXTHO.MKDI-S.K — cvr.Kis. i:j;; The gonads ot C\t, excepting " (*.ul»n\:i>t, i gemmascens" which I take to be an abnormal young Rathkc/i octoputittntu with only 2 well- developed and 6 retarded marginal tentacles. Broch, 1905 (Bergens Museums Aarbog. No. 11, p. 4), states that the marginal tentacle-bulbs may range from 4 to 8, and that well- developed tentacles may be absent. Cytaeis tetrastyla Eschscholtz. ( 'v/,M \ trrr STKKNSTRUP, 1837, Catal. Musei Hafniensis. C\(.rn ici',i^\l,i, KVDOUX et SOULEYET, 1841, Voyage de la Botnir, tonic 2, p. ^41, pl.ite 2, figs. 4 to i^. C.M.ris marrogauer, HAKCKEL, 1879, Syst. der Medusen, p. 74, taf. 6, fig. I.— CHIN, 1X1)5, Bihliotheca Zo-ilogna, Mi-ft iij, p. 4^ (budding of medusa from the manubrium). (;\[,ris nigritina, HAECKEL, 1879, Syst. der Medusen, p. 74, taf. 6, fign. 2-5. — MAAS, 1904, Result. Cam p. Sa. Pririo- il<- Mi'iiani, l.i i . 28, p. 8, plate I, figs. 3, 4. Bell bluntly conical or pear-shaped, about 6 mm. high and 5 mm. wide. There are 4 stout radially placed marginal tentacles longer than the bell-diameter. The bases ot these tentacles are very thick and extend up the sides ot the bell as large, bulbous, pear-shaped swellings. These swellings bear a large crescent-shaped mass of entodermal pigment on their lower, outer sides. These bulbous swellings are each about one-eighth to one-fourth as high as the bell. The velum is well developed. There are 4 simple, straight radial-canals and a simple ring-canal. The manubrium is large and lacks a peduncle. It is 0.5 to i.^ times as long as the depth of the bell-cavity. Normally it is probably about as long as the depth of the bell-cavity. There are numerous medusa-buds upon the upper halt ot the stomach- wall and these are seen in various stages ot development. 1 he mouth is surrounded In .1 circlet of 8 to 32 short, slender, oral tentacles, each of which terminates in a nematocyst-knob. The stomach is reddish-brown and the tentacles brown, with tentacle-bulbs nearly black. This medusa is found in the Mediterranean and Atlantic trom the shores ot Africa to flu- Brazilian coast. Haeckel describes 4 gonads at the points ot |uncture ot the 4 radial-canals with the stomach, but this is probably erroneous, tor it is improbable that the gonads are m the principal radii. Haeckel distinguishes C. nigritimi with manubrium half as long as the depth ot the bell-cavity, and with 16 to }2 oral tentacles; and ('.. niiu-rngantfr with manubrium 1.5 tinns as long as the depth of the bell-cavity and with 8 to 16 oral tentacles. _ In 1904, Maas dcsciilu s a very similar medusa, under the name ot (',. nigi'itnm, in which the manubrium is about two-thirds as long as the depth of the bell-cavity and has i i oral tentacles. These medusa- are so closely similar in all other respects that I am of the opinion that they are men-l\ growth and contraction phases of one and the same species. Following the usual rule of pre- cedence, it appears that the specific name should be "atlantica," this being the designation proposed by Steenstrup, 1837. 134 MEDUS.E OF THE WOULD. Cytaeis pusilla Gegenbaur. (.'v/.n'j fuiilla, Gr.iiiNBAi-R, 1856, Zeit. fur wissen. Zool., Bd. 8, p. 228, taf. 8, fig. 8. — KEKERSTEIN UNO EIILERS, 1861, Zoolug. Beitrag., p. 84, taf. 13, fign. 8, 9. — HAECKEL, 1879, Syst. der Medusen, p. 75. (?) Cubogasler diuonema (young medusa), HAECKEL, Ibid., p. 76. This medusa is recorded from the Mediterranean. For details see tabular synopsis of the medusae of Cyttcis. Haeckel describes "Cubogaster dissonema" a small medusa 2 mm. high, with 2 well- developed and 2 immature or rudimentary marginal tentacles, and 8 oral tentacles. This he found at Croisic, Bretagne, Atlantic coast of France. It may be the young of C. pusilla ( ?) 7'- Flc. 71. — Cvttfis atlantica, after Maas, in Result. Camp. Sci. Prince de Monaco. FIG. 72. — Cytefis " macrogaster" ((7. atlantica), after Haeckel, 1879. FIG. 73. — C.ytas'n pusilla, after Gegenbaur, in Zeit. fur wissen. Zool., Bd. 8. Cytseis vulgaris Agassiz and Mayer. Cyttsis vulgaris, AGASSIZ and MAYER, 1899, Bull. Mus. Comp. Zool. at Harvard Coll., vol. 32, p. 161, plate 2, figs. 3-5. — MAAS, 1905, Craspedoten Medusen der Siboga Exped., Monog. 10, p. 8, taf. i, fign. 4-7; 1906, Revue Suisse de Zool., tome 4, p. 85, fig. 3, plate 2. Mature specimens of this medusa are described by Maas from the Malay Archipelago. Agassiz and Mayer described only half-grown medusae from the Fiji Islands. Mature medusa. — Bell 5 mm. high, prismatic, 4-sided, and with a flat top. There are 4 thick, radially placed, marginal tentacles, each somewhat shorter than the bell-height. These tentacles end in blunt tips and have large hollow basal bulbs. Maas describes a thick lens- shaped swelling on the abaxial side of each tentacle-bulb, but his specimens are somewhat contracted through preservation in formalin. The basal bulbs of the living medusas studied by Agassiz and Mayer were large and swollen, but lacked the lenticular, ectodermal swellings. On the other hand Agassiz and Mayer found only half-grown medusae, and it is possible that the peculiar form of the basal bulbs described by Maas may be characteristic of the full-grown, ANTHOMKDI s.K (VI.KIS, I'l i|« M •( >IM NK. 135 but not of the half-grown, medusa. The velum is well developed. The 4 radial-canals and ring-canal are slender and simple. The manubrium is spindle-shaped and shorter than the depth of the bell-cavity. In the halt-grown medusa there is a short conical peduncle, but this was not seen by Maas in his large specimens. The mouth is at the extremity of a bluntly pointed, conical neck, and is a simple round opening. 32 or more short, slender, filiform, unbranched oral tentacles arise from a zone above the mouth. Each oral tentacle is solid and ends in a knob-like cluster of ncmatocysts. 1 he gonads are found on the upper interradial sides of the stomach and appear as a pair of longitudinal swellings in each of the 4 interradii. They are not developed on the 4 radial lines of the stomach. The eggs protrude over the surfaces. In the formalin specimens studied by Maas, the gonads were yellow, the axial entoderm of the stomach dark-red, as were also the entodermal parts of the tentacle-bulbs. There is some green pigment in the ectoderm of the tentacle-bulbs. In the immature specimens from Fiji, studied from life by Dr. Agassiz and his assistant, the entoderm of the outer part of the manubrium and of the tentacle-tips was green, while there was red pigment in the axial part of the stomach and in the tentacle-bulbs and adjacent parts of the 4 radial-canals. In the young specimens from Fiji the oral tentacles ranged from 4 to id, while in those found by Maas in the Malay Archipelago, they ranged from 8 to 32. Found in abundance on the surface among the Fiji Islands in November to January. Maas found numerous specimens in the Siboga collection from the Malay Archipelago, Sulu, Damar, Daiam. Sabuida, Gisser, Mampa Straits, and Saleyer; and from Amboma, 1906. Cytaeis herdmani Browne. (.'w//\ ftciil'tifini, BKDWNK, 1905, IV.ul OvMer I'ishenes, GuH nf Mjnaar, Km . Soi . LMIU|IUI, Suppl. Report 2^, p. i;^, pl.itr I. fig. i ; plate 4, fig. 12. Umbrella about 3.5 mm. in width and height. Somewhat bell-shaped with fairly thick walls. 4 marginal, long tentacles with very large, spear-head-shaped, basal bulbs one-third as lung as the bell-height. The ectoderm of the tentacles is thickly crowded with nematocysts. The entoderm of the tentacles and basal bulbs is pigmented. Velum narrow. 4 wide, straight radial-canals. Stomach about as wide as long placed upon a short peduncle and extending a little more than half-way down the cavity of the bell. A row of 50 to fto short, equalh spaced oral tentacles, each ending in a knob of nematocysts. Gonads form 4 (perradial ?) swellings extending the entire length of the stomach. Color ( ?) Coast of Ceylon; Chilaw Paar, and Cheval Paar; March to November. Genus PODOCORYNE Sars, 1846. ( >)l)\smtirfho;a, PIIILIPPI, 1842, Archiv. fiir Naturgesch., Jalirg. 8, Bd. i. p. ',7, t.if. i, tic,. 3. I'aitarortnr, SARS, 1846, Fauna littor. Nurveg., tome I, p. 4, t.if. I, figs. 7-18. Hl\< ks, iXdS, British Hvilroul /.,„, phvtes, p. 29.— ALLMAN, 1871, Monograph Tubul. Hydroids, p. 348. Hi MIM., iK'jj. |<>nm. M.nplml., vol. 9, p. 20^. HMtiixir., 1905, Znolog. Jahrbuchern, Supplement 6, p. 523. l'u,lm-or\na, KROHN, 1851, Arch, fiir Naturges., Jahrg. 17, Bil. I, p. 263. Dvimorpliosa, Ai.^si/, A., 1865, North Amrr. A. ,il., p. id}. I'm N. 1X9^, Bihli.itlu-ta X.n.il., Hi-ft n), I.fi;. I, pp. 12, ;;. MAAS, 1905, Craspcdotcn M.'iluscn ilor fiibo^a KxpcJitmn, Mnnni;. 10, p. 8. V«MIM> » > N, |S.||. /...ol. An/i-ri;iT, Bil. 14, p. 444. — BEUOT, 1905, Rcvur Suisse dc Zo..]., tmn<- i ;, p. 7-, ; I'-niotorynt, Ibid., p. 102 (literature to 1850). — MAAS, 1906, Revue Smssr .It- /.mil., form- 14, p. 86, plate }, fit^. 8. Dysmorphoso+ Cyteeandra, HAKCKKI-, 1879, Syst. iler Medusen, p[i. 76, 79. Tuiritopsis, AI^ASSIZ, A., 1865, Nnrth Amer. Acal., p. 167. The name l)\litisi \n< . In the absence of proof as to whether Philippi's hydroid develops medusae or not, we are unable to decide with certainty which name should stand, but there is no probability that Philippi's hydroid will ever be determined and we niav avoid confusion by considering it obsolete. l.'JG MIClirS.K I IF THK WORLD. GENERIC CHARACTERS. Margelinae with 4 or more simple, unbranched oral tentacles and with 8 or more simple marginal tentacles. When present the peduncle of the manubrium is simple, solid, and gelat- inous. The hydroid stock is Podocoryne. Haeckel, 1879, restricts the genus "Dysmorphosa" to include only those medusae which have 8 marginal tentacles. Medusze bearing more than 8 tentacles he places in a new genus "(1 \iirunJi n." Inasmuch as specimens of Podocoryne fulgurans and P. cnrnea are often found which have more than 8 tentacles, we consider Haeckel's definitions to be too restrictive. Van- hoffen, 1891, defines Dysmorphosa, as we do Podocoryne, to include medusa, with 8 or more marginal tentacles. PoJ'jiftr \iii- may be distinguished from Lymtiorca by its simple unbranched oral tentacles. In Turritopsis there are no oral tentacles, but only 4 simple lips studded with nematocyst- knobs, and the presence of simple oral tentacles in Podocoryne at once distinguishes it from Turritopsis. It is distinguished from Cyta-is by its having eight or more marginal tentacles, whereas C ytieis is restricted to medusae bearing 4 marginal tentacles. In Cvtccis the oral ten- tacles are commonly more than 4, whereas there are only 3 known species of Dysniorp/ios/i bearing more than 4 oral tentacles. Podocoryne is possibly derived from the more simply organized C \ta-is. Podocoryne carnea Sars. Plate 14, figs. 2 to 6; plate 15, fig. 14. SYNONYMS OK THK EUROPEAN FORM. ( •) Dysmorphosa conchicola, PHILIPPI, 1X42, Archiv. fiir Naturgesch., Jahrg. 8, Bd. i, p. 37, taf. i, fig. 3. Podocoryne carnra, SAKS, 1846, Fauna Littor. Norveg., p. 4, taf. i, figs. 7-18.— KROHN, 1851, Archiv. fiir Naturgesch., Jahrg. 17, Bd. I, p. 266. — HINCKS, 1868, British Hydroid Zooph., p. 29, plate 5, 6 figs. — ALLMAN, 1871, Monograph Tubul. Hy- droids. p. 349, plate 16, figs. 1-9. — DEVARENNE, 1882, Archiv. de Zool. Ejpcr., tome lo, pp. 645, 674, 683, plate 33, figs. 6-15; plates 34, 36-38; 1882, Compt. rend. Paris, tome 94, p. 892. — WF.ISMANN, 1883, Seiualzellen bei den Hydromedu- sen, pp. 63-72, taf. 19, fign. 1-13. — BROWNK, 1896, Proc. Zool. Soc. London, p. 463. — DEVARENNE, 1881, Annals and Mag. Nat. Hist., ser. 5, vol. 9, p. 134.— HAMANN, 1882, Jena. Zeitschrift fur Naturwissen., Bd. 15, p. 517, taf. 20, fign. I, 3, 4(histology of hydroid). — JICKELI, 1883, Morphol. Jahrb., Bd. 8. p. 621, taf. 27 (histology of the hydroid). — GRAEFFE, 1884, Arbeit. Zool. Inst. Wien, Bd. 5, p. 347. — ISHIKAWA, 1888, Zeit. fiir wissen. Zool., Bd. 47, p. 621, 6 fign. (origin nf egg cells). — BEDOT, 1905, Revue Suisse de Zoo]., tome 13, p. 103 (literature 1842-1850). — RITCHIE, 1907, Trans. Roy. Soc. Edinburgh, vol. 45, p. 1^23 (from Cape Colony, South Africa). Dysmorphosa carnea, HAECKEL, 1879, Syst. der Medusen, p. 77. (:\[,ti! exi^nti, HAECKEL, Ibid., p. 634. Podocoryne h'fckcln, HAMANN, 1882, Jena. Zeit. fur Naturwissen., Bd. 15, p. 519 (young stocks of I', carnea ?). (?) Podocoryne conchicola (Philippi) in part, HARGITT, 1904, Mitth. Zool. Station Neapel, Bd. 16, p. c8l, fig. 26, taf. 22. SYNONYMS OF THE AMFRICAN REPRESENTATIVE. Turritopsis nutricula, AGASSIZ, A., 1862, Proc. Boston Soc. Nat. Hist., vol. 9, p. 97, figs. 22, 23; 1865, North Amer. Acal.,p. 167* figs. 269, 270. — FEWKES, 1881, Bull. Mus. Comp. Zool., vol. 8, p. 153, plate 4, figs. 4, 7-10. t'.nli \. The medusa-buds arise from a zone which is slisrhtlv below D the circlet of oral tentacles. From 4 to 8 of these buds are usually to be seen upon each gonostyle. According to Mar- tha Bunting, 1894, it appears that the medusa-bud arises as an outpushing of both entoderm and ectoderm of the gonostyle. As the bud progresses in its development, we find the ova in the entoderm of the manu- brium. When a later stage has been reached the}' migrate from the entoderm into the ectoderm. The spermatozoa, on the other hand, originate in the ectoderm of the manu- brium, as was shown by Weismann, 1883. When set free the medusa usually has 8 ten- tacles: 4 radial and 4 interradial. The radial tentacles are usually better developed than the interradial and in some individuals there are but 4 tentacles at the time of liberation, the inter- radial ones not yet being developed. It is remarkable that while in some stocks of Podocoryne the medusae are set free in an immature state, in others the medusae are mature when liberated, the manubrium being distended with sperm or ova, which are discharged almost immediately after the medusa is set free. It is possible, as Allman, [871, suggests, that this difference may be due to the influ- ence of local conditions, which may be favorable in the one case and not so in the other to an advanced development of the medusa. Krohn, 1851 , and I. oven, [857, have observed Stocks ol the European form of PvJticnrvni* which were setting ticc mature medus:e. Indeed, we appeal to have a parallel case in Stinm on the Massachusetts coast, where immature medusae are liber- ated during the early spring months, whereas the medusae become ripe, discharge then genital products and wither upon the hydroid stock in May. Good figures of I'lnlmm \n<- stocks which are setting free immature medusae have been given by Sars, 1846; Ilincks. ifsViS; Allman, iX-i; etc. When set free the medusae commonly have 8 tentacles, 4 radial and 4 interradial. The radial tentacles are usually more advanced than the interradial, and in some few individuals Number of tentacles when liberated from hvdroul. Number of tentacles possessed bv mature medusa. Mrilus.i-lnuls on interradi.il suit's i>f stomach of medusa. Usually 4 to 8, rarely ih (Graeffe). Observed by Sars, 1846. 4 in S. Usually 8. 16 to 32. I'su.illv .iln.ut 24. No medusa-buds observed . 138 MF.ni'S.K OF THK WORLD. there is no trace of interradial tentacles at the time when the medusa is liberated. The manu- hrium is short and fusiform and the mouth is surrounded by 4 radially situated, oral tentacles, each of which terminates in a knob-shaped cluster of nematocysts. When set free the medusa is about 0.5 to 0.6 mm. in height. In those medusae which are set free in an immature condition there are at first 8 tentacles, but these increase in number as growth proceeds and finally, when the medusa is about 3.5 mm. in height, there are usually about 32 tentacles, 8 in each quadrant. The manubrium of the young," immature medusa is slender and fusiform, while in those medusae which are set free in a I'u.. 74.— / c - tii'iii-ii, livdroid ami young medusa. Drawn from lift" by Professor William K. Brooks and kindly presented to the author for publication in this work. mature state it is globular and greatly distended with the genital products. The ectoderm of the hydroid is slightly bluish and translucent, while the entoderm is creamy-pink, or silvery- white in color. This species has been found upon the Atlantic coasts ot Europe, in the Mediterranean Sea, and trom Saldanha Bay, Cape Colony, South Africa. Levinsen, 1893, records it from the west coast of Greenland, and we have found it in great abundance in Narraganseit and Buzzard's Bays, on the southern coast of New England. It has not been taken at Beaufort, North Carolina, nor at any station farther south. The medusae are very common in Narra- gansett Bay from the middle of June until October, and I enjoyed exceptional opportunities PLATE 15. Fig. i. Lvmnorfa borealis. Eastport, Maine, September 19, 1898. Fig. 2. Lymnorea borealis. Side view ot the oral tentacles. Fig. }. Lvmnorfa borealis. View ot the nematocyst-capsules upon the oral tentacles. Fig. 4. Lymnorea alexandn, young medusa. Nassau Harbor, Bahamas, June, 1903. Fig. 5. Lymnorea alexandn, mature medusa. Nassau Harbor, Bahamas, July, 1903. Fig. 6. Lvmnorea alexandri. Cross-section showing the gland-cells ot" the mid-region ot a radial-canal of the medusa shown in figure 5. Fig. ". Lvmnorfa alexandrl. Knob-like end ot" one of the oral tentacles showing the nematocysts. Fig. 8. Lvmnorea ale\anJri. Mouth parts ot" the young medusa shown in figure 4. Fig. 9. Lvmnorea ale\andrt. Marginal tentacle. Fig. 10. Turritopsis nutricula, young medusa. Agassiz Laboratory, New- port, Rhode Island, August, 1892. Fig. ii. Turritopsis nutricula, young medusa. Newport, Rhode Island. Fig. 12. Turritopsis nutricula. View ot the lips ot a mature male medusa. Tortugas, Florida, April 6, 1906. Fig. 1 3. Turritopsis nutricula. Aboral view ot manubrium showing the vacuolated entodermal cells surrounding radial-canals. Tortugas, Florida, April n, 1906. Fig. 14. Podocoryne carnea, mature female. Agassiz Laboratory, Newport, Rhode Island, July, 1895. Drawn trom lite, by the author. PLATE 15 10 13 AXTHflMKDrS.F. — PODOrORYXE. 130 for observing their growth and development while studying at Dr. Alexander Agassiz's labor- atory at Newport, in 1892-96. In 188 1-82 de \ arenne concluded that both eggs and sperm-cells originate in the entoderm of the crenosarc of the hydroid and afterwards migrate into the medusa-bud. The more careful researches ot Weismann, 1883, however, refuted this view, showing that the male germ-cells originate in the ectoderm of the budding medusa, but do not wander from their place of origin. On the other hand, the female germ-cells may possibly originate in the ecto- derm; if so they soon wander into the entoderm of the budding gonophore, then into the spadix of the medusa-bud and finally into the ectoderm of the manubrium of the medusa. According tii rlie later studies of Ishikawa and of Bunting, however, the egg-cells t,ri^inntf in the min- der m dl the medusa-bud and afterwards migrate into the ectoderm. Plate 12, figs. 5 to 9; plate 11, figs, i to 5. Adult medusa. — Bell usually somewhat pynform in shape and about I mm. in height. Gelatinous substance very soft and flexible, so much so, indeed, that the medusa is often found to be much distorted and shriveled by the powerful contractions of the circular muscles. Very frequently this contraction causes deep interradial furrows to appear upon the surface of the bell, in the meridian of the radiating muscles of the subumbrella, and I believe that this appearance led Fewkes, 1881, to describe one ot these contracted medusae as a new genus: "Mabella gracilis." There are usually 8, but sometimes 16 (plate 13, fig. 5), long, marginal tentacles with well-developed basal bulbs. These tentacles are quite stift and are carried curled upward. The tentacle-bulbs are large and are filled with entodermal pigment. The velum is wide. There are 4 straight, slender, radial tubes. The manubrium is furnished with a well-developed peduncle (plate 12, figs. 6 to 9), which is quadratic in cross-section. The peduncle has the shape of a frustum of a pyramid, and it extends about one-third the distance from the inner apex of the bell-cavity toward the velar opening. The 4 radial tubes extend down the 4 angles of the pyramid into the gastric part of the manubrium. The gastric- portion of the manuhrium is short and the mouth-opening is situated at the lower extremity of a short tubular neck. There are no prominent lips. 4 radially situated, oral tentacles arise from the sides of the neck. These oral tentacles are quite flexible. They taper gradually and end each in a single, knob-shaped cluster of nematocyst-cells. Medusa-buds are produced upon the sides ot the stomach. These buds arise in the interradn (plate 12, tig. 7), and one usually sees 4 or 5 of them in various stages of development. The place and time of appear- ance of these medusa-buds appear to follow the law demonstrated by Chun, 1895, in Rnthkta ni tripnin'tata. When set free the young medusa has 8 marginal tentacles. It is interesting to observe that while the medusae are still attached to the manubrium of the mother they themselves begin to develop medusa-buds upon the sides of their manubria (plate 12, tig. 7). The entoderm of the tentacle-bulbs is of a delicate salmon-red. The manubrium is some- times colorless and sometimes salmon-red. This medusa is very abundant at Newport, Rhode Island, late in the summer, when it occurs in vast swarms which cause the water, when disturbed at night, to glow with ;i bluish phosphorescence. A large swarm was found in the St. Mary's River, Maryland, near the mouth of the Potomac, in November, 1905; and I have also taken it at Beaufort, North Caro- lina, late in November. It has not been seen at Tortugas, Florida, This species is readily distinguished from Podocoryne rarnea by its much smaller size. Also the manubrium is provided with a well-developed peduncle, while in I1, ctirnnt there is no peduncle. P. fiilgnrntis is very delicate and flexible, while P. faniea is tough and relatively inflexible, A PoJdiat \iii- found at Beaufort, North Carolina, by Professor Brooks, is probably the hydroid of this medusa. The tentacles are usually in whorls of 5. 1 |() MEDUS.E OF THE WORLD. Podocoryne areolata Hincks. Hvilractinia areolata, ALDER, 1861, Trans. TynesiJe Nat. Field Club., vol. 5, p. 225, plate 9, figs. 1-4 (hydroid). Podocorme areolata, HINCKS, 1868, Hist. British Hydroid Zooph., p. 32, plate 6, fig. I. C.\'t.eanilra areolata, HAECKEL, 1879, Syst. der Medusen, p. 79. I I C.\titandra areolata, BROWNE, 1895, Trans. Liverpool Biol. Soc., vol. 9, 'p. 262; 1897, Proc. Zool. Soc. London, p. 817, plate 48, figs. 1-2; 1903, Bergens Museums Aarbog, No. 4, p. 12. This medusa is liberated from Podocoryne areolata of the British coasts. According to Browne, the medusa becomes about 4 mm. wide and slightly less in height. The bell is pyriform with a thick, gelatinous apex. There are 25 to 30 marginal tentacles about as long as the bell-radius and with fairly large basal bulbs which lack ectodermal ocelli, but have entodermal pigment. The stomach lacks a peduncle and is about one-halt to two-thirds as long as the depth of the bell-cavity. There are 4 long, narrow lips, each of which bifurcates and ends in 2 knob-like clusters of nematocysts. The gonads are upon the sides of the stomach. According to Browne, the entoderm of the stomach and tentacle-bulbs is rich reddish- brown, darker than the stomach. When set free from the hydrnid the medusa has 16 marginal tentacles of various lengths. Browne has not observed the hydroid, which was obtained by Alder. I am inclined to believe that this medusa may prove to be identical with Lymnorea borealis, found at Eastport, Maine, on the American Atlantic coast. In Europe it ranges from British coasts to Norway, and is rare according to Browne. Podocoryne octostyla. D\smorpliosa oe/ostvla, HAECKEL, 1879, Syst. der Medusen, p. 78, taf. 6, fig. 6. Bell 0.4 mm. high, 0.5 mm. wide, with bulging sides and low, conical apex. 8 short, equally developed, marginal tentacles, about as long as the radius of the bell, with small basal bulbs. Stomach mounted upon a conical peduncle as long as itself; both together about two-thirds as long as the depth of the bell-cavity. 8 simple, knobbed, oral tentacles about as long as the stomach. 4 swollen, interradial gonads on the sides of the stomach. When young, medusa-buds are produced upon the interradial sides of the stomach. Gonads and tentacle- bulbs nearly black. Found in the Mediterranean. Two specimens were found by Haeckel. Podocoryne polystyla. Cytaandra pol\st\la, HAECKEL, 1879, Syst. der Medusen, p. 79. Bell nearly cubical, 1.5 mm. wide, 1.5 mm. high. 32 short, marginal tentacles (without ectodermal ocelli ?). Stomach large, cubical, mounted on a short peduncle and filling nearly all of the bell-cavity. 16 short, simple, oral tentacles. 4 gonads on the lower part of the stomach-wall. The gonads are " halt-moon-shaped " with the convex side below. Stomach yellow. Gonads and tentacle-bulbs reddish-brown. Found by Haeckel at Croisic, Atlantic coast of France. Podocoryne minuta. Plate 14, fig. i. nismorpltosa minuta, MAYER, 1900, Bull. Mus. Comp. Zool. at Harvard College, vol. 37, p. 41, plate 18, fig. 42. Dvstnorpltosa minuta, TRINCI, 1904, Monit. Zool. Ital., Anno 15, p. 304. ( ) ( ,r.F/s minima, TRINCI, 1903, Mittheil. Zool. Sta. Neapel, Bd. 16, p. I, taf. I, fign. 1-30 (young medusa ?). Bell pear-shaped and only 0.3 mm. high. Bell-walls quite thick and the apex solid and bluntly pointed. In common with other species of Podocoryne, the gelatinous substance of the bell is very delicate and the medusa soon collapses into a shapeless mass when subjected to the abnormal conditions of captivity in a small aquarium. There are 8 solid, marginal tentacles with well-developed basal bulbs without ocelli. The velum is narrow. There are 4 straight, narrow radial-canals and a slender ring-canal. The manuhrium is mounted upon a short, wide peduncle, which is solid, and down the 4 radial corners of which the radial- canals extend into the stomach. The gastric portion of the manubrium is 4-sided in cross- section. 4 well-developed, oral tentacles surround the mouth. The entodermal cores of these oral tentacles are composed of chordate cells, and each tentacle terminates in a bristling. PLATE 16. Figs, i to 3. Podocoryne gracilis. Successive stages in the growth of the medusa. Tortugas, Florida, June, 1899. Figs. 4 to 5. Bougainvillia autitninalis, young and mature stages ot the medusa. Agassiz Laboratory, Newport, Rhode Island, Septem- ber, 1895 and July, 1896. Fig. 6. Bougainvillia fronJosa, showing planula; upon the sides of the stomach. Tortugas, Florida, June, 1897. Fig. 7. Koii^nlnvilliti carolinensis, young medusa. Agassiz Laboratory, Newport, Rhode Island, July, 1892. Fig. 8. Bougainvillia carolinensis. Cluster ot marginal tentacles of a young medusa from Newport, Rhode Island. Fig. 9. Bougainvillia carolinensis. Oral tentacle of a young medusa from Newport, Rhode Island. Drawn from life, by the author. PLATE 16 AXTHO.MKIH S.t — PODOCOK YNK. 141 knob-like cluster ot nematocysts. Several medusa-buds in various stages of development are found upon the sides of the upper interradial regions of the stomach. These budded medusae are set free as in P. fulgurans. In some specimens the entoderm of the manubrium and tentacle-bulbs is turquoise-blue and in others it is lilac. This medusa was abundant at Tortugas, Florida, in the middle of July, 1898, and Trinci finds a very similar medusa at Naples, Italy. I am inclined to regard Trinci's C.\t,i-n minima as the immature, 4-tentacled, medusa-budding stage of Podocoryne niniuta. According to Trinci the bell is pyriform, 0.27 to 0.33 mm. high and 0.2 to 0.24 mm. wide. 4 perradial, marginal tentacles, each as long as the hell-diameter, with well-developed basal bulbs without ectodermal ocelli. Manubrium and tentacles yellowish-brown with blue in the entoderm. Medusa-buds develop upon the 4 interradial sides of the manubrium. These budding medusae are formed entirely from the ectoderm of the parent medusa. Trinci in the following year found a medusa similar to the above, but with 8 marginal tentacles.. Excepting for a slight color difference this 8-tentacled medusa is identical with I', mi nut a from Tortugas, Florida. Podocoryne tenuis. Dysmorphosa tenuis, BROWNK, 1901, Annah and Mag. Nat. Hist., ser. 7, vol. 9, p. 277. (? ?) Podocor ynt liumilis (hydroid), HARTLAVR, 1905, Zoning. Jahrbuchern, Suppl. 6, p. 523, fig. i. Umbrella somewhat conical, 2 mm. high and 1.5 wide. There is a slight constriction above the level of the subumbrella cavity. 8 tentacles. Manubrium cubical and mounted upon a peduncle about as long as itself. Mouth with 4 lips having terminal clusters of nemato- cysts. Medusa-buds are found upon the interradial sides of the manubrium. (ionads not developed in the two specimens studied by Browne. Color ( ?) Found at Stanley Harbor, Falkland Islands. Briefly described without figures by Browne. This medusa appears to differ widely from the North American variety of Podocoryne i ni urn, but the hydroid described by Hartlaub bears a close resemblance to our North Ameri- can P. canifii. Hartlaub's hydroid may not be the stock of P. trntit>. however. Podocoryne dubia Mayer. Plate 14, figs. 7 to 9. D \smor phasa Jubiu, MAYLR, 1900, Bull. Mus. Cuinp. Zool. at Harvard College, vol. 37, p. 40, plate 21, figs. (14-66. Bell higher than a hemisphere, 1.5 mm. high and three-fourths-egg-shaped, with thin, uniform, flexible walls. There are 8 stiff", marginal tentacles which are club-shaped, being somewhat wider near their ends than they are near their basal bulbs. The outer extremities of the tentacles are thickly covered with nematocysts. Their basal bulbs are large and swollen, and a very large, black ocellus is found in the ectoderm ot the under side of each bulb (plate 14, fig. 9). The velum is well-developed. There are 4 straight, narrow radial-canals and a ring- canal. At the middle point in the length of each radial-canal there is a small, hernia-like swelling, which is probably glandular and similar in structure to the swollen parts of the radial-canals of Lymnorea alexanJn. The manubrium is pear-shaped, quite slender, and extends about half the distance from the inner apex of the bell-cavity to the velar opening. The mouth is surrounded by 4 short, radially situated, oral tentacles, each of which terminates in a bristling cluster ot nematocysts (plate 14, fig. 8). Cionads ( ?) The entoderm ot the manubrium and tentacle-bulbs is delicate custard-yellow. Only one specimen has been found. This was taken on the surface at Tortugas, Florida, on July 20, 1898. Podocoryne gracilis. Plate 1 6, figs, i to 3. C\i.rii gracilis, IWAYtR, njoo, Bull. Mu^. I'oinp. Zool. at Harvard College-, vol. 37, p. -,'i, plat.- -,'.. tig' . 11: 1:4. Dysmwphosa ^rarilis, MAAS, 1905, Craspedoten Medusen der 5jfro£d Expedition, Monog. 10, p. 8. Matur,- iiifJusa. — Bell pyriform or dome-like with a slight apical pro|ection. It is about $ mm. in diameter and a little broader than it is high. The gelatinous substance is of only moderate thickness on the sides, although it is about twice this thickness at the apex of the 142 MEDUS.E OF THE WOULD. bell. There are 8 stiff marginal tentacles with large basal bulbs. These tentacles are carried curled upward from the bell-margin. The 4 radially situated, marginal tentacles are about two-thirds as long as the bell-height, but the 4 interradial ones are only about halt of this length. The basal bulbs of all of the tentacles are large, swollen, and hollow, with their entoderm deeply pigmented. The velum is broad. There are 4 simple, straight radial-canals and a simple circular vessel. The stomach is mounted upon a short, wide, solid peduncle. The stomach and mouth-parts are together only about half as long as the depth of the bell- cavity. The mouth is a simple, round opening without prominent lips and is surrounded by 8 unbranched, oral tentacles, each of which terminates in a knob-like bristle of nematocysts. 4 of these oral tentacles are radial and 4 interradial in position. Their entodermal cells are chordate, and the nematocyst-capsules upon their free ends are spindle-shaped. Medusa- buds develop upon the 4 interradial sides of the stomach. When set free each medusa has only 4 short, equally developed, marginal tentacles. The 4 interradial, marginal tentacles do not develop until the medusa is about half-grown and after it has acquired 8 oral tentacles. The entoderm of the manubrium is usually red in color, although often the inner core is red or pink and the outer annulus of entoderm is green. Each tentacle-bulb is provided with a dense mass of red, entodermal pigment, which in the case of the radial tentacle-bulbs extends a considerable distance up the radial-canals. This medusa was quite common on the surface at Tortugas, Florida, in June, 1899 and 1907. This species and P. octostyla Haeckel are the only forms of Podocoryne having rrfore than 4 oral tentacles. The remarkably late development of the 4 interradial, marginal ten- tacles and the presence of more than 4 oral tentacles indicate the close relationship between C,\ticis and Podocoryne. In Cyttns more than 4 oral tentacles are the rule. Although the medusa appears to begin life with but 4, later it acquires 8 or more, Cyta-is vulgans having 32 tentacles. Podocoryne humilis Hartlauh. Podocor\ne liutnilis, HARTLAUB, 1905, Zoolog. Jahrbuchern, Suppl. 6, p. 523, fig. K. ( ?) D\stnorphosa tenuis (medusa), BROWNE, 1902, Annal. and Mag. Nat. Hist., ser. 7, vol. 9, p. 277. Hartlaub describes this hydioid from Terra del Fuego, and states that it may prove to be the stock of Podocoryne tenuis, which was briefly described by Browne, 1902, from the Falkland Islands. The polypites arise in groups from the hydrorhiza. The feeding polypites are about i mm. long, club-shaped, with narrow bases, and a short, conical hypostome, which is encircled by a single zone of about 12 filiform tentacles about half as long as the body of the polypite. The reproductive polypites are swollen, with only about 5 well-developed tentacles with a cylindrical proboscis, and with 3 to 4 large medusa-buds upon the basal half of the polypite below the zone of tentacles. These medusa-buds are mounted upon short pedicles, and when set free the medusae have no sexual products. The hydrorhiza forms an open net- work of thin branches bearing short, smooth, thorn-like processes. There are no spiral zooids or tentacular filaments. Color ( ?) Number of tentacles possessed by the medusa when set free ? Puerto Bridges, southern Terra del Fuego, January, 1893; from a depth of 7 fathoms. This species appears to me to be closely allied to, if not identical with, the Podocoryne of the coast of New England. The number of the tentacles is very variable in our New England Podocoryne, especially in the reproductive polypites, and the colonies range considerably in size, apparently being influenced in this respect by conditions of nutrition. There is nothing in Hartlaub's description to prevent our considering the species from the southern end of South America to be identical with P. cornea of the coast of New England. Podocoryne denhami Thornely. Podocoryne denhami, THORNELV, 1905, Roy. Soc. Report Ceylon Pearl Oyster Fisheries, vol. 2, p. no, plate I, fig. 6. Basal crust beset with numerous tall, stout, linear, reddish spines. Hydranths white, with about 24 tentacles on the barren ones, and only 4 or 5 on those bearing gonophores; and these latter are considerably swollen. A pair of large globule (medusiform ?) gonophores on each reproductive hydranth. Medusa unknown. Size ( ?) Growing on a shell of Murc\ in Polk Strait, Ceylon. ANTIIOMKDI S.K— -TVHKITol'SIS. I I.'! Genus TURRITOPSIS McCrady, 1856. OfCiiniti (Turritopsisjj M, iXiji. /,.,,il. Anzeiger, Bd. 14, p. 444.— BROOKS and RITTENHOI si, 1907, Proc. Boston Soc. Nat. Hist., vol. ;-,, p. 4;!.. \on Turritopsis, AGASSIZ, A., 1865, North Amer. Acal.. p. 167. The type species of this genus is T . nutrient a McCrady, 1856 -57, from Charleston I larlior. South Carolina. It is common in summer from the West Indies to the southern coast of New England. GENERIC CHARACTERS. Margelinae with S or more simple, marginal tentacles, which arise singly, not in clusters, from the bell-margin. The walls ot the 4 radial-canals, above the stomach, consist of highly- vacuolated, entodermal cells, forming a peduncle for the gastric part of the manubrium. The 4 lips are studded with nematocyst-hearing knobs. The gonads are developed upon the 4 inter- radial sides of the stomach. The hydroid is Dendroclava. Turritopsis is peculiar in the remarkable development of vacuolated, entodermal cells lining the courses of the 4 radial-canals above the stomach. This condition is also displayed to a limited degree by some, but not by all, ot the medusae of the genus Lymnorea. In Lv»i- nnrt'ii, however, the mouth is surrounded by branched, oral tentacles, whereas in Titrritnf»i> the lips display bead-like knobs of nematocysts, which I am inclined to regard as the remnants of the oral tentacles of the ancestral forms of Turritopsis. The tentacles of Turritopsis arc solid and similar in structure to those ot Lymnorea. There is an ectodermal ocellus upon the inner (axial) side ot each tentacle, adjacent to the basal bulb. In Tiannje, on the other hand, when ocelli are present they are found upon the outer fabaxial ) sides ot the tentacle-bulbs. On account of the close similarity between the tentacles of Turritopsis and those of (),,,inin, Lymnorea, Podocoryne, Cytteis, znd Cubogaster, we incline to Vanhbffen's (1891) view that T urritopsis is related to the Margelinae rather than to the Tiarina.-. Turritopsis is closely related to Oceania, but is distinguished by its \acuolated peduncle, that of Ofcanta being solid and gelatinous. Turritopsis nutricula McCrady. Plates 14 and 15, figs. 10 to I}. Oftania (Turritopsis) tiutricula, McCfiAuv, 1856, Proc. Elliott Soc. Charleston, pp. i-;6, plate 4, figs, i -10. Turritopsis nulricula, MiCRADY, 1857, Gymn. Charleston Harbor, p. 25, plate 8, fig. i .— BROOKS, iSS;, studies Johns Hopl.m Univ. Biol. Lab., vol. 2, p. 465. — BROOKS 1886, Mem. Boston Soc. Nat. Hist., vol. ; p. ;SS. plate ;?. -HAROITT, 1904, Bull. I'. S. Bureau of Fisheries, vnl. 24, p. }7 (the figure is I3odo(or\nt earned). — Rm'tNiMH s>, M>O^, Pnn . Ii.i'f.,n s.,, . Nat. Hist., vol. 33, p. 437, plates 30-35, figs. 1-55 (development). .U"./L, 187"). S\st. dcr Mi'ilusen. p. (>tt. Turrilrjptrs f>rjl\'t irrlia, HARTLAUB, 1897, Wis.sen. MecresunterMiili . K "1111111 .. MI rr< Kir I, H<-|L;"|,UI.|. \' ur I "lee, Bd . 2, p. 480, taf. l6r, fig. 2. ( ) r\/,r/.t /)d/v5/\//;, \\'N.I., 1844, Hone Tergcst in.r, p. 68, taf. 2, fig. V. .•hncriian IHK/HSH ( plate 14, fig. 10). — Bell usually slightlv pvritorm and about 4 to , mm. in height. Bell-walls uniformly thin. There are 40 to 70 simple, marginal tentacles, which are all ot about the same length and are somewhat shorter than the bell-height. T hese tentacles are capable of much contraction or extension. Their basal bulbs are large and there is a single, ectodermal pigment-spot upon the lower (centripetal) side of each tentacle near its place of origin from the basal bulb. The surface of the tentacles i> co\i-ied thickly with nematoc\st- cells. The velum is well developed. There are 4 straight, narrow radial-canals and a narrow circular vessel. The manubrium is large and fills about halt of the bell-cavity. The upper 144 MEDUS/E OF THE WORLD. part of the manubrium near the base consists of 4 radially situated masses of large, highly vacuolated, entodermal cells, through the midst of which the 4 radial-canals extend downward into the stomach. These cells are indeed only the entodermal walls of the radial-canals (plate 14, fig. 13). The stomach is large and quadratic in cross-section. The cruciform mouth is situated at the extremity of a short neck and is surrounded by a row of nematocyst-bearing knobs (plate 15, fig. 12). The gonads are developed upon the sides ot the stomach, where they occur in the form of a double, longitudinal, swollen region in each adradius. Their outer surfaces are smooth. The entoderm of the stomach is dull-yellow or orange, or dull- vellow streaked with orange. The tentacle-bulbs sometimes contain a little entodermal orange pigment. The ocelli upon the tentacles are dark-brown or orange. Hydroid and young medusa. — The hydroid (fig. 76) was found by Brooks, 1883, on piles of a wharf at Morehead City, North Carolina. It is a Dendroclava and closely related to D. dohrnii Weismann. The stems of the hydroid are from 8 to 10 mm. in height and bear large, terminal hydranths. There are also numbers of short, side branches which terminate in hydranths. The main stem and the side branches are incased in a loose, cylindrical pen- sarc, which is thick and becomes mcrusted with foreign matter. The pensarc is not an- nulated, and terminates abruptly by a sharp collar immediately below each hydranth. The hydranth or feeding-polypite is long and fusiform and bears from 18 to 20 short, thick, filiform tentacles, which are arranged in three or more indefinite rows or whorls. The medusa- buds originate upon the sides of the stem at the bases of the hydranths. Each medusa-bud is borne upon a short stalk or peduncle and is closely invested by a thin capsule of perisarc. When set free the young medusa has 8 tentacles. The manubrium is cone-shaped and there is a large peduncle formed of highly-vacuolated cells. 4 prominent, nematocyst bear- ing knobs surround the mouth. The hydranths are pale yellowish-red. This medusa is found from the coast ot Cuba to the southern coast of New England, being about equally abundant in the northern and southern limits of its range. It is very common in the Bahamas and at Tortugas, Florida. In Charleston Harbor, South Carolina, it is commonly infested by larvae of Cunoctantha octonaria McCrady, although it appears to be quite immune from this parasite in other places. I can detect no specific distinctions between this medusa and "Turntopsis [>ol\- cirrka," which is occasionally seen off the Atlantic coast of France and German}'. This form is well figured by Keferstein, 1862, and Hartlaub, 1897, who are the only European students who have observed the medusa on the eastern side of the Atlantic. Rittenhouse, 1907, has made an elaborate study of the development of T. nutricula. The ova develop in the ectoderm of the 4 interradial sides ot the manubrium. The primitive ova grow by the absorption ot ovarian cells around them, as is common in other hydromedusae. The yolk-spheres in the ovum are formed from the ovarian cells which it absorbs. About 20 to 35, rarely 50 or more, eggs are discharged into the water by the muscular rupture of the ovar- ian walls between 5 and 6 o'clock in the morning. The discharged eggs are spherical, o.i 16 mm. in diameter and have no membrane. They are yellowish-white, heavier than sea-water, and opaque. The outer layer of finely-granular ectoplasm is distinct from the coarsely gran- ular, yolk-laden endoplasm. Soon after being discharged the egg gives off two polar bodies and is fertilized. Segmentation is total and approximately equal. The first two segmentation planes are meridional and the third equatorial. The blastomeres remain quite far apart, touching only slightly. After this the cleavage becomes remarkably irregular, recalling the extraordinary condition observed by Hargitt in Pennaria. A solid morula is formed, which has no central segmentation cavity and which resembles a loosely-connected mass of irregularly grouped cells rather than an embryo of any metazoan. The cleavages follow one after another at intervals of 20 to 30 minutes. I''K,. 75. -Turrtlopm nutrtculti, after Brook Mem. Boston Soc. Natural History. ANTHOMEDUSiE— TUBRITOPSI8. 145 As in MetschnikofF's <>,,,iin. (') = (0ceania polycirrha), after Keferstein, 1862, Zeit. fur wissen. Zool., Bd. 12, uf. 12, fig. n. Rittenhouse finds that during the early stages ot cell-division in Turritopsis the multipli- cation is solely by mitosis, but that later, when the embryo becomes a mere irregularly arranged mass of loosely-compacted cells, some of the nuclei divide amitotically. When about 50 hours old the elongate, oval larva ceases to swim through the water and settles down upon its side on the bottom. The larva then becomes the hydrorhiza, or root, of the hydroid, and the first hydranth arises as a bud from about the middle of its length. The tentacles of the hydranth develop in indefinite whorls, with 4 tentacles in each whorl, the oldest tentacle being nearest to the mouth. In the mature hydroid the tentacles appear to be irregularly scattered rather than being arranged in whorls. Turrrtvpsts should he reared under more natural conditions than those of the ordinary laboratory in order to determine whether the remarkable, irreg- ularly formed embryos described by Rittenhouse be normal or merely the result of pathological states induced by adverse conditions; but Miss Beckwith has recently shown that the cleavage of Pennarta is normally irregular as is described by Hargitt. Rittenhouse finds that when the embryo is in the loose-celled, morula stage it may be divided into two masses, each one of which produces a normal planula larva of small size. Turritopsis (?j lata von Lendenfeld. Tuiritafsis lata, VON LENDENFELD, 1884, Proc. Linncan Soc. New South Wales, vol. 9, p. 588, plate 22, figs. 36, 360. ( ? ?) Mrlirerla pleurostoma, PERON ET LESUEUR, 1809, Ann. du Mus. Hist. Nat., Paris, tome 14, p. 353. Mature medusa. — Bell 3.5 mm. high, 3 mm. wide, with a low, dome-like, apical projection. 60 to 130 marginal tentacles about as long as the bell-height. These have well-developed basal bulbs, and there is an ocellus on the inner (velar) side of the base of each tentacle. Velum well developed. 4 broad, straight radial-canals. The manubrium is mounted upon a peduncle, but von Lendenfeld does not state whether it be composed of vacuolated, entodermal cells or of the gelatinous substance of the bell, and his figures are too vague to throw any light upon this point. Until this is settled we can not determine the systematic position of this medusa. The stomach is spindle-shaped, about two-thirds as long as bell-height. The mouth does not extend to the velar opening, and there are 4 lancet-shaped lips which are recurved and one-third as long as the manubrium. These lips have stalked nettling warts on their margins. There are 4 protruding gonads on the stomach-wall, each one being one-fourth spherical in shape. Gonads and entoderm of tentacle-bulbs intensely brown. Ocelli red. This is the most abundant medusa in Port Jackson, New South Wales, during the Aus- tralian summer and autumn. The young medusae have but 4 marginal tentacles. Genus OCEANIA, sens. Kolliker, Gegenbaur. Oceania (in part), PERON ET LESUEUR, 1809, Annal. du Mus. Hist. Nat. Paris, tome 14, pp. 344-347. Oceania, KOLLIKER, 1853, Zeit. fiir wissen. Zool., Bd. 4, p. 323. — GEGENBAUR, 18^6, Zeit. fur wissen. Zool., Bd. 8, p. 223. — KEFERSTEIN UND EHLERS, 1861, Zool. Beitr. Messina, p. 83. — METSCHNIKOFF, 1886, Embryo). Studien an Medusen, Wlen, pp. 23, 25, etc., to 78. Turritopsis (in part), HAECKEL, 1879, Syst. der Medusen, p. 65. (>)Modecria (young medusa), FORBES, 1848, British Naked-eyed Medusa-, p. 70. Modteria-'r Callitiara, HAECKEL, 1879, Svst. der Medusen, pp. 47, 48. Occania=CalIiliara, VANHOFFEN, 1892, Verhandl. Gesell. Deutsch. Naturf. Arztc, 64 Vers., Abth. Syst.. p. 121. The generic name "Oceania" of Peron and Lesueur has no definite modern meaning, for it was applied to many medusae belonging to the Eucopidae, Tiarinae, Thaumantidae, etc. In 1862 "Oceania" was restricted by L. Agassiz to apply to a genus of the Eucopidae, but this same genus had already been named Phialidium by Leuckart, 1856, and thus Agassiz's ANTHUMKIH > I. <>< KAMA. genus Oceania loses precedence. The type species of Oceania in the modern sense is O. ariniita of the Mediterranean. It is possible that one of Peron and Lesueur's descriptions refers to this medusa (i.e., Oceania flaviJula?), but I am in much doubt upon this point. We must fall back upon Kolliker, 1855, and Gegenbaur, 1856, for the definition of Oii-nnin in the modern sense. Haeckel suppresses (),,-, nun and merges it with T nrritnpsis, but in Oceania the peduncle is simple, solid, and gelatinous, whereas in McCrady's T nrrit't[»i<; it is composed of large. vacuolated cells. GKNI-RK t H \i< UTKRS. Margelinje with 8 or more marginal tentacles which arise singly from the hell-niaruin. and are not grouped in isolated clusters. There are ectodermal ocelli on the inner i \elai i sides of the tentacle-bulbs. The mantibrium is mounted upon a simple, solid, gelatinous peduncle. The 4 lips lack oral tentacles, but their margins are lined by a row of wait-like nematocysts. The hydroid is clava-like. Following the lead ot Agassrz, it has been the custom of American students to define Oi i uniii in a sense equivalent to PhniliJium of Leuckart, but as we ha\c seen I'/miliJiuin, 1856, clearly takes precedence over Agassiz's Oceania, 1862. In the system here proposed the genus Oceania falls among the Oceanidx instead of being among the Eucopidae as it would be were Agassiz's definition admissible. FIG. 78. — "MoJrrria joTtno'a" after Forbes. FIG. 79. — Oceania "faviitult" (O . armata), after Gegenhaur, in Zeit. fur «i en. /.<"> nenc name Modeena Forbes, 1848, was applied to a very voi . y.ooi., Bd. 8. I he generic name Modecria Forbes, 1848, was applied to a very young and immature medusa which is so vaguely described that we can not state whether or not it had ectodermal ocelli. I consider that the name Modecria had best be dropped, having already led to nearly endless confusion. The genus Oceania is closely related to Turritopsis, but is distinguished by its simple, solid, gelatinous peduncle; whereas the peduncle in Turritopsis is composed of a mass of vacuolated entodermal cells. Oceania armata Kolliker. ( ?) Moiieertu forrnottl (young mrihisa), l-'oKli^, |S4S. Unti^i Naked-eyed M'- lir,,i', p. 70, pl.itr 7, tii;. I. Oceania armala, KCILI.IKF.R, 185^, Zoit. fur \visM-n. 7-o.il., BJ. 4. p. -,2',. — M ITSI nMKot \ , iSSd, Kinlirynl. Stiulii-n an Mnlu rn. \\'ifn, p|i. 2^, 25 (egg); 36, 37, 47 (segmentation); 75, -S (development of hydroid). Offtinia ftartttula, GEGENBAUR| 1856, Zeit. fur uissen. Xoo] ., It, I. X. p. 12:;, taf. 7, fig. 4. KSJIRMMN i MI l^nifks. 1861, Zoolog. Beitragc, p. 83, Lrip/ii;. -SpAciNoi.INI, 1876, Atti Soc. Ital. Sci. Nat., tome 19, p. 22, lav. ;, fig. 3. Pandea fliiridttla, A(;ASSIZ, L., 1862, Cont. Nat. Hi.st. I1. S., vol. 4, p. ^4-. • Turritopsn armala, HAM'K'F.L, 1879, Syst. der \fetlusen, p. 65. t'.allitiata polyopthalma, HAM KM, 1X71), Svst. Jer Metlust-n, p. i\-j, taf. 3, fign. 1-5. Tiarella parthcnnpia, TRINCI, 1906, Monitore Zoologico Ital.. Anno i^, p. ioK, 2 figs. Bell pyriform, flat-topped, higher than a hemisphere, with uniform, thin walls. 8 to 10 mm. high, 8 to 10 mm. wide, no to 100 or more slender, tapering, marginal tentacles. 1.5 times as long as the bell-diameter. 1 hese tentacles are crowded into a double row. Their 148 MKDUS.E OF THE WORLD. entoderm is solid and composed of chordate cells. There is an ectodermal ocellus on the velar side of each tentacle-bulb. Velum well developed. Well-developed circular muscles in the subumbrella. There are 4 jagged-edged, slender radial-canals and a simple ring-canal. The stomach is flask-shaped, cruciform in cross-section and mounted upon a short, pyramidal, 4-sided peduncle. This peduncle is a solid, gelatinous, truncated pyramid, only about one- third to one-fifth as long as the stomach itself. It is not vacuolated as in Turntopsis. The 4 lips are large and recurved and extend to the middle of the bell-cavity and their edges are studded with a single row of knob-like nematocyst-warts. The 4 gonads are developed upon the interradial sides of the stomach and are longitudinal swellings with smooth outer surfaces. The stomach and gonads are yellow or brownish-yellow. Eggs pearly-white. Lips red- dish-yellow, or port-wine colored. Radial-canals, ring-canal, and tentacles milky-yellow. Ocelli reddish-brown (see fig. 91). Found in the Mediterranean. Ouite common at Naples. (See figs. 78-81.) Vanhoffen (1902, Verhandl. Gesell. Deutsch. Naturf. Arzte, 64 Vers., Abth. Sitz., p. 121) maintains that this medusa is identical with CuUtttara polyopthalma Haeckel of the Canary Islands, and with this I am in accord, having seen many specimens of the living medusa at Naples. Trinci, 1906, describes a medusa from Naples which resembles O. armata in all respects excepting that he finds no ocelli. He studied preserved specimens, however, and FIG. 80. — Oceania. "Callitiara polyophlhthalma11 (Oceania armata), after Haeckel, 1879. the ocelli may have faded. As Gegenbaur states, the ocelli upon the inner sides of the tentacle- bulbs recall the conditions seen in Bougainvillia, and oblige us to place the medusa among the Margelinae. In the Tiarinae, on the other hand, the ocelli when present are always on the outer, abaxial sides of the tentacle-bulbs. Gegenbaur (1854, Zur Lehre von Generationswechsel, p. 28, taf. 2, fign. 10-16) reared the larva from the egg, and later Metschnikoft carried out a similar series of studies. Metschmkoft, 1886, finds that the egg of this medusa is milky-white and 0.28 mm. in diameter. It is laid between 6 and j o'clock in the afternoon during December, in the Medi- terranean. The segmentation is total, but not equal, and the resulting blastomeres form a very irregularly shaped, i-layered mass, inclosing a large segmentation cavity. Finally, a symmetrical, egg-shaped, ciliated, planula larva is formed. The planula attaches itself and becomes a branched hydrorhiza, from which the spindle-shaped clava-like hydranths arise. These develop in about 18 days after the egg is laid. The polypite has 13 tentacles arranged alternately in 3 whorls. In its irregularly shaped larva and in its mode of attachment this medusa resembles Turritopsis, to which indeed it is evidently closely related, the only distinction between Turritopsis and Oceania being that in the former the peduncle is vacuolated and in Oceania it is solid and gelatinous. .\\THO\IUH s ]•: STYI.AI TIS. 1 10 Genus STYLACTIS Allman, 1864. Slylaclis, ALLMAN, 1864, Annals anil Mag. Nat. Hist., scr. 3, vol. 13, p. 353; 1871, Monograph TubuUnan Hy>lroi,l;,, p. 301. CLARKF., 1882, Mem. Boston Sue. Nat. Hist., vol. 3, p. IjS. SH.IKHIOS, iSSi), American Naturalist, vol. 33, p. 801. These are Margelinae in which the medusa is degenerate, and indeed in the European species of Stylactis no medusae are set free, mere sporosacs being developed on the hydranths. The two American forms, however, produce free-swimming, although degenerate medusae. The medusa has 8 rudimentary tentacle-bulbs, 4 radial and 4 interradial ; 4 simple radial- canals and a ring-canal. The manuhiium is sac-like without a mouth, and without oral tentacles. The gonad encircles the sac-like manubrium, and the mature eggs or spurn arc- found in the ectoderm. The sexes are separate. The hydroid, Stylactis, hears a resemblance to hoth HyJractinia and Podocoryne, hut unlike the two last named the hydrorhi/.a is not covered with a fleshy layer of cu-nosarc c Flf lip, '., velum ; ov., ova. X 50. The bell is somewhat killer than a hemisphere, with thin, uniform walls. There are 8 short, marginal tentacles, 4 radial and 4 interradial. The velum is well developed. There are 4 straight, slender radial-canals and a ring-canal. The manubrium is wide and spindle- shaped and fills the greater part of the bell-cavity. There is no mouth-opening and there are no oral tentacles. The ectoderm around the middle region of the manubrium is much distended with the genital products. Hydroid. — The hydroid was found by Sigerfoos growing upon the living shells of Ilyanassa, especially upon snails found crawling upon eelgrass. It was found in Lloyds Harbor, Huntington Bay, in Long Island Sound, New York, during the summers of 1898 99. ANTHOMKOrs.K STVI. UTIS, TH \ M \( ISTV I.I'S. I .") I There is no hydrocaulus. The hydrorhiza is a network of tubes lying in one plane, from which arise a tew small, simple spines and many sessile h\ dranrhs. The hydranths are of two kinds, nutritive and reproductive. The nutritive hvdranths are ahout 25 mm. long and are elongate, simple, and unbranched. Their oral ends taper gradually, being widest at the circlet ot tentacles. There are usually about 20 long, slender tentacles arranged in a single whorl, but specimens are found with as many as 35 and as few as 15 tentacles. The entoder- mal cores of these tentacles are solid and consist of a single row of cells. The tips of these tentacles are not appreciably swollen or knob-like, although they are well provided with nematocysts. The reproductive hydranths are slightly smaller than the nutritive ones. They have only 6 to 10 tentacles and are only one-third to three-fourths as long as the nutritive hydranths, but they have functional mouths. 1 here are usually 4 to 5 medusa-buds arranged in a circlet immediately below the circle of tentacles. The entoderm of the hydroid is white or pinkish- white. The medusae appear to be set free soon after dark, and the breeding season extends throughout July and August. There are no spiral protective zooids such as are found in Hydractinia and there is no coenosarc layer over the hydrorhiza such as is found in H \Jrtu tnnn and l)'iJ(n-r>r\>if. Stylactis arge Clarke. Xijiiilis argt, CHRKK, |S82, Mem. Boston Soc. N.u. Hi^t., \.,l. ;, p. i ^K, plate 8, figs. 18-20. The medusiform gonophores of this species often become mature while attached to the hydroid stock. In other cases, however, the gonophores become free, although they are sexually mature at the time of liberation. hit-f medusa. — The bell is ellipsoidal and the gelatinous substance thin. There are 8 small rudimentary tentacle-bulbs, 4 radial and 4 interradial. 4 simple, narrow radial-canals. 1 he manubnum is globular and greatly distended by the contained genital products. Hydroid. — The hydranths are very much elongated and slender. Kach Indranth is provided with 10 to 30 tentacles which arise in 2 circlets close together below the lupostome. The tentacles ot the lower circlet are somewhat shorter than those of the upper one, although in some individuals all ot the tentacles are of equal length. There are usually 4 sporosacs or medusa-buds developed upon the sides ot the body ot the hydranth beneath the circlets of tentacles, 2 being first developed on opposite sides ot the hydranth, and then 2 others appear at points 90° from the first pair. The entire colony is of a delicate opaque white. It is remarkable that in this species a constriction sometimes appears around the hodv ot a hydranth, from a point just above which two or three cylindrical, stolon-like processes are developed. The constriction then becomes complete and the distal end ot the hydranth becomes tree. This then settles down in a new locality and the stolon-like processes give rise to a hydrorhiza and a new colony is thus developed asexually. This species has been found by Clarke in Chesapeake Bay. Genus THAMNOSTYLUS. Thardnostylut, H\K KM., 1X74, Syst. »lrr iUfilusrn, p. S^; iSSl, Rrpnrt H. M. S. ('.ltlill-'n ^ •> • . '/.•»'}., \ol. 4, p. z. The only known species is Thamnostylui Jnh'nni llaeckel, from the Antarctic Ocean. GKNKRIC CHARAC I I RS. Margelinz with branched oral tentacles and 2 marginal tentacles iSo" apart. Develop- ment unknown. Thamnostylus dinema Haeckel. Thamnostylui ; iXSi, Report H. M. S. (:imll>-ny, /.o<,l., vnl. 4, p. 2, pl.itr i, 8 figs. Bell hemispherical, ] besprinkled with isolated nettling cells. 2 diametrically opposite, radiall) situated, hollow. 152 MEDUS.E OF THK WOULD. marginal tentacles about 3 times as long as the bell-diameter and ringed at frequent inter- vals with swollen masses oi" nematocysts. The basal bulbs of these tentacles are swollen and conical and each one bears a dark-red abaxial ocellus. There are 2 rudimentary, ocellated tentacle-bulbs upon the margin 90° apart from the long tentacles. Velum wide. 4 straight, narrow radial-canals and a simple ring-canal. The stomach is a wide, 4-sided pyramid, as long as the depth of the bell-cavity. It extends below into a 4-sided, elongated throat-tube, twice as long as the stomach itself. This throat- tube projects beyond the velar opening and the mouth is a simple, 4-sided opening studded with nematocysts. 4 large, radially placed, oral tentacles arise from the distal end of the stomach and branch dichotomously 6 to 8 times, their ends terminating in nematocyst-knobs. The gonads are swollen, leaf-like, lobular, folded ridges in the 8 adradii of the stomach. They are blunt above, but more pointed below, and each gonad exhibits about 5 double transverse folds. The ova are prominent. The gonads, oral tentacles, nematocysts of bell-margin and of the tentacles and tentacle-bulbs are blood-red. Antarctic Ocean, south of the Kerguelen Islands, at a depth of 120 fathoms. Beautifully figured by Haeckel, 1881. Genus THAMNITIS Haeckel, 1879. Thamnitis, HAF.CKEL, 1879, Syst. der Medusen, p. 84. — VANHUFFF.N, 1891, Zool. Anzeigcr, Bd. 14, p. 444. — BROWNE, 1905, Proc. Royal Soc. Edinburgh, vol. 25, p. 758. The first described species of this genus is Thamnitis nigritella, first made known by Forbes, 1848, under the name Bougainvillea nigritella. The first species mentioned by Haeckel is a newly-described form, Thamnitis tctrclla. T. nigritella comes from the Shetland Islands, while T . tctrclla was obtained off the coast of Brazil. GENERIC CHARACTERS. Margelinae with branched oral tentacles and 4 simple, radially placed, marginal tentacles. It is possible that Thamnitis may be simply an immature or damaged Bougainvillia which has lost all but one marginal tentacle of each radial cluster, but we are not yet justified in concluding that this is the case. Forbes, 1848, describes and figures the tentacle-bulbs of Thamnitis nigritella as being bean-shaped, containing a single large ocellus ( ?) or mass of very dark pigment, and having a single short tentacle arising from one side of the bulb, not from the middle. Haeckel, 1879, p. 84, describes T. tctrclla as having small, pear-shaped ten- tacle-bulbs with a single tentacle arising from the middle of each bulb. He does not mention ocelli, but his description is brief and unaccompanied by a figure. Further study is required before we can be certain that T hamnitis actually exists in nature. Vanhoffen, 1891, accepts it with some hesitation, and I share his view in this respect. Browne, 1905 (Proc. Roy. Soc. Edinburgh, vol. 25, p. 758), is the only recent author who has seen a specimen of Thamnitis. He found two small, immature medusae in the Firth of Clyde, Scotland, in September to October. They were I to 1.5 mm. wide and had 4 simple, marginal tentacles. No ocelli. 4 oral tentacles 2 to 3 times dichotomously branched. No gonads. Stomach yellow to orange, tentacle-bulbs orange. "Thamnitis nigritella" Forbes, 1848 (British Naked-eyed Medusae, p. 63, plate 12, fig. 2) is probably an immature Bongainvillia which has lost all but one tentacle in each marginal cluster. Thamnitis tetrella Haeckel. Thamnilii lelrel/a, HAECKF.L, 1879, Syst. der Medusen, p. 84. Bell egg-shaped, being 6 mm. in height and 4 mm. in diameter. There are 4 radially situated, marginal tentacles which are longer than the bell-height. Each tentacle arises from the middle of a large basal bulb. An ocellus is situated at the base of each tentacle. There are 4 radial-canals. The manubrium is cubical with a wide quadratic base. There are 4 radially situated, oral tentacles, each of which branches dichotomously three times. The gonads are found in 4 interradial ( ?) swellings upon the wall of the stomach. Color ( ?) This species is found upon the coast of Brazil. ANTHOMKWS.K I.V\1\( HtKA. 1~>:! Genus LYMNOREA P«ron et Lesueur. ( ?) Fnfonia, PERON FT LCSIIKUR, 1809, Hist. Gen. des Meduses, p. 16. Lymnorea, PERON KT LESUEI'R, 1809, Ann. Mus. Hist. Nat. Paris, tome 14, p. 329. — DE BHINVIM i, 1834, Manuel il'Actim.l., p. 290. — MAYER, 1900, Bull. Mus. Cmnp. Zool. at Har\ard College, vol. ',7, p. 6; 1904, Mem. .N.n. Su. Brooklyn Inst. Museum, vol. i, p. io.— Ar.ASStz and MAVER, 1902, Mrm. Mus. Gimp. Zool. at Harvard College, v..l. i(,. p. 144. Limnorra+ Thaninmtonui, HAKTKM-, 1879, Syst. der Medusen, pp. 85, 86. l.tmnurfu^- Thomiiiutoma, VANHOFFEK, 1891, Zool. An/eiger, Bd. 14, p. 445. MiHtadia, BROOKS and RlTTENHOUSE, 1907, Proc. Boston Soc. Nat. Hist., vol. 33, p. 437. The oldest species of this genus is l.\tnnur,-a tri,;im, described by Peron and Lesueur, and first figured by de Blainville, 1834. It occurs on the southern coast of Australia. The figures and description leave much to be desired, but the branching oral tentacles are clearh represented. Tht- marginal tentacles are small and numerous. GENERIC CHARACTERS. Margelinx with branched oral tentacles and with 8 or more marginal tentacles which arise separately, not in clusters, from the bell-margin. The hydroid is unknown. Haeckel, 1879, would call medusae with 8 marginal tentacles Thamnostoma, and those with 16 or more Lnnnori-u. He introduced the spelling Limnorca, but Peron and Lesueur spell it Lymnorea. Owing to the very incomplete description of Peron and Lesueur it is impossible to determine whether Favonia is or is not equivalent to Lymnorea. Judging from de Blamville's, 1834, copy ot Peron and Lesueur's unpublished figure, it appears to be closely allied to Lymnorea, but its relationships must remain uncertain, l-'tivnnia takes precedence over Lymnorea, should it be equivalent, for it precedes Lymnorea in Peron and Lesueur's description. Lymnorea dibalia. Liszia dibalia, BUSCH, iSijl, Beohach. wirbellos. Seeth., p. 23, taf. 1, fign. 7-9. Ttiumnostomti dibaJis, HAEOKEL, 1879, Svst. der Medusen, p. 86. — GRAEFKE, 1884, Arbeit. Zool. Inst. Wien., Bd. 5, p. 348. Hell oval, 7 mm. high, 6 mm. wide. 8 marginal tentacles, those at the bases of the 4 radial-canals being longer than the 4 interradial tentacles. The ocelli are borne upon pro- jections, one ot which arises from each tentacle-bulb. The stomach is cubical and lacks a peduncle, and the throat-tube is as long as the stomach. There are 4 oral tentacles which branch dichotomously twice. 4 swollen gonads on the interradial sides of the stomach. Found at Trieste, Adriatic Sea, Mediterranean. Graefte states that the mature medusje are found in October, and the young first appear in September. Lymnorea macrostoma. Thamnostoma rnacro<.tomti, HAK'KH , iSy9, Svst. der Medusen, p. 86. Hell cubical, 8 mm. high, 8 mm. wide. 8 similar marginal tentacles, each longer than the bell-diameter. A simple, abaxial ocellus at tin- base ot each tentacle. Stomach globular with- out a peduncle. The throat-tube is 3 times as long as the stomach and extends beyond tin- velar opening. There are 4 short, oral tentacles, each of which branches dichotomously o to 8 times, thus giving rise to 80 to IOO terminal branches in each (jiiadrant. 4 gonads on sides of Stomach. Color ( ?) Indian Ocean, Singapore. Lymnorea ocellata Agassiz and Mayer. Lymaorea afdlntti, At,\ssi/., A., and MAYER, 1902, Mem. Museum Comp.Zool.al Harvard CoU*i vol. 16, p. 1441 plate 2, figs. 9-11, ( ') I.ymnorfa Iritdra, Pi KON tr I.tsi n R, 1X09, Anna), du Mus. Hist. Nat. P. ins, tome 14, p. 521); dc- Bl.niu ille, lH)4, Man. Actinolnt-H-, p. 2(jo, plate 40, fig. 2; HAH KM, lS79, Svst. der MrditM-n, p. 87. ( •) l.imrtorea probosciitfa, HAFCKM, iS?, figs. 16-18, plate 5. ( ;} Limnorea tioivegica, BROCH, 1905, Bergens Museums Aarbog, No. 11, p. 5. (?) Cvttftinda nreolala, BROWNF., 1897, Proc. Zool. Soc. London, p. 817, plate 48, figs. I, 2. (Podocorvtif!') Bell 3 mm. high. It is higher than a hemisphere and is acorn-shaped, with a low, blunt apical projection. The bell-walls are thin. There are 32 marginal tentacles, each about halt as long as the bell-height. They are quite stiffand are carried curled upward, above the margin. Their basal bulbs are large and densely pigmented. The velum is well developed. There are 4 straight, narrow radial-canals and a slender, simple, circular vessel. The manubrium is slender and pyriform and mounted upon a very short, solid peduncle. It is cruciform in cross- section. The mouth is flanked on its 4 radial corners by 4 short dichotomously branching oral tentacles (plate 15, fig. 2). Each oral tentacle branches dichotomously twice, thus giving 4 tentacle tips in each quadrant. These tentacle tips are knob-like and armed with long spindle- shaped nematocysts (plate 15, fig. 3) very much as are the oral tentacles of Lymnorea ocellata. The 4 gonads are found in four longitudinal, interradial, swollen regions in the ectoderm of the stomach-wall. The immature eggs are transparent and give a reticulate appearance to the surface of each gonad. The entoderm of the manubrium and tentacle-bulbs is bright-red. There are no ocelli. Three specimens were taken on the surface at Eastport, Maine, on September 19, 1898. Broch, 1905, gives a brief description of a Lymnorea from the coast of Norway which may be identical with this species. He states that there is a pair of very short, oral tentacles at each of the 4 corners of the mouth and that each of these forks dichotomously twice, thus giving 8 terminal knobs at each radial corner of the mouth. There are 16 to 22 tentacles. In other respects his description accords with that of/,, borealis, allowance being made for contraction due to preservation in Broch's specimen. He gives no figures and does not mention the color. Lymnorea alexandri Mayer. Plate 15, figs. 4 to 9. Lvmnorea ale\andri, MAVF.R, 1906, Mem. Nat. Scj. Museum Brooklyn Institute, vol. i, p. 10, plate I, figs. 1-5*7. M.ir.i.lm, i/)., BROOKS an. I KITTKNHOHSF., 1907, Proc. Boston Soc. Nat. Hist., vol. 33, p. 435, plate 31, fig. 8. ANTHOMEDUSjE— r.VMXoltr.A, BOUQAINVILLIA. Bell 4 mm. high, 3 mm. broad, with vertical sides, flat top, and thin walls. 32 slender ten- tacles with tightly coiled ends and large basal bulbs. A black, ectodermal ocellus lies upon the velar side ot each tentacle-bulb ( plate I 5, fig. g). The velum is well developed. The 4 radial- canals are straight and slender, but slightly swollen in the mid-region of their lengths, where their inner sides are lined with gland-cells (plate i 5, fig. 6). The manubrium is flask-shaped, and about halt as long as the depth ot the bell-cavity. The distal part of the manubrium ad- jacent to the points ot entrance ot the 4 radial-canals is composed ot highly vacuolated cells. The mid-region ot the manubrium is cruciform in cross-section and the mature genital pro- ducts are found in the ectoderm ot the 4 interradial sides of the stomach. The mouth is at the extremity ot a short neck and is surrounded by 4 oral tentacles, each ot which branches dichot- omously ^ rimes and terminates in 8 nematocvst-beanng knobs, making in all 32 ot these knobs surrounding the mouth (plate i 5, fig. 5 ). The entoderm of the manubrium and tentacle- bulbs is dull, flesh-colored pink. In the youngest medusa seen the bell was O.(> mm. in diameter and had only 4 oral tentacle-knobs, 4 marginal tentacles, and 4 rudimentary tentacle-bulbs. This is one ot the most abundant medusae upon the surface in summer, among the Bahama Islands. A single specimen was found at Tortugas, Florida, in July, igo5. Named in honor of Dr. Alexander Agassiz. Genus BOUGAINVILLIA Lesson, 1836. Cvan[>o(rene, BRANDT, (Mertens), 1835, Mem. Acad. Imperial)- des Sci. St. Petersliourg, Sci. Nat., SIT. 6, tome 2, p.22i). -Pre- occupied by OKEN, 1X17, for Mollusca.- -Ac.ASSiz, L., 1849, Mem. Amer. Acail., NYu Strie--, vol. 4, p. 250. Bougainvilka, FORBES, 1848, British Naked-eyed Medusie, p. 61. Boiigtiinnllm, AC.ASSIZ, L., 1862, Cont. Nat. Hist. I'. S., vol. 4, p. 344.- Lizusa (young medusa), HAECKEL, 1879, Syst. der Medusen, p. 80. llippocrene, HAECKEL, 1879, Syst. der Medusen, p. 90. Z, A., .^, North Amer. Acal., p. 152. ppocrene, AECKEL, 179, ys. er eusen, p. 90. BougainviUiaj HARTLAI;B, 1897, Wissen. Meeresuntersuch. auf Helgoland, Heft i, Abt. 2, p. 455. Bougainmllea, MAAS, 1905, Ciaspedoten Medusen der Siboga Expedition, Monog. 10, p. 10. neu i, not. 2, pp. 472, 473. Boueainviffia, HART-IIT, 1904, Bull. U. S. Bureau of Fisheries, vol. 24, p. 37. Boii^ainrillfti, GI.RD, 1892, Zool. An/eiger, Bd. 15, p. 312, 5 fign. (cell-division] development of morulu). GENERIC CHARACTERS. Margelina; with 4 radially placed clusters of marginal tentacles, the tentacles ot each cluster being all of one kind and similar in structure each to each. Hydroid: Bougain- There are 4 radially placed, dichoto- mously branching, oral tentacles, a quadratic manubrium, 4 radial-canals, and gonads mi the interradial or adradial sides ot the stom- ach as in other Bougamvillidi. The type species ot the genus is Bougain- villia nmclwiiiHii Lesson, 1836, from the Falk- land Islands. This medusa was first described and figured by Lesson, in 1830, under the nzmtCyaneabougainvilhi. 1 he generic name " (1\iim-n" was, however, previously used by Peron and Lesueur, i8og, for Discomedusa;. \lso the name Hippocrene of Brandt (Mer- tens), 1835, was preoccupied in iSl/byOken for Mollusca and can not be applied to Medusa.-. It therefore becomes necessary to adopt the generic name Bougainvillia. fit;. 84.— Bougainvillia "museui," after Allman, in R.iv Sin-iety, 1871-1872. lflfl MEDUS.E OF THE WORLD. The name "Margelis" was first proposed by Steenstrup, 1850, and applied to designate Margrlis principis of the North Sea, and this name was adopted hy Agassiz and Haeckel. They would designate "Margelis" as being similar to Bougainvillia, but with a manubrium having a narrow base devoid of a peduncle and with the 4 radial-canals opening close together into the 4 corners of the narrow stomach. Bougainvillia, on the other hand, they would restrict to designate medusae with a wide quadratic stomach and often with a peduncle, the 4 radial-canals arising far apart from the 4 corners of the wide cruciform stomach. While these distinctions serve admirably to distinguish "Margelis" principis or "M." carolinensis from Bougainvillia superciliaris, they fail completely to classify medusae in which the manu- brium is of moderate width, neither wide nor narrow. It is my object to retain only positive. Fir,. 85. — Bougainvillia "/r»//Yo'/j," after Allman, in Ray Society, 1871-72. not relative, characters as of generic value. It is futile and confusing to attempt to separate genera upon such intergrading differences as "wide or narrow stomach," "long or short manu- brium," etc., for we generally find that species will be discovered allied evidently to both these so-called "genera," but strictly intermediate in essential characters, Bong/iinvillia takes precedence over Mar gel is and should therefore supplant it. Forbes, 1848, introduced the spelling Bougainvillea, but Lesson's original proposition is Bougainvillia. Haeckel, 1879, p. 90, confuses the hydroid of Bougainvillia with EuJenJrium, but in Eudendnum no free medusx are produced and there are other distinctions separating it from Bougainvillia. ANTHOMEDUSjE — BOUGAINV1LLJA. 157 Nemopsis is separated from Bougainvillia by the tentacles, composing its 4 radially situated, marginal clusters, being of two distinct kinds (clubbed and simple-ended). The mar- ginal tentacles ot Bougainvillia are all of one sort and do not terminate in knobs. Vanhoffen, 1891, shows that we can not separate Nemopsis from Bougainvillia upon the mere length of the radial pouches of its stomach, for some medusx of Bougainvillia display pouches of consider- able length. Tabular Synopsis uj the Medusa of Bougainvillia. B. macloviana Lesson. B.principis= Margelis principis Steenstrup. B. fulva Agassizand Mayer. B. britannica Forbes. B. Miprrciliaris L.Agassiz. B. dim-ma Greene = B. super- ciliaris ( r)* B.multicilia = Lizusa multicilia Haeckel.f Shape and size Cylindrical, Nearly spheri- Cylindrical, High, dome- Dome-like, with Dome-like, 0.75 spherical. of bell in with round- cal. 7 wide, with flatly like. Thick- bulging with bulging 6 high, 5 mm. ed top. i 5 6 high. rounded walled. sides. 10 sides. 12 wide. high, 1 3 top. 14 high, 10 high, 8 Thin uni- wide. high, i i wide . wide. form bell- wide. walls. Number of 35 to 65 in 25 to 30 in sin- I5to2oin sin- 1 6 to 20. Very 10 to 15. 10 to 12 ( ?) to to 12 tentacles double row. gle row. gle row. short, in ~\2 in the ( >nlv 2 per- upon each single row. variety fect tenta- of the 4 mar- B. aun-j. cles seen. ginal bulbs. Shape of mar- V-shaped. Long, linear; Epaulet- Epaulet- Elongate, oval Kidnev- Kidney- ginal bulbs. wider than shaped. shaped. basal bulbs, shaped. shaped. spaces be- of small size. tween them. Shape and Small, cubical. Short, wide. Wide. Half 4-sided, \\ tile, Wide, 4-sided, Small, balloon- Globular to size of man- On broad, 4- sided . as long as urn-shaped. and flask- shaped, flask-shaped ubrium. conical Only one- depth of No pedun- shaped. 4-sided, with con- peduncle. third as long bell-cavity. cle. Only Mounted on hardly one- stricted as depth of No pedun- about half peduncle i .5 fourth as base. \-> bell-cavity. cle. as long as to two-thirds long as bell- peduncle. depth of as long as height. bell-cavity. depth of bell- cavity. Number of 6 to 7 times. 4to5times. 8 times. 6 to 7 times. About ^ times. 4 to 5 times. Simple, un- dichotomous 7 times in branched. branchings the variety of each of B. aurea- the 4 oral tentacles. Character of 4 wide, folded, 4 spherical, 8 adradial. 8 adradial. 4 interradial. 4 interradial. 8 adradial. gonads. interradial interradial. No planulac Planulae swellings. remain develop in attached to capsules stomach. upon siil'"."!" stomach. Color. Stomach and ? Stomach and Stomach and Stomach and StMMi.n h and Stomach light- tentacle- tentacle- tentacle- tentacle- tentacle- vello-A . bulbs yel- bulbs bulbs bulbs rosin- bulbs yel- Tentacle- low. Gon- orange, v--l- golden-yel- yellow to low. Ocelli bulbs ads and low, brown- low. <>ceiii reddish- black. orango ocelli ish-yellow. black. brown. * >(. el- vell'iw. brownish- Ocelli li black. OcelH dark- black. bUK. red. Where found. Falkland North Sea, Tropical North Atlantic Arm* ( kean, East oust nf Sir. nts of Islands, coast of Pacific, coasts of northern Ireland. Gibraltar. South At- Scotland. Fiji to Europe and coasts of lantic. Malay America. Europe and Archipelago. America. Hydruid. Unknown. Unknown. Unknown. Hvdroid has B. gtiperciliaris! been com- monly * . til- ed B." ra- mosa." *This medusa appears to be B. supfreiliaris which has lost some trnt.ulrs. H. r,i, I.inko, 1^04, is pmbablv a \.irii-iv <-\ B. Mtpcrciliarh from Arctic Ocean. fAn immature medusa? l.-.s MEUUS.K OF THK WOULD. The definitions of Bougainvillia and Nemopsis here proposed are identical with those of Hargitt, 1904, p. 37. Species of Bougainvillia are widely distributed in all seas, but are especially abundant in the cold waters of the northern hemisphere, a remarkably large number being found in the North Sea near Helgoland, by Hartlaub, 1897. Many of the species are very closely related and their distinctions may be due in part to environmental influences. Hallez found that "T ulndar Synopsis of the Medusa nj Bougainvillia. — Continued. H.pl.itygaster Haeckel. B. xantha Hartlaub.* B. carolinen- sis= Hip- pocrene carolinensis McCrady. B. niobe Mayer. B.pyramidata = Hippo- crene pyra- midata Forbes. B. nordgadrdi = Margelis nordgaardii Browne . B. flavid.i Hartlaub. Shape and size Cubical. Dome-like, Dome-like. Cylindrical, Semi-globular. Oval. 4 high, Oval. 3 wide, of bell in 12 high, 12 walls very Very thick with flatly- 6 high, 6 wide 4 wide. 2 high. mm. wide. thick. 6 walls. 4 rounded Walls thick. Walls only Walls thick. high, 5 wide high, 4 wide apex. 6.75 fairly thick. high, 4.8 wide. Bell- walls thick. Number of 10 to 12 9 to to 7 to 9 very 8 6 to 8 5 toy. No Not more than tentacles long and ocelli. 6. upon each slender. uf the 4 mar- ginal bulbs. Shape of mar- Triangular, Small, oval to Small, thick, Small, oval. Small, globular. Small, globu- Swollen, fairly ginal bulbs. wider than globular. bulbous. lar. large, bul- spaces be- bous. tween them. Shape and size Flat, 4-sided. Spindle-shap- Narrow, Flask-shaped. Flat, cruciform, Half aslong as Small, conical of manu- No pedun- ed. No ped- widest near Cruciform mounted depth of about h.ilf brium. cle. uncle. mouth. in cross- upon pedun- ' bell-cavity. as long as Half as long section . cle. depth of as depth of Half as long bell-cavity. bell-cavity. as depth of No pedun- bell-cavity. cle. Number of di- 3 or 4 time&. About 2 or 3 2 times. 4 times. 2 times. 4 or 5 times. 3 times. chotomous times. branchings of each of the 4 oral tentacles. Character of 4 interradial. 4 interradial. 4 interradial. Medusa-buds GonaQE itn base 4 interradial. 4 interradial. gonads. arise from 8 and lobes of adradial stomach. sides of stomach. Color. Stomach and Stomach and Variable, us- Stomach and Stomach and Gonads and Stomach and tentacle- tentacle- ually stom- tentacle- tentacle- tentacle- tentacle- bulbs red- bulbs gold- ach and bulbs rosin- bulbs orange bulbs yel- bulbs dish-yellow. en-yellow, tentacle- yellow. to yellow to lowish- orange-yel- Ocelli ? reddish-yel- bulbs green reddish- brown (in low. Ocelli low. Ocelli or green and brown. formalin). black. small, red. Ocelli No ocelli. brownish- black. violet. Where found. Eastern parts Helgoland, Atlantic coast Bali am a West coast of Near Bergen, Helgoland, of tropical German of United Islands, Scotland, Norway- German Atlantic. Ocean. States, tropical south of Ocean, Cape Vrnlr, Woods Atlantic. Ireland. August to Canary Hole to September. Islands. Tortugas. Hydroid. Unknown. Unknown. Hydroid: B. Unknown. Unknown. Unknown. Hydroid: B. carolinensi.s. ffavida Hartlaub. *Medusa allied to B. fariJa AXTHiiMKDI s.K inn c \L\V1I.I.IA. 159 B. frutic'jsa Allman is a form of B. ramosa Van Bencden, which grows in agitated water. The ohservations of GraefFe, 1884 (Arbeit. Zool. Inst. Wien., Bel. 5, p. 34()), are interesting in the same connection, for he found that five distinct forms ot Bougainvillia medusx arise from a hydroid apparently identical with Bougainvillia muscus Allman. It is therefore prohahle that many of our so-called "species" of Bou«nim'illia are merely environmental races. The hydroids of most of them remain unknown, or are not associated with any known medusa, and many of the species are imperfectly described. The following descriptions must he con- sidered as only tentative attempts to unravel the confusion which prevails at present and which can not be dissipated until the hydroids of all or most of the species are discm 1 1< d. Haeckel's 1879, genus " LizHsii" appears to apply only to immature specimens of lion- gainvillia in which the oral tentacles have not \ et become branched. Tabuliir Synopsis nj the Medusa ») Bougainvillia.* — Continued. B.autumnalis Hartlaub = B. gibbsi Mayer. B. prolifera — Luusa prolif- era von Len- denfcld. B. maniculata Haeckel. B. rut;o ,i Clark.-. B. trinema = M jrgelis tri- ne ma von Lcndenfeld. B. fnmdosa Mayer. .Shape and size Dome-like. Dome-like. Nrjrlv spherical. Pyriform. Oval. Dome-like with of bell in mm. £.5 high, 2 3 high, 2. 5 i.i; high, 1-5 1-5 high. 3 widr. vertical sides. wide. wide. wide. 2 high, i .2^ Thick walls. Thin walls. wide. \\..ll thick. Number of ten- 3 to 6 5 4 short, finger- 3 3 2. No ocelli. tacles upon shaped. each of the 4 marginal bulbs. Shape of mar- Rounded, bul- K.ugc, " scrota- Small, globular. Small, globular. Small. Small, w ithout ginal bulbs. bous,fairlv shaped." ocelli. large. Shape and size Short urn-shap- Small, nearly Flask-shaped. Short, thick, Small. Cruciform, short. of manubnum. ed, wide, 4- cubical. Narrow base, flask-shaped. thick, flabk- sided. Not spherical shaped. Half half as long as stomach. as long as depth depth of bell- Long, conical of beil-cavitv . cavity. No throat. peduncle. Number of di- 2 or 3 times. Simple un- Twice. Onlv Unbranched, Kai.li end* m ; 2 or 3 times. chotomous branched. tips branched. simple. branch'-:-. branchings of each of the 4 oral tentacle^. Character of 4 interradial. Medusa-buds on 4 interradial. Not developed ? Not developed 8 adradial. Plan- gonads. sides of stom- (immature). ula- develop ach. upon M !•• of stomach. Color. Slum, H li grren- Stomach .tii'l Stomach and Stomach and Stomach and Stomach an.! it n- brown. Ten- tentacle-bulb:- tnii. 11 lr-bulbs tentacle-bulbs tentacle-bulbs tacle-bulbs tacle-bulbs brown. violet-gray. vrllow, brown. dark-vrlln\\ . pinkish-white. yellowish- Tentacle-tips greenish -yel- turquoise. low. Ocelli black. Where found. Newport, United Port Jackson, Mediterranean. Virginia in s, ,nth Port Jat k ' 11, Tortugas>. States. Helgo- New South Carolina, New South land, (lerman Wales March Atlantic coast U'aK-s, Aus- Ocean. Aug- to April. of United tralia. ust to No\ em- States. • ' ber, and off British coasts. Hydroid. Hydroid un- An imm.iturr 1'nknown. (hdnud: I* \ iiknown. Unknown. known. form ? Un- rugosa Clarke known. *For B. obscitru B»iini-vir and B. ghnella Torrry, see tclt. 160 MEDUS.E OF THE WORLD. There is considerable variability in coloration among individuals of the same species in many forms of Bougainvillia. The preceding tables present a synopsis of the so-called "species," although it is probable that some of the small medusa listed near the end are only the young of those described higher up on the table. Gerd, 1892, finds that the segmentation in the egg of Bouganivillin is at first total and equal and a central segmentation cavity is formed. Then the cells divide tangentially and the nuclei take up a peripheral position. Later there is multipolar ingression into the segmen- tation cavity and thus a solid morula is formed, having all cells similar each to each. The peripheral layer of cells forms the ectoderm of the planula larva. Before the formation of the ectoderm the cell boundaries become indistinct as in Turntopsis, but later they reestablish themselves. Bougainvillia macloviana Lesson. Cyanea bougainvillii, LESSON, 1830, Voyage dc la Coquille, Zoo]., tome 2, part 2, 2d div., Zoophytes, p. 118, plate 14, figs. 3, D-D'". Bougainvillea macloritina, LESSON, 1843, Hist. Zooph. Acal., p. 290. — AGASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 344. Hippocrene macloviana, HAECKEL, 1879, Syst. der Medusen, p. 90, taf. 5, fign. I, 2. — BROWNE, 1902, Annals and Mag. Nat. Hist., ser. 7, vol. 9, p. 278. — BEDOT, 1905, Revue Suisse de Zool., tome 13, p. 135 (literature 1830-50). Adult medusa. — Umbrella a little higher than broad, about 15 mm. high, with a quad- rangular margin, and with longitudinal furrows on the exumbrella. There are 4 V-shaped, radially situated tentacle-bulbs, each giving rise to about 35 to 65 tentacles arranged in a double row. There is a single ocellus at the base of every tentacle. The stomach is small, cubi- cal, and situated upon a broad, cone-shaped peduncle. 4 narrow, perradial lobes extend out- ward from the stomach along the whole length of the peduncle. The mouth is small, with 4 short, perradial lips placed at a point about two-thirds down the depth of the umbrella-cavity. There are 4 closely and thickly branched tentacles, each with 80 to 100 terminal branches ending in knob-like clusters of nematocysts. The gonads are developed upon the interradial sides of the stomach and extend over the sides of the perradial lobes of the stomach, hang- ing down in a folded band from the peduncle. The stomach and tentacle-bulbs are yellow, while the gonads and ocelli are brownish to black. This species is abundant at the Falkland Islands. Mature specimens were recently obtained by Vallentin between November and February at Stanley Harbor and described by Browne. Haeckel's specimens appear to have been immature. Bougainvillia principis. Margelis principis, STEENSTRTP, 1850, Vidensk. Meddel. Nat. For. Kjobenhavn, p. 35. Bougainvillea fruticosa+ B. dllmani, ROMANES, 1876-77, Journal Linnean Soc. London, Zoo!., vols. 12, 13, pp. 526, 190. Margelis principis, HAECKEL, 1879, Syst. der Medusen, p. 88, taf. 6, fign. 14-16. — BROWNE, 1895, Proc. and Trans. Liverpool Biol. Soc., vol. 9, p. 266. Bell nearly spherical, 6 to 7 mm. wide, 5.6 mm. high. Bell-walls only moderately thick and quite uniform. 4 marginal clusters of tentacles. Each cluster arises from an epaulet- shaped base, and contains 25 to 30 short tentacles, shorter than the bell-radius. There is an ectodermal ocellus on the velar side of each tentacle near its base. The basal epaulets of the tentacles are somewhat wider than the interradial parts of the margin between them. The stomach is short, swollen, and without a peduncle. It is not half as long as the depth of the bell-cavity, and its interradial sides are occupied by 4 swollen gonads. The 4 oral tentacles each branch dichotomously 4 to 5 times, thus giving 20 to 30 knob-shaped, terminal branches in each quadrant. Color ( ?) Found off the eastern coast of Scotland and in the North Sea, at Far-Oer Island. The hydroid is unknown. This medusa is distinguished by its short stomach and the remarkable length of its mar- ginal tentacle-epaulets, which are linear, not triangular, in outline. Bougainvillia fulva Agassiz and Mayer. Bougainvillea fulva, AGASSIZ, A., and MAYER, 1899, Bull. Mus. Comp. Zool. at Harvard College, vol. 32, p. 162, plate 2, fig. (>; Ibid., 1902, Mem. Mus. Comp. Zool. at Harvard Coll., vol. z6, p. 145, plate 2, fig. 8. — MAAS, 1905, Craspedoten M-Musen der Sibog/i Exped., Monog. 10, p. 10, taf. I, fig. 8; taf. 2, fign. 9, 10: 1906, Revue Suisse de Zool., tomr 14, p. Sy, plate 2, figs. 4, 5. — BIGELOW, H. B., 1909, Mrm. Mus. Comp. Zool. at Harvard College, vol. 37, p. 195, plates 6 and 44. PLATE 17. Fig. I. Bou%ainvillia supt-rciliaris. Showing planulae developing upon the interradial sides of the manubrium. Woods Hole, Massachu- setts. Fig. 2. Bougainvillia nigosa, young medusa. Charleston Harbor, South Carolina, December 17, 1904. Fig. 3. Bougainvillia tuitiiinnalis, young medusa. Agassiz Laboratory, Newport, Rhode Island, July, 1902. Fig. 4. Bougainvillia autumnalis, mature female. Agassiz Laboratory, Newport, Rhode Island, August, 1892. Fig. 5. Nemopsis bachei. One of the median marginal tentacles of the medusa shown in figure 6. Fig. 6. 'Nemopsis baflici, mature male. Hampton Roads, Virginia, November I, 1904. Fig. 7. Bougainvillia carolinensis, mature male. Charleston Harbor, South Carolina, September 10, 1897. Fig. 8. Bougainvillia britannica, mature female. Eastport, Maine, Sep- tember 19, 1898. Drawn from life, by the author. PLATE 17 . ANTHOMEDU8.fi— BOUGAINVILLIA. 161 The mature medusa is described by Maas, Dr. Agassiz and his assistant ha\ ing found only immature specimens. Mature tni'Jusa. — Bell 8 to 14 mm. high, with thick, vertical sides and flatly rounded top, 4 radially placed clusters of marginal tentacles with about 15 to 20 tentacles in each cluster. These tentacles are not half as long as the bell-height and are clavate and flexible. There is an ocellus on the velar (inner) side of the base of each tentacle. There are 4 straight radial- canals which widen as they join the 4 corners of the stomach. The manubrium is wide at its base and lacks a peduncle. It is about half as long as the bell-height. The 4 oral tentacles branch dichotomously 8 times, and their tips end in knob-like expansions, armed with bristling nematocysts. There are thus 256 tips to the oral tentacles in each quadrant. There are 8 gonads, 2 upon each interradial side of the stomach. These <;onads are dis- tinctly separated in the 4 principal radii. The entoderm of the stomach and tentacle-bulbs is orange-yellow or yellowish-green to brownish-yellow. The gonads are dark-yellow to brown. This medusa is abundant over the western parts of the tropical Pacific, Fiji, Kllicc Islands. Malay Archipelago West Coast of Mexico, Acapulco Harbor. Bougainvillia britannica Forbes. Plate 17, fig. 8. lltppvcrtne britannica, FORBKS, 1X41, Annals ami Mag. Nat. Hist., vol. 7, p. 84, plate i. fit;, i. Bougainvillea britannica, FoRRts, 184X1 British Naked-eveti Medus.T. p. (12, pl.tte 12. fig. I. Euilfndrium ramosum, VAN BENEDEN, 1844, Mem. Acad. Belgu|ue, tome 17, p. 56, planclir 4; iSdo, F;mn.i I.ittor. Belgique, p. 112, plates 6, 7. Bougainvillea ramosa, ALLMAN, 1871, Monog. Tub. Hvdr., p. 311, plate 9, figs. 5-7 (hydroid and medusa). — BOCHU, 1878, Jena. Zeitsch. fur Naturw., Bd. u, p. 189, taf. 6, fig. 6. Margtlis ramosa, HAECKEL, 1879, Syst. der Medusen, p. 88. (?)Ltzusa octocilia (young medusa), HAECKEL, Ibid., p. 80. Bougainvillia ramosa, WEISMANN, 1883, Entstehung Seiualzellen bei Hydromcdusen, (rn.i, pp. 1 13, 218.— BII.I.ARD, 1906, Bull. Mus. Hist. Nat. Paris, No. 5, p. 330. ( ?) Bougainvillia ramosa, PICTET, 1893, Revue Suisse Zoo!., tome I, p. II (hvJnnil Ironi Atnhoin.i, M.il.tv Archipellgo). Lizusa octocilia Dalyell = Bougainvillia ramosa Btihm, HARTI.ACB, 1894, \Visscn. Meercsuntcrsuch. Kciinni. Mern- Kiel, Helgoland, Neue Folge, Bd. r, p. 190. \targelis britannica (Forbes), BROWNE, 1895, Trans. Liverpool Biol. Soc., vol. 9, p. 167. Bougainvillia ramosa, BROWNE, 1898, Journ. Marine Biol. Assoc., N. S., vol. c, p. 187 (hydroid). Margrlis ramosa, BEDOT, 1905, Revue Suisse de Zool., tome 13, p. 138 (citation of papers to 1850). Margclis britannica, BROWNE, 1905, Proc. Roy. Soc. Edinburgh, vol. 25, p. 754. Bougainvillia benedenii, BONNEVIE, 1898, Zeit. fur wissen. Zool., Bd. 63, p. 484, taf. 26. fign. 34. ;<; (degenerating hydroid). (?) Bougainvillia obscura, BONNEVIE, 1898, Bcrgens Museums Aarbog, No. 5, p. 7 (perisarc unringed, 15 tentacles of various lengths). Bougainvillia bella, HARTL.AUB, 1897, Wissen. Meeresuntersuch. Kommis. Mcrr<- Kiel, Helgoland, Ncut* Fnli;r. HJ. 2, p. 470, taf. 15, fig. 7; taf. l6a, figs. 6, 1 1 = B. britannica, Forbes, Hartlaub, 1904, Ibid., B.I. 5, p. 10;. ( .' ?) Bougainvillia muscus, THORNELY, 1900, Zoological Results, A. Willey, Part 4, p. 452 (hydroid from tropical Pacific). Bell about 12 mm. high and 10 mm. wide. High, dome-like, rounded, with very thick walls. Each of the 4 radially placed, marginal tentacle-bulbs gives rise to ifi to 24 short tentacles, about one-fourth as long as the bell-diameter. Each tentacle is provided with a basal ocellus on its inner (velar) side. The ocelli are black in the adult, but mav In red in the young medusa. 4 quite wide radial-canals. Manubrium short and wide without a peduncle. The 4 oral tentacles branch dichotomously 6 to 7 times. There are 8 adradial gonads in the ecto- derm on the sides of the stomach. The ripe eggs are not inclosed in nematocyst capsules Distinctions l>ct •,d n. supcrciltarts. Marginal tenta- cles in each of the 4 radial clusters. Character of stomach. Character of gonads. Color. Length of mar- ginal tentacles in terms of bell-radius (r). B. superciliaris L. Agassiz. 10 to 15 Mounted on short, 4-sided, prismat- ic peduncle. 4 wide interradial. The eggs develop into plan- Ulac nil • nit >t stomach. Rosin-yellow to reddish-brown. 1-5 to 2 r B. britannica Forbes. id tci 24 Nn peilunclr. 8 narrow .i,!r.idu! . V planula- on sides of stomach. Golden-yellow. o.S' MKDCS.K OF TIIK WORLD. and do not develop into planulse while still attached to the medusa. The entoderm of the stomach and tentacle-bulbs is golden-yellow. This species is found oft" the North Atlantic coasts of France, Great Britain, and Germany. It was taken by Hartlaub at Helgoland, German Ocean, in June, and by Browne in the Firth of Clyde, Scotland, in June and July. I found a single mature specimen in the harbor of Eastport, Maine, on September 19, 1898. It appears, therefore, to be widely distributed over the North Atlantic. Pictet, 1 893, states that he identifies the hydroid ol this form from Amboina, Malay Archipelago. The hydroid of B. hrittninicn has been commonly called B. ramosum, and has been well described by Van Beneden and Allman. The stems are much branched and are 25 to 75 mm. high; the ultimate branches are for the most part alternate. The hydrorhiza is branched and root-like, the branches not anastomosing. The perisarc of the stems exhibits shallow annu- lations at the origin of the branches. The perisarc extends in a cup-like form over the sides of the hydranths almost to the bases of the tentacles, so that the hydranth may be almost completely withdrawn into the hollow of the cup. There are about 12 tentacles which are filiform and not very long and arise in a single zone at the base of the conical hypostome. The tentacles are carried nearly straight, with every alter- nate one elevated and depressed. The medusa-buds are borne singly on moderately long pedicels which arise from the bases of the hydranths upon the terminal branches of the stems. There are I to 2 medusa-buds at the base of each hydranth. When set free the medusa has a bell higher than a hemisphere, with fairly thick walls. There are 8 marginal tentacles, 2 in each radial cluster, and 4 short-knobbed, oral tentacles. Browne, 1898, had a hydroid of this species from the Eddy- stone, English Channel, which liberated 4,450 medusa; in 3 days. Wiesman, 1883, finds that the germ-cells of both sexes originate in the ectoderm of the manubrium of the budding medusa and they do not wander from their place of origin, hut remain there and become mature in the free-swimming medusa. Bougainvillia superciliaris L. Agassiz. Plate 17, fig. I. Hippocrene bougainvillii, Goi'LD, 1841, Report on Invertebrates of Massachusetts, p. 348. Hippocrene superciliaris, AGASSIZ, L., 1849, Mem. Amer. Acad., New Series, vol. 4, p. 250, plates 1-3, 53 figs.— STIMPSON, 1853, Maine Invert. Grand Manan, p. II. Bougainvillia superciliaris, AGASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, pp. 289, 291, figs. 37-39; p. 344, plate 27, figs. 1-7. — AGASSIZ, A., 1862, Proc. Boston Soc. Nat. Hist., vol. 9, p. 97, figs. 24, 25; 1865, North Amer. Acal., p. 153, figs. 232-240. — VERRIU., 1873, Report Commiss. Fish and Fisheries U. S., for 1871-72, pp. 328, 733, plate 37, fig. 276. Hippocrene superciliaris, HAECKEL, 1879, Syst. der Medusen, p. 92. Bougainvillea superciliaris, WAGNER, 1885, Wirbellosen des Weissen Meeres, p. 73, taf. 2, fign. 5, 8, 9; nan 6, 7.— LEVINSEN, 1893, Vid. Meddel.Nat. For. Kjobenhavn, ser. 5, Bd-4, p. 144.— MAAS, 1893, Ergeb. der Plankton Exped., Bd. 2, K. c., p. 69. — HARTLAI B, 1897, Wissen. Meeresuntersuch. auf Helgoland, Heft. I, Abt. 2, p. 466, taf. xvia, fign. I, 5, 7-9, 12; taf. xvii, fig. 3; taf. xvir, fign. 3, 4, 11-13; ta^- xv' nR- '• Hippocrene superciliaris, SCHLATER, 1891, Revue des Sci. Naturelles, St. Petersbourg, tome 2, p. 342. — BIRULA, 1896, Annuairc du Mus. Zool. de 1'Acad. Imperiale des Sci., St. Petersbourg, tome I, No. 4, pp. 330, 339. — GRONBERG, 1898, Zoolog. Jahrb., Abth. Syst., Bd. ii, p. 462, taf. 27, fign. 5, 6. Hippocrene superciliaris-^ H. aurea, LINKO, 1904,200!. Anzeiger, Bd. 28, p. 216; 1900, Mem. Acad. Sci. St. Petersbourg, ser. 8, tome 10, No. 3, p. 6, taf. I, fign. 13-18, taf. z, fign. 19-21 (histology of the ocelli). Bougainvillia superciliaris, HARGITT, 1904, Bull. U. S. Bureau of Fisheries, vol. 24, p. 40, I fig. Bougainvillia superciliaris, NETTING, 1901, Bull. U. S. Fish Commission, vol. 19, pp. 330, 376, fig. 90. Bougainvillea paradoxica, MF.RESCHKOWSKV, 1879, Annals and Mag. Nat. Hist., ser. 5, vol. 3, p. 177, plate 20. (?) Hippocrene bougainvillii, BRANDT, 1834, Recueil Actes seances publiques Acad. Imp. Sci. St. Petersbourg, p. 29 (of the "separate"); 1853, Mem. Acad. Imp. Sci. St. Petersbourg, ser. 6, vol. 4, part 2, p. 393, plate 20= Bougainvillea merunsii, L. Agassiz, 1862. Adult medusa. — Bell about 10 mm. in height and about same in diameter. Gelatinous substance very thick, so that bell-cavity is only about half as deep as the bell-height. There are 4 clusters of marginal tentacles which are situated at the bases of the 4 radial-canals. FIG. 86. — Hydroid of Bougainvillia britannica, after Allman, in Ray Society, 1871-72. ANTHOMKDrs.K Hul ( ;\I NVI I.I.I A . Each cluster of tentacles arises from a large bulbous swelling upon the bell-margin. There are 10 to 15 tentacles in each cluster. The tentacles are highh contractile and are normally about two-thirds as long as the bell-diameter. There is a single, very dark-brown ocellus within the ectoderm ot the inner (velar) side of the base of each tentacle. The velum is well developed. There are 4 straight, narrow radial-canals, which arise from the 4 radial corners of the stomach. The stomach is wide and quadratic in cross-section and flask-shaped in longitudinal outline. It is mounted upon a 4-sided peduncle which is about half as long as the stomach itselt. There are 4 radially situated, oral tentacles, each of which branches dichot- omously about 5 times. 1 he mouth is situated at the extremity of a short, simple tube and the lips are not prominent. The mature genital products are situated within the ectoderm of the 4 interradial sides of the stomach. There are thus 4 intei radial gonads, above the zone of the oral tentacles. Ibis species is thus separated from It. li,ll,i by having 4 interradial instead ot 8 adradial gonads. In the temale, according to Hartlaub, l8i;~, the large eggs may be seen lying within the ectoderm close to the supporting lamella. As thev gmw larger they approach the surface, and finally become inclosed in epithelial, nematocyst-bearing capsules, derived from the ectoderm cells of the stomach-wall. These capsules finally protrude from the sides ot the manubrium, but each one remains attached to it by a narrow stalk. In this situation the egg develops into a planula which finally breaks through the walls ot the capsule and escapes into the water. Hartlaub showed that although the large eggs were found in the ectoderm they were derived from the entoderm of the young medusa. In the young and immature medusa the supporting lamella does not completely separate the ectoderm from the entoderm, and the egg-cells then migrate from the entoderm into the DO o ectoderm (see Hartlaub, 180,-, pp. 400, 4-01.* The sperm originates in the ectoderm and there develops without migration. The entoderm of the manubrium and tentacle- bulbs is rosin-yellow or reddish-brown, and tin- gelatinous substance of the bell often has a decided yellowish tinge. HyJirinl mi,/ \riung medusa. — 'I he hydroid is usually found attached to rocks, and lives in the purest sea-water. It grows in clusters, not more than 50 mm. high. The stems give rise to pnmaiy and secondary branches, which arise somewhat irregu- larly, though more or less alternately and spirally. The base ot every branch is ringed with from 510 10 annotations. The chitinous sheath which incloses the stem thins out as it passes on to the polypites and disappears entirely below the circlet of tentacles. Each polypite has from I 5 to 20 long, slender tentacles which arise from a single circlet near the distal end ot the polypite. Each tentacle is ringed at regular intervals by clusters ot nematocv st-cells. The medusa- buds arise singly and somewhat irregularly from the sides of the stem, near the proximal bases of the polypites. Each medusa-bud is inclosed in a thin capsule toimed from the chitinous ectosarc of the stem. When set tree the young medusa usually has X marginal tentacles, 2 at the base of each radial tube. The young tentacles are each provided with a centripetal, ectodermal ocellus. The manubrium is short and tubular and tlu-ie are 4 short, knob-shaped, unbranched, oral tentacles. In common with other Arctic medusa? this species appears upon the southern coast of New England early in April and soon disappears. It is found throughout the summer, however, north of Cape Cod, and mature individuals are occasionally taken at Eastport, Maine, in August. This species has been found by Eevinsen, 181;^. off the west coast of Greenland, and according to Birula, i8g6, it is the most abundant medusa in the White Sea in July. Hartlaub, 1807, found it at Helgoland, and I.inko, 10.04, found it in Barents Sea, * It is interesting to observe that other species of the Bougainvillidi, such as ('\i.ri , .I|*M rrt.iin the emhrvos within the ectin- ilerm of the manubrium until the planula »tji;r. Tins was first observe, I bv Mrr.-si hmvskv, iX?.j, an, I has since been con- firmed by N. Wagner, 18X5, ami by Hartlaub, 1897. Fit;. 87. — Bougainvillia su6ffrc///, Agassiz in Mt'in. Amer. Acad. Arts ami Sci., 1849. Oral view of medusa. Bougainvillia dinema = B. superciliaris (?). Bougainvillea litnema, GREENE, 1857, Nat. Hist. Review, vol. 4, p. 246, plate 15, fig. 6. Margflh zygonema, HAF.IKEL, 1880, Syst. tier Medusen, p. 635. I believe this medusa to be identical with B. superciliaris. (See tabular synopsis.) Bell oval with a constricted margin, 10 to 12 mm. high, 6 to 8 mm. wide. The 4 marginal tentacle-bulbs are kidney-shaped and only half as wide as the intervals between them. Each bulb bears 10 to 12 ocelli. Only 2 tentacles were observed by Greene and Haeckel on each bulb, but the others had probably been broken off. The 2 were at the ends of the bulb. The stomach is roundish, 4-sided, smaller than the tentacle-bulbs, and hardly one-fourth as long as the bell-height. The 4 oral tentacles branch dichotomously 4 or 5 times. The gonads are 4 interradial, triangular to egg-shaped swellings on the sides of the stomach. Stomach, gonads, and tentacle-bulbs yellow. East coast of Ireland. Bougainvillia multicilia. Lizusa multicilia, HAECKF.L, 1879, Syst. der Medusen, p. 81, taf. 6, fig. 13. Bell three-fourths spherical, with thin, uniform walls, evenly rounded, fi mm. high, 5 mm. wide. 4 wide, kidney-shaped, marginal tentacle-bulbs, wider than the intervals between them; each with 10 to 12 tentacles with ocelli, and about as long as the bell-radius. 4 straight. ANTHOMKIHS.K l« H'CAINVI I.I.I A. I CM narrow radial-canals. The velum is narrow. The stomach is globular with a constricted base, but no peduncle. 4 simple, unbranched oral tentacles, each ending in a single nematocyst- knob. 4 pairs ol gonads on the adradial sides of the stomach. Stomach light-yellow. ( jonads and tentacle-bulbs orange-yellow. ( kelli dark-red. Straits of Gibraltar in March. This may be a young form, the shape ot the bell and unbranched condition of the oral tentacles being indications ot immaturity. Bougainvillia platygaster. Hippocrenr plalygasler, HAECKEL, 1879, Syst. tier Mi-ilusen, p. 91. Bell cubical, flat above. 12 mm. high, 12 mm. wide. The 4 radially placed, marginal tentacle clusters arise from wide, triangular, basal swellings, which are wider than the inter- radial spaces between them. Each basal swelling gives rise to 10 to 12 tentacles, which are shorter than the bell-diameter. The tentacles arise in a single row from their basal bulbs. Ocelli ( ?) Stomach flat and 4-sided. It is 4 times as wide as high, and without a peduncle. The 4 short, oral tentacles branch dichotomously 3 or 4 times, giving 8 to 16 short, terminal ramuli in each quadrant. The 4 wide, rectangular gonads are on the interradial sides of the stomach. The stomach, gonads, and tentacle-bulbs are reddish-yellow. Atlantic Ocean, Cape Verde, and Canary Islands. Distinguished by the wide, triangular, basal bulbs of its marginal tentacles, and its short, wide, 4-sided stomach. Bougainvillia xantha Hartlaub. Bougaim'illia \antlia, HARTLAUR, 1X97, Wissen. Meeresuntersuch. Kommis., Meere Kiel, Helgoland, Neue Folge, Bd. 2, p. 461, taf. 15, fign. 2, 3; taf. l(ia, fig. 3; taf. l6i, fig. 19. Young medusa. — Bell rounded, somewhat higher than wide, with thick gelatinous walls. Height 4 or 5 mm. Bell-margin 4-sided. Each of the 4 radially situated, marginal tentacle- bulbs gives rise to 9 or 10 tentacles, with small, indifferently developed, brownish-violet ocelli. 4 quite wide radial-canals. Manubnum small, with 4 branching oral tentacles longer than the manubnum. The oral tentacles branch dichotomously about 4 times and each ends in about 16 nematocyst-knobs. These terminal branches of the oral tentacles are very short in com- parison with the length of the main shaft of the tentacle. The 4 interradial gonads begin to develop in specimens about 4 mm. wide. The tentacle-bulbs and stomach are light golden- yellow to reddish in color. The interradial entodermal lamella is translucent greenish-yellow. Common at Helgoland from March until the end ot June. No mature specimens have been seen and the hydroid is unknown. It is closely allied to K. ftiiviJn and may be only a variety of the latter form. It appears, however, to have more marginal tentacles in corresponding stages of growth than is seen in R. flnviJn and there are slight color differences. Bougainvillia carolinensis Allman. Plate 16, figs. 7 tu 9; plate 17, fig. 7. Hifiporrfne tarolinfnsn, McCfiADV, 1857, Gynin. Charleston Harbor, p. hi, plate 10, figs. 8-10. Margelis carolinrnsis, AI.ASSIZ, I,., 1862, Cont. Nat. Hist. l; . S., vol. 4, p. 544. Anssi/, A., 1865, North Amir. Acal., p. 156, tigs. 241-248.— HAECKEL, 1879, Syst. iler Meilusen, p. 89. Bou^ainl'illia ctirolinensis, AI.LMAN, 1871, Monog. Tubul. Hvdroids, p. 316. Hougiiimi/lia carolinensis, NUTTINC., 1901, Bull. U. S. Fish Commission (or 1X99, vol. 19, pp. 350, 376; figs. 5, 89.- HARCITT, 1904, Bull. I'. S. Bureau of Fisheries, vol. 24, p. 39, plate 2, fig. 4; 1901, American Naturalist, vol. ^, p. ^83, fig. 46. AJult nit'Jnsii (plate 17, fig. "). — Bell dome-shaped and 4 mm. in height. Bell-walls, especially at apex, very thick. There are 4 radially arranged clusters of marginal tentacles that arise from 4 small, bulbous, basal swellings. 7 to g tentacles in each cluster. The longest of these tentacles attain a length about equal to the bell-height. The tentacles are slender and quite stiff, and their tips are usually curled downwards in a semicircle. A large ectoder- mal ocellus is situated at the base of each tentacle upon the ventral (centripetal) side. The velum is well developed. There are 4 straight, narrow, radial tubes. The manubrium is long and narrow, and extends for about half the distance from the inner apex ot the bell- cavity to the velar opening. Near its distal end it is somewhat wider than at its base. The mouth part, however, is a simple, narrow tube. 4 oral tentacles arise from the 4 radial sides MKDrs.E OF THE WORLD. of the mouth-part of the manubrium. Each one of these branches twice dichotomously, thus giving rise to 4 tentacle tips in each quadrant. The gonads are found in the ectoderm of the manubrium, where they occupy longitudinal, interradially situated, swollen regions. In the Tortugas and Charleston Harbor examples of this species, the entoderm of the tentacle-bulbs and of the manubrium is of a delicate sage-green. The gonads are cream- colored, and the tentacular ocelli dark-brown or black. In northern examples of this medusa, found at Newport, Rhode Island, and Naushon, Massachusetts, according to A. Agassiz, the tentacle-bulbs are colored with brilliant red, surrounded by a green edge bordered with bright- yellow, and the digestive cavity is brick-red or green. No such brilliant coloration has been observed by me in southern examples of this species. The hydroid stock has been figured by A. Agassiz, 1865, p. 158. It occurs very commonly upon Fuciis vesifulosus, where it grows in dense clusters. The main stems are often 230 to 270 mm. in length. They taper gradually from base to summit and branch profusely and pin- nately. The side branches do not often give rise to secondary branches. Great numbers ot ringed pedicels, which terminate in polyp-heads, arise from the sides of the main stem and also from the branches. The polypites are fusiform and possess a single circlet of about 15 long, slender tentacles near the distal extremity. The mouth is situated at the apex of a slight, conical proboscis. Medusa-buds make their appearance anywhere all over the stems, where they appear either singly or in clusters. When set tree the young medusa is about 1 .7 mm. in height. The bell is pyriform in outline, and the gelatinous substance quite thick. There are 8 tentacles, 2 at the base of each of the 4 radial tubes. The tentacles are all provided with basal ocelli. The manubrium is small, slender, and tubular, and there are 4 short, unhranched, oral ten- tacles. The general color of the stems of the hydroid is of a horny green and the polypites are often of a delicate rosy tint. This medusa is very abundant throughout the summer in Charleston Harbor, South Car- olina. It is much rarer at the Tortugas, Florida. The brilliantly colored, northern variety is said to be quite common upon the southern coast of New England, but it has never been found north of Cape Cod, Massachusetts. Hargitt, 1901 (Biol. Bulletin, Woods Hole, vol. 2, p. 228), discovered a remarkable twin sport, apparently of this medusa. It had 2 manubria fused at a common base so as to form a common stomach. Each "twin " had a complete bell-margin, only the sides ot their bells being fused one to the other. Bougainvillia niobe Mayer. Plate 18, figs. 1-3. Bougainvillia niohe, MAVF.R, 1894, Bull. Mus. Comp. Zool. at Harvard College, vol. 25, p. 236, plate I , fig. 2: Ifiiil., vol. 37, p. 42 ; 1904, Mern. Nat. Sd. Brooklyn Institute Museum, vol. i, p. 11, plate z, figs. 14-ijr. Adult medusa (plate i8,fig. I ). — Bell 6.75 mm. high and 4.8 mm. in diameter, with vertical sides and thick, gelatinous walls. 4 radially situated clusters ot marginal tentacles, each com- posed of about 8 tentacles about as long as the bell-height. On the velar side of each tentacle, near the bulbous base, there is a dark-colored ocellus. 4 straight, narrow radial-canals. Manubrium wide, flask-shaped, and cruciform in cross-section. About half as long as the height ot the bell-cavity. 4 radially situated clusters of oral tentacles, each of which branches dichotomously 4 times. These are very flexible and their distal ends are knobbed. Medusa-buds arise from the 8 adradii of the manubrium, the youngest buds being im- mediately under and on both sides of the point of entrance of each radial-canal, while older ones are found farther down the sides of the stomach. The young buds are small, ovoid vesicles contained entirely in the ectoderm. The limiting membrane, between the entoderm and ectoderm of the manubrium in the neighborhood of these buds, is entire (plate 18, fig. 3), and I can find no evidence of cells passing through it. Indeed, throughout the future develop- ment of the buds, the entoderm remains inert and its limiting membrane unbroken. The wall of the vesicle consists of 2 layers of cells: an outer epithelium of ectodermal cells, des- tined to give rise to the ectoderm of the hud, and an inner layer of somewhat larger cells destined to give rise to the entoderm of the budding medusa (plate 18, fig. 2). These latter cells are entirely incased by the ectoderm of the parent. They may, however, have been PLATE 18. Fig. I. Bougainvillia niobc, Nassau Harbor, Bahamas, March 18, Fig. 2. Roiiaiilnvillla niobc, section ot a young medusa-bud upon the ecto- derm of the manubrium. r, central mass of degenerating cells; c <• t, ectoderm of the manubrium of the parent medusa; c n t, (brown) entoderm of the parent medusa; e c t b, (gray) ectoderm of the budding medusa; e n t b, (green) entoderm of the budding medusa; s I, limiting membrane between the ectoderm and ento- derm of the manubrium ot the parent medusa. Fig. 5. Bougainvillia niobc. Cross-section of the medusa showing the budding region of the manubrium. Successive stages in develop- ment of buds are shown in hi b4. Colors as in figure 2. Fig. 4. R/it/iki'/i flea/ins, mature male. Tortugas, Florida, July I, 1899. Fig. 5. Rathkea octof>unct[ S.K HnrCIATXVII.i.IA. 1C.7 derived at an earlier stage from the entoderm of the parent medusa and have migrated into the ectoderm. Careful search has, however, failed to reveal evidence of any such migration, and in default of evidence to the contrary, we assume that these cells niiiv he ectoilermal in origin, although destined to produce the entoderm of the hud. The central cavity of the vesicle is partially rilled with a loose mass of nuclei and cell ma- terial showing little or no trace of cell boundaries (r, plate 18, fig. 2). These are present at all stages of the developing hud, partially filling the gastrovascular cavity, hut they appear to degenerate in later stages, and it seems possible they serve to nourish the bud in its urowth. This supposition appears the more probable from the fact that the gastrovascular ca\itv of the bud is never in connection with that of the parent medusa. \Ve have, therefore, a graded series of phenomena in the asexual production of medusa- buds by hyd mined usx. Where the ectoderm and entoderm are both thin-layered and of about equal thickness, such as in Stirs in and F.uclifilr,t,i p,nnj<,\iia, both entoderm and ectoderm take an equal share in the formation of the bud. In forms such as Ruthk,,: 'i.t't[>un<-tntti and •* ' ° '• 1 i I 1 . i m S: -V Ao,," Sq. 89. 9°- l-'n,. Sij. Hvilrohl of Hvitem liearin^ medusa-buds. I']'.. 90. — Boutylim'illiil niuhf, from life, liy the author. Tortuy.is. I;lon.la, June 2", 1908. Lizzin fliiftrirt-tli-i, according to Chun, Bibliotheca Zoologica, 1895, a different condition is observed, for the medusa-buds are formed entirely within the ectoderm of the parent, although the gastiovascular cavity of the bud finally acquires a connection with that of the parent, tin entoderm of the bud becoming continuous with that of the parent manubrium. In Bougainvillia nin/ii-. however, the ectoderm is very thick and the budding medusae are developed within it alone, the entoderm of the parent medusa remaining inert and passive during the growth of the bud, and no connection ever being established between the gastro- vascular cavities of the bud and the parent. This result may he regarded as due to a gradual process favored by the thickness of the ectoderm, which prevented the deep-lying entoderm from taking an equal share in the formation of the bud. until fiuallv it remains passixi- throughout the period of the formation of the bud. Medusa? produced from ectoderm alone may, therefore, be phylogenetically homologous with medusae produced by the more primi- tive and universal cooperation of both ectoderm and entoderm. The entoderm of the manubrium and tentacle-bulbs of K. niobe is rosin-colored, all other parts being transparent. There is a dark-colored ocellus on the velar side of each tentacle near the basal bulb. This medusa is found in Nassau Harbor, Bahamas, in April. 168 MF.TH'S.-E OK THE AVORLD. Bougainvillia pyramidata. Hipforrrur f\ramiilaia, FORBES AND GOODSIR, 1853, Trans. Roy. Soc. Edinburgh, vol. 20, p. 312, plate 10, fie. 4. — HAFCKH , iSSo, Syst. .ICT Mcilusrn, p. 635.— BROWNE, 1905, Proc. Roy. Soc. Edinburgh, vol. 25, p. 75?. Bell semiglobular, 2.5 to 6 mm. wide and equally high. Bell-walls thick and gelatinous substance at apex well developed. The 4 marginal tentacle-bulbs are very small and globular, and each one bears 6 to 8 tentacles which have ocelli and are somewhat shorter than the bell-diameter. The stomach is mounted upon a short, conical peduncle. It is cruciform and its 4 lobes extend along the entire length of the peduncle. The mouth is a circular opening. The 4 oral tentacles branch twice dichotomously. The gonads are upon the basal margin of the stomach and its lobes. The radial-canals are straight and narrow. Stomach, gonads, and tentacle-bulbs orange-yellow to reddish-brown. Tentacular ocelli black. Found off the west coast of Scotland and off the south coast of Ireland. Bougainvillia nordgaardii. Margtlis nordgaarJii, BROWNF, 1905, Bergens Museums Aarbog, No. 4, p. 14, plate 2, fig. I, plate 3, figs. <, 6. Bell 4 mm. wide, 4 mm. high. Bell-walls uniform and of moderate thickness. Bell dome-like, evenly rounded. 5 to J tentacles in each of the 4 radial bulbs. No ocelli. Ten- tacles somewhat longer than the bell-diameter. Velum narrow. Stomach half as long as the depth of the bell-cavity. 4 oral tentacles, 4 or 5 times dichotomously branched. 4 wide, mterradial, gonads on the sides of the stomach. Gonads and tentacle-bulbs yellowish-brown (in formalin). Byfjord, near Bergen, Norway. Distinguished by its lack of ocelli. For details see tabular synopsis of medusae of Bougainvillia. Bougainvillia flavida Hartlaub. Bougainvillia imillin faritla, HARTLAUB, 1897, Wissen. Meeresuntersuch. Koinmis. Deutsch. Meere Kiel, Helgoland, Neue Folge, Bil. i, p. 456, taf. 14, figs, i-io; taf. 15, figs. 4-6, 8. The mature medusa is slightly higher than a hemisphere with an evenly-rounded bell. The gelatinous substance is thick, so that the bell- cavity is only a little more than half as deep as the bell-height. The bell is 2 or 3 mm. wide. There are 4 radially placed clusters of marginal tentacles with not more than 6 tentacles in each cluster. These tentacles are about as long as the bell- diameter and each one has a large ocellus upon its velar side near the base of the cluster. The 4 com- mon, basal bulbs are swollen, semiglobular, and well developed. 4 quite wide, straight radial-canals and a narrow, simple, circular vessel. Manubrium small, conical, half as long as the depth of the bell-cavity. Without a peduncle. The 4 oral tentacles branch dichotomously about 3 times. With mterradial, undivided gonads. Entoderm of manubrium and tentacle-bases orange-yellow. The mature medusae are found at Helgoland, German Ocean, in August and September. Hydroid. — The hydrorhiza is net-like, creeping, and yellowish-brown in color. The stems arise at quite infrequent intervals and are unbranched, very slender below and swollen above at the polypite. They are 5 to 7 mm. high and light gray-brown in color. The hydranths are elongate, club-shaped, with 8 to 10 tentacles in a single zone around the mouth. The medusa-buds are produced upon branching processes which arise from the sides of the stem near the base of the polypite, or from points lower down upon the side of the polypite !i',.' 4. hi; 14, t v HAM. ITT, 1904, Bull. U. S. Bureau of Fisheries, vol. 24, p. 40; 1901, American Naturalist, vol. 35, p. 583. Bell rounded, 2.5 mm. wide, somewhat higher than a hemisphere, with thick, gelatinous walls. 4 bulbous, rounded, marginal tentacle-bulbs, each of which gi\es rise to 3 to , Mem. Huston Soc. Nat. Hist., vol. 3, p. 140, plate 8, figs. 11-14. ) tniti^ ini-1/iisn (plate 17, tig. 2). — Umbrella somewhat pynlorm. 12 marginal tentacles, $ at the base ot each radial tube. Tentacles all of equal size. According to Clarke, ocelli air developed only at the bases ot those 2 tentacles which are first and second as one passes around the bell from left to right, but I found a specimen with 12 ocelli, one at the base nf each tentacle. The velum is well developed. There are 4 straight, narrow, ladial tubes. The manubrium is short and thick, and there are 4 short, unbranched, oial tentacles. H \drnid. — The hydroid stock attains a height of 75 mm. There are numerous irregu- larly arranged branches. Some of the branches which arise near the proximal end arc about as long as the main stem, but most of them are short and delicate. The branches bear secondary branches which give rise to 3 or 4 terminal ramuli. The hydroid is rooted by a creeping stolon. The polypites are fusiform and are protected by an expansion ot the pensarc which bears a number of annulations. There are 8 to 10 short tentacles. The medusa-buds are borne upon the ultimate branches immediately below the proximal bases ot the polypites. I lie hydroid is light-brown. It was found by Clarke, 1882, growing upon .//< \rnildluin at Hampton Roads, Virginia, and in the southern parts of Chesapeake Bay. A medusa believed to be of this species was found by me in Charleston Harbor, South Carolina, on December 17, 1904. Bougainvillia trinema. Margin trinemti, VON LKNDKNFELD, 1884, Proc. Linncan Soc. New South Wales, vol. 9, p. 918, platr 41, fig. i }. An immature medusa from Sydney Harbor, New South Wales, Australia. The bell is oval, rounded, 2 to 3 mm. wide. There are only 3 tentacles in each of the 4 clusters of marginal tentacles. These are about half as long as the bell-height. Each of the 4 oral tentacles ends in 3 ( ?) small, equal branches about one-third as long as the shaft of the oral tentacle. Ento- derm ot stomach and tentacle-bulbs dark yellow. This may possibly be the young of II. fulva Agassiz and Mayer, 1899, but von Lendenfeld's description and figure are too imperfect to determine this point. Bougainvillia frondosa Mayer. Plate 16, fig. 6. Bougainvillia fronJosa, MAYER, 1900, Bull. Mus. Comp. Zool. at Harvard Collide, vol. 37, p. 41, fig. 5, plati- -,. The bell is higher than a hemisphere with relatively straight, vertical sides, and about 2 mm. high. There are 4 radially placed clusters of marginal tentacles, which are situated upon bulbs at the ends of the 4 radial-canals. Each bulb gives rise to but 2 tentacles, so that there are only 8 in all. There are no ocelli at the bases of the tentacles. The velum is narrow. There are 4 straight, narrow radial-canals and a simple, narrow ring-canal. The manubrium is cruciform in cross-section, short, thick, and flask-shaped. It extends about half the dis- tance from the inner apex of the bell-cavity to the velar opening. There are 4 radially placed. oral tentacles, each of which branches dichotomously 2 or 3 times. Planulx develop upon the sides of the stomach near, and on both sides of, the 4 principal jadn. I at first consid- ered these to be parasitic Zooxanthellae, but further studies have shown that they are pl.innl.i Hartlaub, 1897, observes a similar phenomenon in Bougainvillia superciliarii, etc., and Maas, 1904, cites it in (*.\two/m.<, AGASSIZ, L., 1X49, Mem. Anier. Acad., New Series, vol. 4, p. 289; 1862, Cont. Nat. Hist. U. S., vol. 4, p. 34^. — McC-RADY, 1857, Gyrnn. Charleston Harbor, p. 58. — AGASSIZ, A., 1862, Proc. Boston Soc. Nat. Hist., vol. 9, p. 98; 1865, North Amer. Acal., p. 149. — HAF.CKEL, i879,Syst.der Medusen, p. 92.— BROOKS, 1883, Studies Biol. Lab. Johns Hopkins University, vol. 2, p. 468. — HARGITT, 1904, Bull. U. S. Bureau of Fisheries, vol. 24, p. 37. This genus was founded by L. Agassiz, 1849, t°r Nemopsis bachci of the Atlantic coast of the United States south of Cape Cod. GENERIC CHARACTERS. Margelmae with 4 clusters of marginal tentacles, one at the extremity of each of the radial- canals. There are two sorts of tentacles in each cluster, a median pair of club-shaped tentacles with swollen extremities studded with nematocysts; and on both sides of this median pair there are a number of simple, filiform tentacles. The 4 radial lobes of the stomach extend out- ward along the radial-canals and the gonads are developed along the sides of these lobes. The hydroid is a Bougainvillia. In the Nemopsis hydroid, however, the medusae arise from the sides of the naked polypites, not trom the branches of the stems of the hydroid, as is usual in other species of Bougainvillia. In common with Bougainvillia the medusa of Nemopsis has 4 dichotomously branching, oral tentacles. Its most striking feature is the wide extension of the 4 radial pouches of the stomach along the 4 radial-canals. This is, however, not of generic value, for it occurs to a greater or less degree in Bougainvillia. The sole distinctive generic feature of N emopsis is the presence of two distinct sorts of tentacles upon each marginal bulb. L. Agassiz, in his first brief notice of this genus in 1849, called attention to its peculiar club-like median pair of ten- tacles and presents a good figure of them, but his description is not wholly correct, for the ocelli are not upon the ends of the tentacles, but are on the axial (inner) side of each tentacle adjacent to the pad-like base. Haeckel, 1879, considers Nemopsis to be identical with Favonia of Peron and Lesueur, 1809; nevertheless he adopts the name Nemopsis, although maintaining the precedence of Fnvnnin. I agree with VanhSfFen, 1891, and consider that Favonia is certainly not equivalent to Nemopsis. Blainville's (1834, Man. d'Actinologie) copy of Peron and Lesueur's figure of ANTHOMEDU&E— NEMOrSIS. 17.'! Favonia and his briet and unsatisfactory description are only confusing. It is evident that the figure is very erroneous, and it appears to hear a closer relationship to I.\'»ni,-iii-lii-i ot our coast. It was described from an isolated specimen found on the coast of \<>i- way, and falls within the common limits of variability of N. bachci in all respects. It is possibly an individual which may have drifted across the Atlantic in the trend of the winds and currents. The genus Nftnnpsis is evidently derived from the more generali/.ed l}nn!'Min,'in,i among the Tiariiue is another instance ot the same sort. In the medusa; we frequently find that the hard and fast distinctions which Haeckel attempts to apply to the separation of families do not hold in nature. Thus the gonads are often more or less interradial in the Codonidae, or more or less upon the sides of the manubrium in the Thaumantiada;; the lithocyst-bearing medusa l:ntn>i,i arises from a hydroid having the superficial appearance of one of the Tubularian order, and Rntlikca fascicultita is the only medusa of the Oceanidae with 4 frrr/iJinl gonads. Nemopsis bachei L. Agassiz. Plate 17, figs. 5 anil 6. Ncmopsn bachei, AGASSIZ, L., 1849, Mem. Amer. Acad., New Scries, vol. 4, p. 289, i fig. 1862, Cont. Nat. Hist. I . s., vol. 4, p. 345. — AGASSIZ, A., 1862, Proc. Boston -Soc. Nat. Hist., vol. 9, p. 98, figs. 26, 27. — 1865, North Amir. A. ll., p. 14*), figs. 227-231 . — VKRRILL, 1873, Report Commis. Fish and Fisheries U.S. for 1871-72, pp. 454, 733- — HAF< KM, 1879, Syst. der Medusen, p. 93. — BROOKS, 1883, Studies Johns Hopkins Univ. Biol. Lab., vol. 2, p. 468 (hvdrmd and young medusa). — BROOKS, 1890, Handbook of Invert. Zoo]., p. 40, fig. 21. — NI'TTING, 1901, Bull.U. S. Fish Cnmmis- sion for 1899, vol. 19, p. 375, fig. 88. — HARGITT, 1904, Bull. U. S. Bureau of Fisheries, vol. 24, p. 41, I fig.; 1901 , Ameri- can Naturalist, vol. 35, p. 583, fig. 47; 1901, Biol. Bulletin, Woods Hole, vol. 2, p. 227. Vfinnftsi! gibbuii, McCfiADV, 1857, Gymn. Charleston Harbor, p. 58, plate 10, figs. 1-3, non figs. 4-7. Favonia bachei, HAECKF.L, 1877, Prodrom. Syst. Medusen, No. 103 (unpublished). .Vemopsis heirronema, HAF.CKEL, 1879, Syst. der Medusen, p. 93, taf. 5, fign. 6-9 (isolated specimen from coast of Norway). Adult medusa (plate 17, fig. 6). — Bell about II mm. high, being higher than a hemi- sphere, with relatively straight sides and flat top. There are 4 radially situated clusters ot marginal tentacles. Each cluster arises from a cleft, pad-like base and contains about 14 tentacles. The median pair of tentacles are short, slender, and terminate each in a knob- like cluster of nematocysts (plate 17, fig. 5). These median tentacles are flanked by a long, highly contractile pair which contain reddish-brown pigment in their ectoderm. On either side of these brown tentacles there are 5 transparent, highly contractile, filiform tentacles. When swimming the medusa often carries its tentacles with their shafts extending straight outward at an acute angle with the sides of the bell, while the extremity ot each tentacle bends sharply downward at a right angle, recalling the appearance presented by the tentacles ot Gonionemus. There is a dark-colored ectodermal ocellus at the base of each tentacle on the lower (velar) side. The bell-cavity is about three-quarters as deep as the bell-height. There are 4 straight, narrow radial-canals and a slender circular vessel. The velum is well developed. The gonads are flat and ribbon-like, with curtain-like folds, and they extend down the radial- canals, along the sides of the 4 stomach-pouches, which project about two-thirds the distance from the sides of the manubrium to the tentacle-bulbs. The manubrium is short, with 4 simple, quadratic lips, and with 4 radially situated clusters of oral tentacles. Each of these oral clusters arises from a single shaft which bifurcates from 5 to 7 times, terminating in 32 to 128 small, nematocyst-covered knobs. The entodermal cores ot the oral tentacles consist of chordate cells. Gonads, stomach, and tentacle-bulbs dull milky-yellow to orange. This '4 174 .M 101)1 S.K OK THK WORLD. medusa is very abundant in autumn and winter along our Atlantic coast near the mouths of large hays into which pure ocean water has free access. It is not usually found in brackish water far from the ocean. It is found at Woods Hole, Massachusetts, and is common in Long Island Sound as far west as New Haven; in the mouth of the Chesapeake; in Pamlico Sound, especially near the inlets, and in the mouths of all southern harbors, in winter, as far south as Fernandina, Florida. It is also found off the coast in the ocean. It has not been seen north of Cape Cod, nor upon the southern Florida coast. Very often the medusa is seen with all of its marginal tentacles broken off short, leaving only rounded stumps, this condition being commonly found in animals living in brackish water or far from the ocean. N. " hetero- iifnui" HaeckeJ, 1879, appears to be identical with our American TV. b/ichei. HyJronl . 1X7; iX;X, Mom. Acatl.Inip.St.Prirn.bnurjvrr.fi. fine 4.,,.-;-. rv/. 345.— AC;ASSIZ, A., 1865, North Amer. Acal., p. l6l.---\Vv.\t R, ]XS<;, W,rhrl|..M-n .!.-> \V.-i- i-n \|..-r.--. p. 73.— GARSTANI., 1904, Journ. Marine Biol. Association, Plymouth, New Series, vol. -,, p. 213. \U^. iSir. M> m. M'i Conip. Zool. at Harvard College, vol. 23, p. 14.— HARI.ITT, 1904, Bull. tr. S. Bureau "I 1 i li, n, . \..|. -4. p. 37. Rtahlaa+tfargelllam+Laaaa,Cuu«, tXne, Biblmtheta Znnlngica, Hrft 19, l.fg. i, pp. 13, if>, 24, 3/1, tic. Marfrllium, BRUWNE, 1X95, Proc. and Trans. Liverpool Biol. Sot., \ol. ln,-iilin,hii Brandt, of the Black Sea. 1 believe future studies will show that this medusa is identical with Rntlikr/i rjctnpiiiiitntn. In 1846-48 Forbes introduced the generic name " Lizziti," applying it to I.IT.ZHI mtn- piiiictntti, which Browne and Garstang have shown to be identical with ('. \ttm in /o/>j//i, tutu of Sars, 1835. Haeckel, 1879, defines the following genera: Haeckel 's name. Lizzia. Margelhum. Lizzella. Rathkca. Condition of oral tentacles. Condition of the Xclustersof marginal tentacles. Unbranched . 4 radial clusters have more tentacles than the 4 interradial. Branched. 4 radial clusters have more tentacles than the 4 interradial. I'nbranchcd. All X tentacular clusters alike. Branched. All S tentacular clusters alike. Vanhiiffen, 1891, shows that " Lizzia, Margellium, and Ltzzflla" are stages in the growth of Ruthkca. Much confusion has thus been introduced by the too narrow definition of genera, as restricted by Haeckel, and it seems well to broaden the genus so as to make it apply to these medusae in all stages of their free lite. GENERIC CHARACTERS. Margelinae with simple or branched oral tentacles and 8 clusters of marginal tentacles, 4 radial and 4 interradial. There are perradial, adradial, or interradial gonads on the sides of the stomach and the oral tentacles terminate in knob-like clusters of nematocysts. In Rat/ikca medusa-buds are commonly developed upon the sides of the manubiium. Chun, 1895, has shown that these buds are produced entirely from the ectoderm of the parent medusa. A short time before the young medusa is set free, however, a connection is estab- lished between the gastrovascular cavity of the bud and that of the mother medusa. Claparede, 1860, describes a "Lizzia" from Scotland in which the embryos are developed upon the outer walls of the stomach very much as is the case with the planulae ot Brmgantvillia superciliaris. In the case of this "Lizzia," however, the eggs, or embryos, are set free inclosed in capsules and then develop directly into medusae. This remarkable observation awaits confirmation. According to Browne, 1896 (Proc. Zool. Soc. London, p. 477), the medusa of Lizzm ( Rut liken ) nftnpunftata first reproduces itself by means of medusa-buds upon the_manubnum, and when it reaches the adult condition either ova or spermatozoa develop within the ectodermal wall of the stomach, the sexes being separate; and the same statement applies to Rntlik,-) Oceania blumenbachii, RATHKF, 1835. Mem. Acad. Imp. Sci. St. Pe'tersbourg, tome 2, p. 321, 4 figs. Cyttris (?) octopunctala, SARS, 1835, Beskriv og Jagttag, p. 28, plate 6, figs. 14^-14^. Cytais octopunctata, SARS, 1846, Fauna Littor. Noveg., tome I, p. 10, plate 4, figs. 7-ij.--l.iNKO, 1900, Travaux Soc. Imp. des Nat. de St. Pctersbourg, tome 29, p. 152, fig. 2. TT • . . ._»? . - O . » ,Hf_._XT_-U'. I _ .. O . \taryellium octopunctatum+ Rathkea 17S MEDl'S.E OF THE WORLD. Ralhkta oclopunclala, GIARD, 1888, Bull. Sci. France Belg., ser. 3, annee I, p. 317, plate 21.— CHUN, l896,Bronn's Thier-Reichs, Bd. ^, Abth. l, p. 253, taf. 12 (development of medusa-buds).— BEDOT, 1905, Revue Suisse de Zool., tome 13, p. 145 (all papers cited to 1850). \largtllium actopunctalum, BROWNE, 1903, Bergens Museums Aarbog, No. 4, p. 15; 1905, Proc. Royal. Soc. Edinburgh, vol. 25, p. 755. Cubogasler gemmascens, HAECKEL, 1879, Syst. der Medusen, p. 76, taf. 6, figs. 8-[l (young budding medusa with only 2 mar- ginal tentacles). Adult medusa. — Bell pyriform,with solid, apical projection, and about 5 mm. in height and 4.5 mm. in diameter. Gelatinous substance thick at the apex of the bell, but thin upon sides of bell-cavity. There are 8 clusters of marginal tentacles. 4 of these are radial and are situated at the bases of the 4 radial-canals, and the 4 others are interradial and are situated 45° from the radial clusters. In the fully-grown medusa there are usually about 4 or 5 tentacles in each radial cluster, while the interradial clusters are each composed of not more than 3 tentacles. When the medusa is not yet fully grown, however, there are normally 3 tentacles in both radial and interradial clusters. Tentacle-bulbs large and swollen and filled with entodermal pigment- granules. Velum well developed. There are 4 straight, narrow radial-canals. The manu- brium is provided with a distinct peduncle which, however, does not extend more than one- third of the distance from the inner apex of the bell-cavity to the velar opening. The gastric portion of the manubrium is short and quadratic in cross-section. The mouth is surrounded by 4 prominent lips. Each lip terminates in a pair of oral tentacles each of which ends in a knob-shaped cluster of nematocysts. In addition to these there is also a pair of knob-shaped clusters of nematocysts upon the sides ot each lip, centripetal to the terminal knobs. Medusa- buds are developed upon the sides of the manubrium about the region ot the stomach. These medusa-buds appear on interradially situated positions on the stomach-wall. According to Chun (1895, Bibliotheca Zool., pp. 20, 21) the order of development of the medusa-buds follows a very definite law. The oldest buds appear nearest the peduncle of the manubrium and the youngest are found 9 lower down nearer the oral tentacles. The accompanying dia- gram will serve to illustrate the law of succession in position and in time ot the various buds upon the manubrium ( I ) being the oldest bud and (16) the youngest (newest). The oldest buds are developed near the proximal base of the stomach, and the newest and youngest are found near the bases ot the oral tentacles. Even before they are set free the ,0 young medusa? begin to develop buds on their stomach-walls, '• and these secondary medusa-buds follow the same laws of time and place ot development as do the primary medusa-buds (see Chun, 1895, p. 23). Chun, 1895, showed that the medusa-buds were formed entirely from the ectoderm ot the manubrium, the entoderm taking no part in their development. As the bud becomes older, however, a connection is formed between its gastrovascular cavity and that of the mother medusa. The developing medusa-bud has, at first, only 4 radial tentacles, one at the base of each radial-canal. When set free, however, it possesses 16 tentacles: 4 clusters each ot the 3 tentacles at the bases of the 4 radial-canals; and also 4 simple interradial ten- tacles. The color of the entoderm of the manuhrium and tentacle-bulbs varies from brown- green to black. This medusa is common in the north Atlantic, where it has been taken off the coasts of Norway, Barents Sea, Helgoland, England, Ireland, Scotland, and New England. Fewkes found it in Narragansett Bay, Rhode Island, and it is common on the southern coast of New England in March. Browne records this species from Valencia Harbor, coast of Ireland. Levinsen, 1893, found it oflFthe west coast of Greenland. I believe that future studies will show that R. blumenbachu of the Black Sea is identical with R. octopunctata. The drawing of the oral tentacles of R. blumenbachu in Rathke's memoir is evidently diagrammatic and probably quite erroneous. R. blumenbachu appears to be merely an R. octopunrtata in an intermediate stage of growth wherein it has 3 tentacles in each of its 8 marginal clusters. ANTHOMKIHS K KATIIKKA. 170 Rathkea octopunctata var. grata A. Agassiz. Plate 18, fig. 5. Lmia grata, AGASSIZ, A., 1862, Proc. Boston Soc. Nat. Hist., vol. 9, p. 100, figs. 28, 29; 1865, North Amer. Acal., p. ihi, figs. 251-258.— NUTTING, 1901, Bull. U.S. Fish Commission, vol. 19, p. 376, fig. 91 .— HARGITT, 1904, Bull. U.S. Bureau of Fisheries, vol. 24, p. 39, plate i, fig. 4. \oti l.Kzia grata, FEWKES, 1881, Bull. Mus. Comp. Zix.1. at Harvard College, vol. 8, No. 8, p. 142, platf I, figs. 1-7. Margrllium gratum, HAFCKEL, 1879, Syst. der Mrdusen, p. 95.— LEVINSEN, 1893, Vid. Mi-ddrl. Nat. Fur. Kjnbenhavn (5), Bd . 4, p. 145. Adult medusa (plate 1 8, fig. 5). — Bell about 3.5 mm. in height and 5 mm. in diameter; pyriform in shape, and with well-developed apical projection which is solid. The gelatinous substance is thick at the apex of the bell, but thin upon the sides. There are 8 clusters of mar- ginal tentacles, 4 radial and 4 interradial. The radial clusters are each composed of 5 ten- tacles, while the interradial clusters contain only 3 tentacles each. The tentacles are long and flexible and are usually carried curled upward. The basal bulbs are large and filled with entodermal pigment-granules. The velum is well developed. There are 4 slender, straight radial-canals. The peduncle of the manubrium is long and extends about two-thirds of the distance from the apex of the hell-cavity to the velar opening. The gastric portion of the manubrium is small, and quadratic in cross-section. There are 4 prominent lips, each of which terminates in a pair of oral tentacles which end in knob-shaped clusters of nematocyst-cells. There is also found a pair of knob-shaped nematocystic clusters upon the sides of each lip. Medusa-buds are developed in the interradii upon the sides of the manubrium. The ento- derm of the tentacle-bulbs and manubrium is usually intense orange, but in some cases the stomach is sage-green and the tentacle- bulbs russet. Young medusa. — In a medusa 1.2 mm. in height there are 16 tentacles: 4 radial clus- ters each consisting of 3 tentacles and 4 sim- ple, interradial tentacles. The peduncle is long and has the shape of the frustum of a cone. The stomach is short and there are 4 simple lips which terminate each in a single No medusa-buds are yet to be seen upon the FIG. 93.— Rnlhken " kollikrri," = R. fasciculala, afti-r Crgrnbaur, in Zeit. fiir wissen. Tool., Bd. 8. knob-shaped cluster of nematocyst-cells. manubrium. I he medusa-buds upon the manubrium of the adult have at first only 4 simple tentacles, one at the toot of each radial-canal. At this stage there are also 4 small interradial tentacle- bulbs, which lack tentacles. It is not known what condition the medusa-buds may be in at the time of their liberation from the parent. This variety is probably an Arctic form. It appears in Newport Harbor, Rhode Island, and in Massachusetts Bay during February, and disappears before June. It is distinguished from the European and American /,. KM i is i \i> EMI > RS, 1862, Zoolog. Beitrag, p. 84, taf. 13, fig. lo. Bougaini-illia kotlikrri, LEUCKART, 1856, Archiv. fijr Naturgescli., Bd. 22, p. 24, taf. 2, fig. 2. ISO MEDUS.E OF THE WORLD. This large Mediterranean form is described in the synoptic table of species of Rathkca. Gegenbaur, i854(Generationswechsel und Fortplanz.bei Medusen, etc.. p. 22, taf. 2,fign. 1-9), raised the larva until it developed into a solitary hydroid, 0.5 mm. long, with 4 tentacles, each beset with a row of nematocysts. A horny perisarc covered the hydrorhiza. The stages of segmentation were studied by Metschnikoff, 1886. The egg is o.ii mm. wide and yellowish to white in color. The segmentation is total and equal, and results in the formation of an elongated, ciliated, one-layered blastula with a large, central, segmentation cavity. The ectoderm is formed by the cells which wander into the segmentation cavity by ingression from the hinder end of the larva. The medusa is quite common at Naples, Italy, during the winter. The bell is barrel- shaped with a flatly-rounded apex. It is 8 mm. high and 9 mm. wide. The marginal ten- tacles are highly contractile. There are 10 to 13 tentacles in each of the 8 clusters. Each FK.. <)).-- Rtitlikea ftiscicitlalti. From living and preserved specimens, hy the author. Zoological Station, Naples, Italy. A, Side view of medusa with tentacles strongly contracted. R, Tentacle showing ocellus. (', Ahoral view of manubrium. /), View of oral tentacle, contracted. tentacle bears an ocellus on its inner side. The oral tentacles branch dichotomously 7 times. Whenever the medusa is disturbed hy a mechanical shock the oral tentacles suddenly expand to their full extent, torming a network of filaments around the mouth, and thus it is seen that through this fortuitous reaction the medusa captures its prey. Such a reaction is remarkable, for in common with other medusae all other parts ot the animal contract when disturbed. The 4 gonads form horseshoe-shaped, swollen crescents with transverse furrows. Each crescent surrounds the point of entrance of the radial-canal into the stomach and the horns of the crescent are directed ahorally. There are thus 4 pcrraJial gonads. This being the only instance of perradial gonods seen in the anthomedusa?. Rathkea octonemalis Maas. Ralhkea aclonrmalis, MAAS, 1905, Craspedoten Medusen der Siboga Expedition, Monog. 10, p. 12, taf. 2, fign. 1 1, 12. ( ? ?) Lizzflla octella, HAECKFL, 1879, Syst. der Medusen, p. 84. Bell 5 to 6 mm. high, 4 to 5 mm. wide, with thick, gelatinous walls, bulging sides, and flat top. There are 8 clusters of marginal tentacles. 7 to 9 tentacles in each ot the 4 radial, and 5 to 7 tentacles in each of the 4 interradial clusters. These tentacles are not one-fourth as long as the bell-height, and there is a black ectodermal ocellus upon the inner side of each tentacle near the point of origin of the tentacle from the basal bulb. The 4 radial-canals and the ring-canal are straight, narrow, and simple. The stomach is mounted upon a short, wide, conical peduncle. The mouth is surrounded by 4 clusters of oral tentacles. Each cluster arises from a short basal stalk and branches dichotomously 4 to 5 times. The basal stalks of these clusters are so short and the forked branches so long that the mouth appears at first sight to be surrounded by 8 clusters of tentacles. This impres- sion is, however, erroneous, for there are but 4 clusters of oral tentacles. The mouth does not ANTHOMEDrS.-TC— RATHKKA. 1X1 extend to the level of the velar opening. The gonads are on the 4 interradial sides of the stomach. They are doubly cleft in each interradius so as to present the appearance of 4 longitudinal hands below, but are (used above, forming a double horseshoe. The tentacle- bulbs have decided red, entodermal pigment. The stomach is reddish-brown and the eggs appear as flecks of yellow. Found in the Malay Archipelago, Ternate, 3° 46' S. lat., 127° 47' long. E. from Greenwich. It is possible that Lizzt-lln nitflla Haeckel may be identical with this species. Haeckel gives a very brief description ot this medusa as follows : Bell egg-shaped, i 5 mm. high, 10 mm. wide. Stomach globular or almost cubical, about as long as its conical peduncle. Gonads 4-teathered leaves in the stomach-wall. 8 simple, unbranched, oral tentacles as long as the stomach. (Broken?) 8 marginal tentacle clusters, each with 8 long ten- tacles. Coast of Japan. Color ( ?) Rathkea elegans. Plate 1 8, fig. 4. Li-Kin elegant, MAYKR, 1900, Bull. Mus. Comp. Zool. at Harvard College, vol. 37, p. 44, plate 38, fig. 127. Bell 3 to 7 mm. in height and gelatinous substance of moderate and nearly uniform thick- ness. The sides of the bell are almost straight and vertical and the top is dome-shaped. There are 8 groups ot marginal tentacles, 4 radial and 4 inter- radial. Each radial group is composed of 4, and each interradial ot 3 tentacles. The tentacles are quite stiff and curve upward and are only about halt as long as the bell-height. There is a small, dark- FIC.. 95.- Rathkra octoiiemalis, after Maas, in Hydro- brown, ectodermal ocellus upon the under (velar) medusen XihaSa Expedition. sjde Qf each tentac|e near the l)asaj |,ujb_ Jht. velum is wide and provided with strong muscles. There are 4 straight, narrow radial-canals and a simple circular vessel. There is a well-developed, conical peduncle above the stomach, down which the radial-canals lead in their course to the gastric sac. The gastric part of the manubrium is cruciform in cross-section and pear-shaped in general longitudinal contour. The mouth is a simple opening without prominent lips. I he oral tentacles arise from 4 radial sides of the stomach at a short distance above the mouth. Each tentacle branches dichoto- mously 3 times, and then each tip terminates in 3 small branches which are covered with nematocysts. The entodermal cells of the oral tentacles are chordate. The genital products are situated upon the tour interradial sides ot the stomach. The entoderm of the tentacle-bulbs and radial-canals is ot an intense, opaque, pearl-- white color, often displaying a tinge of pink. The entoderm of the stomach is of an intense green, and the oral tentacles are pearly-pink. The intense opaque color of the radial-canals contrasting with the hyaline transparency of the bell renders this medusa one of the most beau- tiful found at the Tortugas, Florida. Several specimens were captured early in July, iS\ Dv ia hlandina, FORBES, 1848, British Naked-eyed Medusa-, p. 67, plat.- 12, fig. 4.— BI.DOT, 1905, Revue SUISM- 7..JC.I., Bd. I •„ p. H7 (literature 1X48-50).— BROWNE, 1895, Trans. l,ivrrp<»>! Biol. Sue., vol. 9, p. 265; 1896, 1'r.n . /on]. Sor. of Lon- don for 1896, p. 475 (review of recent literature, etc.); 1898, Journal M.ir ..... liiol ._ A •-. >. .. V S., vol. 5, p. rSX. (FORBES), BROWNE, 1896, Proc. Zool. Soc. London, p. 475 ia, s/>., CLAPAREDE, 1860, Zeit. fur wissrn. Zool., Bd. 10, p. 401, taf. 32, fign. i-}. marphesa minima (vounp stage)-!- Lizzia fltlparedei-^ L. blontlina, H*»rKFI, 1879, Syst. der Mr.luvrn. pp. -SI, 82, taf. 6, fig- 7- zia claparedei, CHUN, 1895, Bibliothi-ca Zoologies, Heft 19, p. 36 (budding of medusa-), figs. 2-4. HAK'KH.— Lizzia blonilina, FORBES, BROWNE, 1905, Proc. Roy. Soc. Edinburgh, vol. 25, p. 754. X,infd elhabetli,r, HAKCKKI., 1879, Svst. der Medusen, p. 83, laf. ft, fig. 12. 'inorphosa minima (young medusa), BROWNE, 1895, Trans. Liverpool Biul. Soc., vol. 9, p. 260. smorphosa minima, HAECKEI.= Lizzia claparedei, HARTLAUB, 1897, Wissen. Meeresuntersuch. Deutsch. Meere, Ntue Fol Abth. Helgoland, Bd. 2, p. 455.— HAECKFL= Lizzia clapandti, BROCII, 1905, Bergens Museum Aarbog, vol. u, p. Foltv, 5. IS'J MKnrs.E OF THF. WORLD. Mature medusa. — Bell 6 mm. high, 4 mm. wide. Pyriform. There are 3 tentacles in each of the 4 radial, marginal clusters and only one tentacle in each interradius. The stomach is mounted upon a short peduncle, and both together are hardly half as long as the depth of the bell-cavity. There are 4 radially placed, simple, unbranched, oral tentacles, each of which terminates in a knob-like cluster of nematocysts and is as long as the stomach itself. When immature the medusa produces medusa-buds upon the interradial sides of the stomach, but later, when there are 3 tentacles in each radial cluster, the budding ceases and ova or sperm develop. Claparede discovered that the eggs are inclosed in nematocyst-beanng capsules, reminding one ot'the condition observed in Bougainvillia superctliaris. Browne states that the medusa may become sexually mature when the bell is only 1.5 mm. high. The stomach, gonads, and tentacle-bulbs are amber-yellow. Found off the coasts of England, Ireland, Scotland, Germany, and Norway. When the medusa is young there are only 8 marginal tentacles, 4 radial and 4 interradial. Later there are 4 radial clusters, each consisting of 2 tentacles, and 4 smaller, isolated, inter- radial tentacles. Medusa-buds are produced upon the interradial sides of the stomach, when the medusa has only 8 tentacles. The 4 oral tentacles remain simple and unbranched through- out life. Lizzin eliztihftlicr Haeckel resembles R. blondina in all respects excepting that there are 4 tentacles in each radial, and 2 in each interradial cluster. Haeckel found this at Jersey, English Channel. May it not be R. blonJina with more than the usual number of tentacles ? Browne found a 3-rayed specimen of R. blonJina, with 3 radial-canals, j oral tentacles } clusters of "perradial" tentacles each containing 2 tentacles and 3 single interradial tentacles Genus CHIARELLA Maas, 1897. C\iiaTflla, MAAS, 1897, Mem. Mus. Comp. Zool. at Harvard College, vol. 23, p. 15. The type species and the only known form is Chiarella centripetalif Maas, from the Gulf of California, Pacific coast of Mexico. GENERIC CHARACTERS. Margelina? in which the ring-canal gives rise to blindly ending, centripetal diverticula, There are 8 cleft tentacle-clusters, so that the tentacles arise from 16 epaulet-shaped, marginal swellings. 4 of these cleft tentacle-clusters are radial, and 4 interradial in position. The oral tentacles are dichotomously branched. This genus is chiefly distinguished by the blindly-ending diverticula of the marginal ring-canal. The deeply-cleft tentacle-epaulets are quite characteristic, but this tendency is also seen in some species of Bougainvillia and can not he considered as being a distin- guishing characteristic of Chiarella, although it appears in a more marked degree in Chiarella than in Bougainvillia. Chiarella centripetalis Maas. Chiarflla centripelalh, MAAS, 1897, Mem. Mus. Comp.Zool. at Harvard College, vol. 23, p. 15, taf. 2, fign. 1-4; 190^, Craspe- doten Medusen der Siboga Expedition, Monog. 10, p. 13. Bell high and dome-like, 15 to 20 mm. high, 10 to 15 mm. wide. Gelatinous substance of slight consistency and fairly thick at apex, but thin at margin. Velum small. Bell-margin exhibits 8 adradial, lappet-like emarginations which alternate with the radial and interradial clusters of tentacles. The tentacles are very short, not more than one-tenth as long as the bell-height and arising from 8 medianly cleft, marginal, epaulet-shaped swellings. The median cleft in each tentacle-epaulet is so deep that the epaulet seems divided. 4 of these divided epaulets are radial and 4 interradial in position. In the mature medusa there are somewhat more than 40 tentacles in a single row on each double-epaulet, the medusa having altogether about 320 tentacles. These tentacles arise side by side from the margin of the epaulets, and the line of tentacles is continuous and not interrupted at the median cleft. There is an ocellus upon the margin of the epaulet, on the velar side, at the base of each tentacle. There are 4 straight-edged, narrow radial-canals and a ring-canal. This ring-canal gives off a short, pointed, blindly ending, centripetal diverticulum in each interradius above the median cleft of each interradial tentacle-epaulet. AXTHOMKIM S.K --< HIAHKI.I.A. 183 The stomach is barrel-shaped and about one-fifth as wide as the bell-diameter. It is not quite halt as long as the depth of the bell-cavity and is mounted upon a very short peduncle down which the 4 radial-canals extend to the base of the stomach. There are 4 railiulh placed clusters ot oral tentacles. Each cluster arises from a single stalk which branches dichotomously 5 to 6 times, thus giving somewhat more than 32 terminal ramuli in each quadrant. These terminal branches end in nematocyst- knobs. The gonads are 8 ad radial, linear swellings along the sides ot the barrel-shaped stomach. The entoderm ot the radial-canals and tentacle-bulbs is rose-red, as is also the deep-lying entoderm of the stomach. The gonads are dark-carmine and the ocelli dark-blown. Found in the (>ulf of California. Pacific coast of Mexico, by the Albatross in the spring ot iSui. Subfamily DENDROSTAURIN^, nov. subfam. li '.thiilm' his ± ll'iUiail-ri MAAS, 1904, Sitzungsbcr. math.-plivs. K|.ISM- kgl. Baver. Akad. Wissenschaft., Bit. 34, pp. 437, 458; Crjspeduten MI-I|UM-II der tibogti Expedition, Monog. 10, pp. 15, 19. — Bigeluvs, nio<;, Mem. Mus. Cninp. Zool. at Harvard College, vol. 37, p. 212. C.tinnrjliil.e (in part), HAI:CKK|-, 187*), Syst. der Medusen, p. 140. EH,. f)d.- -Clnnrella centripetalis, after M.I.I , in Mem. Museum Comp. Zoo], at Harvard College. SUBFAMILY CHARACTERS. Dendrostaunnae: Anthomedusae with 4 or more pri- mary radial-canals, some or all ot which branch. The 4 lips are without oral tentacles. The gonads are upon the interradial, or adradial, sides of the stomach. There are two tribes, Bythotiaridi and Williadi. The tribe Bythotiaridi was established by Maas, 1904, as the family Bythotiaridae (Sit /ungsber. inatli.-phys. Klasse kgl. Bayer. Akad. Wissenschaft., Bd. 34, p. 437; also, Cias- pedoten Medusen der Si/won Expedition, Monog. 10, p. 15). Maas pointed out its relation- ship to the Tiannae, which are exhibited most completely in the genus Bythotiara Ciiinther, wherein the gonads are exactly similar to those ot the Tiarm;i', the only essential difference being the branched radial-canals. The tribe Williadi as we define it is equivalent to the family Williadae of Forbes, Agassiz, Haeckel, Browne, Maas, and others. In 1904, lor. fit., Maas showed that the Cannotidae of I laeckel, 1879, was a heterogeneous group composed ot both Anthomedusae and Leptomedusx, and is, therefore, purely artificial and must be abandoned. \\ e will now proceed to define the tribes Bythotiaridi and Williadi and their »enera. CHARACTERS ()!•• THE TRINE HYTHOTI ARUM. Dendrostaurinx with branching radial-canals and a ring-canal. Without clusters of nematocysts upon the exumhrella above the margin between the tentacles. With hollow ten- tacles situated at the ends of the branches ot the radial-Canals. The - meilusii-, p. 727. Preboscidactyla ftavtctrrtitfi Tar. aolonifera, MAAS, iijo^, Cr.ivpeilnten Me,kisen ,ler .ViV'^/j Kipe,liti<>n, p. 21, taf. 4, fign. 24-28; 1906, Revur Suij-st- ,le /no]., liinit- 14, p. 89. Pryboscidaclyla omtita, vnr. stohniffiii, Bigelow, H. B., 11)09, Mt-tn Mus. Cnmp. X.uol. .it H.irvar,! College, vul. ^7, p. 220, plates 6, 41. Bell rounded, 5 mm. wide, 4 mm. high, with a low, dome-like, apical projection and thin walls. 12 to 20 or more tentacles, one at the base of each terminal branch of the 4 main radial-canals. These tentacles are about as long as the bell-radius and have large, spherical basal bulbs which bear entodermal pigment-granules. An equal number ot meridional lines ot nematocysts alternate with the tentacles. These au- upon the exumhrella and extend trom the margin about one-tilth to one-halt the distance up the sides ot the bell. There are a number ot clusters ot net- tling cells upon each line. The axial line is composed ot a core ot ento- dermal cells which branch off trom the solid cord ot entodermal cells which constitute the degenerate "ring-canal." The 4 mam radial-canals branch quite irregularly after the second fork- ing, so that 12 to 20, or more, canals reach the margin. The general mode ot forking is, however, similar to that of /•". rjniiitti. Medusa-bearing stolons develop at the second and thud tm kings ot each of the 4 radial-canals. There are thus 8 of these stolons, 2_in each quadrant. These stolons do not all develop at one and the same time. The two oldest appear at the second forks of the canals of one diameter, then the next two at the second folks ot the diameter 90° apart from the first, and then the 4 others follow in the same order at the third fork- ings of the canals. The stomach is wide, cruciform, and urn-shaped, as in other species ot the genus. I he 4 lips are recurved, and the manubrium is not longer than one-half to two-thuds the depth Fin. toi .—Proboscidoclyla orntiin i-ar. stolonifrrti, after M.i. iv, in Hr^t-h. Xihogit KxpeJ., Mnnog. X. 192 MEDUS.E OF THE WORLD. of the bell-cavity. The gonads may be pale green or colorless. The entoderm of the ten- tacle-bulbs is black, or pale green, or colorless. The gonads are upon the sides of the stomach and extend even beyond the first bifurcations of the radial-canals. It is found in the Malay Archipelago, and at Acapulco, Pacific coast of Mexico. This is identical with the medusa found by Huxley in the Louisiade Islands, North Pacific, and called P. tropica by Browne, 1904. In P. "• tropica" however, the medusa- bearing stolons arise from the first branchings of the 4 main canals and not from the second and third points of forking as in Maas' and Bigelow's form. Bigelow's studies have shown, however, that the two are identical, P. tropica being only a young stage. P. "tropica" has 16 terminal branches to its 4 main radial-canals. 16 short tentacles, 4 stolons at the points of origin of the first branches of the 4 main radial-canals. These stolons are long and end in a knob of nematocysts. On one side the stolon gives rise to a series of medusa-buds, the oldest being nearest the free lower end of the stolon. When about to be set free the budding medusa has 4 simple, unbranched radial-canals and 4 tentacles. Proboscidactyla ornata var. gemmifera. Plate 21, figs. 1-3. ll'illia ornata, BROOKS, 1880, American Naturalist, vol. 14, p. 670; 1881, Studies Johns Hopkins Univ. Marine Lab., vol. 2, p. 144. Il'illiit i>finmifera, FEWKES, 1882, Bull. Mus. Comp. Zoo], at Harvard College, vol. 9, p. 300, plate I, fig. 24. Proboscidaci\la pemmifera, MAAS, 1904, Sitzungsber. math.-phys. Klasse kgl. Bayer. Akad. der Wissenschaften, Bd. 35, p. 439.— BROWNE, 1904, Hydromedusa- Maldive Islands, p. 727. l)\*< unriotti ^emmifera, MAYER, 1900, Bull. Mus. Comp. Zool. at Harvard College, vol. 37, p. 47, plate 8, fig. 17. This variety of P. ornata is peculiar in that it gives rise to medusa-buds which are borne upon 4 stolons that arise from the radial corners of the stomach near the points of origin of the 4 main radial-canals. Several medusa-buds in various stages of development may usually be seen upon each stolon. When set free, each medusa has 4 simple, unbranched radial-canals, 4 well-developed, radially situated tentacles, and 4 small, interradial tentacle-bulbs. There are also 8 centripetal canals alternating with and intermediate in position between the tentacle- bulbs and tentacles. There are no medusa-buds or stolons upon the medusae when set free from the parent. All of the budding specimens of Proboscidactyla which have thus far been observed were in the Dyscannota stage, having 12 terminal branches to the radial-canal system and 12 mar- ginal tentacles. Each of the 4 canals which leave the stomach gives rise to 2 side branches, and thus there are 3 terminal canals in each quadrant; 12 in all. It is possible that after the medusa has ceased budding the canals may increase in number so as to become 16. On the other hand, P. ornata var. gemmifera, may never develop sex-cells or possess more than 12 canals. The common P. ornata, which lacks medusa-buds and has 16 tentacles and terminal canals, is found wherever the budding variety has been observed, although the budding variety is not known north of Beaufort, North Carolina, while the sexual form is abundant upon the southern coast of New England. For many years it was believed that in this gemmifera form there was constantly but a single cluster of nematocysts over each centripetal canal of the exumbrella, between the tentacles, whereas in the sexual P. ornata there might be i, 2, or occasionally 3, clusters over each canal. In 1903, however, I found two specimens of the gemmifera form which had I, 2, or 3 clusters of nematocysts over each centripetal canal, and therefore resembled the condition seen in the sexual P. ornata. No gonads have been observed upon the manubnum of the gemmifera form and the stomach is therefore smaller and more slender than in the sexual P. ornata. P. ornata var. gemmifern is found from Beaufort, North Carolina, southward to the Bahamas. On the whole its close similarity to P. ornata in the Dyscannota stage leads me to believe that it is only an immature or budding variety of Proboscidactyla ornata. Proboscidactyla "minima" Browne. Proboscidatiyla minima, BROWNE, 1905, Pearl Oyster Fisheries, Gulf of Manaar, Suppl. Report, Roy. Soc. London, 27, p. 136, plate 2, fig. 3. Bell hemispherical ( ?),o.75 to I mm. wide, with fairly thin walls. 4 main radial-canals with lateral branches. Number of lateral branches ( ?) 10 to 20 short tentacles 0.25 mm. long with globular basal bulbs. Stomach with 4 longitudinal lobes with the gonads upon their sides. Mouth with a sinuous margin. Clusters of nematocysts on the exumbrella near the PLATE 21. Fig. I. Proboscidactyla ornata var. gemmifera, showing a budding medusa about to be set free. Tortugas, Florida, June, 1897. Fig. 2. ProkosfiJtiftvln or tint a var. gemmifera, showing unusually dark pigment in the tentacle-bulbs. Beaufort, North Carolina, No- vember 21, 1904. Fig. 3. Proboscidactyla ornnta var. gemmifera, showing small immature medusa buds at the 4 radial angles of the stomach. Tortugas, Florida, June 12, 1897. Fig. 4. LaoJicea cruciatu ("calcarata"), young medusa. Agassiz Labora- tory, Newport, Rhode Island. Fit;. 5. Laodicea cruciatn ("calcarata"}, half-grown male medusa. Agassiz Laboratory, Newport, Rhode Island, September 17, 1896. Drawn from life, by the author. PLATE 21 \\Tllo\II-.hrs.K l'lf<>li(>SMl>\<"n LA, WII.I.SU. I'.lo margin between the tentacles, dull ot Manaar, neat Cevlon, in February. Color ( ?) Dis- tinguished by its small si/e (when mature ?). Proboscidactyla "occidentalis" Browne. Il'illia oecideataJis, FMVK*S, 1889, Bull. Kssex Inst., Salem, vol. 21, No. 7, p. 109, plate 5, fig. 3. Prabasriilarltla orciilrnlalis, BROWNF, 1904, Fauna and Geog. Maldive ami I.aciadive .-Wlnprlagors, vol. 2, p. 726. Size ( ?) Bell pyriform, gelatinous substance thick. 4 main radial-canals, each ot which gives rise to 2 side branches, which also branch; thus each main radial-canal reaches the mar- gin bv 5 vessels. 2O tentacles with reddish basal bulbs. Gonads on the marginal sides ot the stomach. 4 lips. A single cluster ot nematocyst-cells on the exumbrella between each suc- cessive pair of tentacles. Island ot" Santa Cruz. California. Color (''} Is this only a young stage ot P. flavicirrata : Genus WILLSIA Forbes, 1846. H'ilhiu.ls. I' lo K, viiiinR and rnaUirr st.igr nf H'illiia brooktii :,p. nm .; II.IVIMI; I. prinurv r.i.h.il-ran.ils, 24 lrrniiii.il r.iiniili- Fnmi Beaufort, North C.irolina. Drawn from lift-, by 1'rofi-ssor Brooks. 196 MEDUS.E OF THE WORLD. sented to me by the Department of Biology of fohns Hopkins University for publication in this work, and it seems but fitting that the species should be named in honor ot the great naturalist who discovered it. It is closely allied and possibly identical with the European ffillsia stellata, although the 3-rayed center of the stomach appears to distinguish it. In the young stage there are 6 simple, slender radial-canals, 60° apart. The beU-walls are relatively thin and the bell somewhat higher than a hemisphere with a bluntly pointed apex. The 6 tentacles are 5 to 6 times as long as the bell-diameter and have swollen, nematocyst-bearing, outer extremities. In the mature medusa the bell is flatter than a hemisphere, thick walled, with a shal- low bell-cavity. Twenty-four tentacles alternate with 24 exumbrella, nematocyst tracts each with several clusters of nettling cells. The manubrium has 6 lips. Stomach j-rayed at center, but each ray forks, giving 6 ramuli, 6 primary radial-canals which bifurcate twice giving 24 terminal branches. The gonads extend along the sides of the stomach. The size and color can not be determined from Professor Brooks's drawings. Found at Beau- fort, North Carolina. (See page 195.) Order LEPTOMEDUSJE Haeckel, 1866. Lefilomtduij-, HAECKEL, 1866, Gencrellen Morphologic, BJ. 2, p. Ivii; 1879, Syst. dor Meduscn, p. 1 1 1 .— BIGILOW, njo'j, Mem. Mus. Comp. Zool. at Harvard College, vol. 37, p. 147. — TORREY, 1909, Publications University California, Zool., vol. 6, p. 12. CHARACTERS OF THE ORDER l.EPTOMEDUS^E. Hydromedusae which arise by alternation of" generations from Campanularian hydroids. The gonads are developed upon the radial-canals. When present the lithocysts are of ecto- dermal origin. We may distinguish three families as follows: 1. Thaumantiadae Gegenbaur, 1856. Without lithocysts, but with marginal sensory- clubs or cordyli. 2. Eucopidx Gegenbaur, 1856. With lithocysts and with less than 8 radial-canals. 3. yEquoridae Eschscholtz, 1829. With lithocysts and with more than 8 radial-canals. The Leptomedusae are probably descended from the more simply organized Antho- medusae; this is shown by the fact that when first set free from the hydroid some of the Euco- pidae, such as Phortis,lzck lithocysts, which develop later. Also the hydroid of Eutinn called Campanopsis has nearly all of the characters of the Tubularian hydroids. Asexual production of medusa-buds is extremely rare in the medusa? of the order Leptomedusae being known only in Eucheilota paradox tea and Eirenc incJusifera. These medusae are therefore creatures of the coasts and are rarely found far out at sea, for they can not maintain themselves in situations unsuited to the growth ot their hydroids. Family THAUMANTIADjE Gegenbaur, 1856. Thaumantiada, GEGENBAUR, 1856, Zeit. fiir wissen. Zoo]., Bd. 8, pp. 218, 236, 268. — MAAS, 189}, Ergeb.der Plankton Exped., Bd. 2, K. c., pp. 64-65; 1897, Mem. Mus. Comp. Zool. at Harvard College., vol. 23, No. i, p. 19; 1905, Craspe- doten Medusen der Siboga Expedition, Monog. 10, p. 23. ThaumanliaJit+Cannolicif, HAECKEL, 1879, Syst. der Medusen, pp. 120, 140. FAMILY CHARACTERS. Leptomedusae without lithocysts. The gonads are developed upon or extend outward over the radial-canals and are not confined exclusively within the walls of the stomach. In so far as is at present known the Thaumantiadae develop through alternation of generations from Campanularian hydroids. For our knowledge of the development of the species constituting this family we are indebted to the researches of Wright, 1862, on Thau- mantias; A. Agassiz, 1865, on Melicertum; Metschnikoff, 1886, on Laodicea; and Browne, 1900, on Dipleurosoma. It is evident, indeed, that the Thaumantiadae are very closely related to the Eucopidae. They resemble the Tubularian medusae (Anthomedusae), however, in the absence of lithocysts and the prevalence of ectodermal ocelli upon the tentacle-bulbs. Indeed, all authorities agree in considering the Thaumantiadae as more lowly organized than the Eucopidae and /Equorid;p. LEPTUMEUL'S.E. 197 and probably nearly related to the forms from which the Campanularian medusae have developed (see A. Agassiz, 1865, pp. 124, 125; O. and R. Hertwig, 1897, Nervensyst. und Sinnesorgane der Medusen, p. 155; Haeckel, 1879, pp. 121, 125; Brooks, 1895, pp. 301-303). Haeckel goes so far as to state that the medusae of his genus Tetranema (fhaumantias) are the primitive forms from which the Campanularian medusa? (Leptomedusae) have been developed! Asexual budding of medusae upon the gonads is unknown in the Thaumantiadae. Brooks, 1895, shows that the marginal sense-clubs of Landicea contain no tract- of concre- tions. Their cores are entodermal and they arise from the level of the exumbrclla nerve- ring, above the velum, and are identical in all their anatomical relations with the sense-clubs of the Narcomedusae and Trachymedusae. Haeckel, 1879, includes Gomonemus and the Williadi among the Thaumantiadae. Gon ion emus is certainly not one of the Thaumantiadae, for it has marginal lithocysts; and according to the researches of Hincks, 1872, and Browne, 1896, the Williadi are derived from Tubularian hydroids and should be placed among the Anthomedusae. The Thaumantiadae may be conveniently, although somewhat artificially divided into three subfamilies: 1. Melicertinae, with simple, unb ranched radial-canals. 2. Polyorchinae, in which the radial-canals give rise to blindly-ending side branches, and these side branches do not fuse with the circular vessel. 3. Berenicinae, in which the radial-canals give rise to side branches, and these side branches connect with the circular vessel. A description ot the genera of the Thaumanriadie follows: SUBFAMILY MELICKRTINJE: With simple, unbranched radial-canals upon which the gonads arc developed. The lips are as numerous as the radial-canals. Ocelli, marginal sense-clubs, cordyli, and cirri are often present. There are no oral tentacles. Thaumantias ESCHSCHOLTZ, ifay^Tttranema+Thaumantias HAECKEL, 1879. 4 or more tentacles, 4 radial-canals, and 4 simple lips. No marginal clubs or cirri. Hydroid: Thaumantias, Laodicea LESSON, 1845= Qctenema+ Laodice HAECKEL, 1879. 4 or more tentacles, with marginal clubs or cirri or both between tentacles. 4 radial-canals, 4 simple lips. Hvdrmd: Cuspidelln. Mriirrrtum OK I;N, sfnsu AGASSIZ = Melicertellajr Mflirertum HAKCKKI, 1879. With 8 or more icnt.n lc-. S radial- canals, 8 simple lips, ami without marginal sense-clubs and cirri. Hydroid: Mflicrrtum. t\ffliffrtissti HAI.CKJL, 1^70. \\'iili S nr more tentacles. 8 radial-canals and X lips. With mariMn.il i , , cirri. This is equivalent tf>sia, TORRKY, 1909. Similar to Pol \orch is, but with a gastric peduncle and without pinnate branches on the radial-canals distal to the gonads. (See Appendix.) Xpirorodon HAKCKEL, i^jy^Goneomeantlrus, KIRKPATRKK, 190}. Similar to /'O/VOT/IIJ, but ring-canal gives, rise to blindly-ending centripetal branches and bell-margin divided into lappets. Development unknown. SUBKAMILY BIRHWICIN.'}-;: Radial-canals branch and all branches connect with circular vessel. Lips as numerous as main radial-canals. Ocelli, marginal clubs, and cirri often present. Cannota HAFCKEL, 1879. 4 main radial-canals each of which gives rise in 2 simple side branches, and thus 12 canals connect with the circular vessel. There are 12 gonads, I upon each terminal branch of the radial-canals. Curifria PERON, 1807 = Btrcn ice HAECKKI,, 1879. The 4 mam radial-canals give rise to non-dichotomoua side branches, and the side branches also branch. Gonads on the terminal branches of the radial-canals. Dichotomia BROOKS, 1903. 4 mam radial-canals all of which divide dichntonmuslv twu nr more times. Tin- extend outward from the sides of the stomach over the radial-canals and their branches. DipUurosoma AXEL BOF.CK, 1866 = Tttracannota MAVKR, 1900. "\ or more main radial-canals, some or all of uhuh give rise to non-dichotomous branches. Gonads on the canals adjacent to the manubnum. According to Browne, the hydroid appears to be Cuspidella? Toxorchis sens, emend., HAECKKL= Toxorcki$+ Cladotanna HAECKEL, 1X79. 4 or more main r.ult,il-t anal', u Inch branch dichotomously one or more times. Tin- gonads are upon the outer branches -.f the radial-canals near tin- circular canal. Netocertoitki M\YKR, 1900. 8 main radial-canals, which branch dichotomously. The gonads extend outward from tin- sides of the stomach along the radial-canals. L98 MEDl'S.E OF THi; WOULD. Genus THAUMANTIAS Eschscholtz, 1829. Tliaumiintia* (in part), EsciisnioLTZ, 1829, Svst. der Acal., p. 102. — OKEN, 1835, Allgemeine Naturgesch., Bd. 5, p. 226.— LESSON, 1843, Hist. Zooph. Acal., p. 176. — FORBES, 1848, British Naked-eyed Medusa, p. 45, etc. Thaumaniia!. GI.C.KNBAUR, 1856, Zcit. fiir wissen. Zool., Bd. 8, p. 237. — WRK;HT, 1862, Quart. Journ. Microscop. Sci., N. S., vol. 2, pp. 221, 308. — HINCKS, 1868, British Hydroid Zoophytes, p. 178. — BROWNE, 1896, Proc. Zool. Soc. London, pp. 480, 489. — HARTLAI B, 1905, Zoologische Jahrbucher, Supplement 6, p. 567. Ten ii'iniiii 4 ThaumantieiSf HAECKEL, 1879, Syst. der Medusen, pp. 125, 127. Halmomises, VON KENNEL, 1891, Sitzbcr. Nat. Ges. Dorpat, Bd. 9, p. 282. The oldest species is "Thaumantias hemispheerica" Eschscholtz, 1829 = Medusa In-nu- sfi/i.rru-a Gronovius, 1760; but Browne, 1896, shows that this is undoubtedly a Phialidium, and has lithocysts which former observers had overlooked. "Thaumantias aeronaut ica" Forbes, 1848, is probably a Pliinlitiiuni, and the type species appears to be Thaumantias fdlularia Haeckel = LaoJicc ccllularia A. Agassiz, 1862, 1865. GENERIC CHARACTERS. Thaumantiadae with 4 gonads upon the 4 radial-canals. With 4 or more tentacles. Manubrium without a peduncle and with 4 simple lips. No marginal sense-clubs or cirri. The hydroid is Thaumantias. Haeckel, 1879, would restrict Thaumantias to include medusae with 16 or more tentacles, and he proposed a new genus Tetrancma for medusae with 4 tentacles. We adopt a broader definition and restore the older interpretation of Forbes and others, and include medusae with 4 or more tentacles under Thaumantias. T/iaumantias is separated from Laodicea by the fact that there are no marginal sense- clubs or cirri in Thaumantias, whereas these structures exist in Laodicea. The hydroid of Thaumantias was first described by Wright, 1862 (Journ. Microscopical Science, vol. 2, p. 221). The stem is simple (or branched?) and rooted by a thread-like stolon; hydrothecae campanulate; polypites with a prominent funnel-shaped proboscis. The stem is sometimes ringed throughout, sometimes only at the base and summit. The calycles of the polypites are denticulate, the edge having about 7 teeth. There are 16 or more tentacles in a single ring. Wright reared the hydroid from the eggs of Thaumantias inconspicua Forbes. Thaumantias is unfortunately a receptacle for all the medusae of Phialidium in which lithocysts have not been observed. The older authors, previous to Gegenbaur's researches published in 1856, generally failed to observe the lithocysts; hence our heritage of numerous "species" of "Thaumantias." Browne, a most assiduous student of European medusae, recently stated that he had never found a Thaumantias. I have never taken one in thousands of surface-tows made along the Atlantic coast of the United States from Eastport, Maine, to Tortugas, Florida, nor did I find a single specimen of Thaumantias in cruising over the Pacific while serving as assistant to Dr. Alexander Agassiz. Dr. Lobianco, however, kindly permitted me to study some well-preserved specimens of a medusa collected by him at Naples, which I believe to be a Thaumantias. Thaumantias eschscholtzii Haeckel. Thaumantias esrlischoltzii, HAECKEL, 1879, Syst. der Medusen, p. 129, taf. 8, fig. 4. — LEVINSEN, 1893, Vid. Meddel. Nat. Foran., Kjbbenhavn, ser. 5, Bd. 4, p. 145. Bell flat and watch-glass-shaped, and 3 to 4 times as broad as high. About 10 to 12 mm. in diameter. There are 240 to 280 slender tentacles with globular basal bulbs which are provided with ocelli. The tentacles are about half as long as the radius of the bell. There are no sense-clubs or cirri upon the bell-margin. The velum is well developed. There are 4 straight, narrow radial- rii,. 102.— Thaumantias esrlischoltzii, after Harcki-l, 1879. I.KI'Tu.Ml.m S.K THAI MANT1AS. 1111. 1 canals. I he manubrium is very shallow and there arc 4 prominent, crinkled lips. The 4 gonads are thick and cylindrical and occupy the middle regions of the 4 radial-canals. Kach gonad is about halt as long as the radial-canal upon which it is situated. Coloi ' ?) This medusa is found upon the western coast of Greenland. Thaumantias rubrum. Chromalonema filmim, K> «*>•,, iss^, Hull. Mus. Cmnp. Xool. .11 H.irwr.l l'o]|i-j;i-, \ol. .(. \,,. s. p. ',05, lit;. 41. I'l.iii- i. Bell hemispherical and gelatinous substance thick. There are 12 to |f> short tentacles. No lithocysts, marginal clubs, or cirri. There are 4 straight, radial tubes. Manubrium shoit and there are 4 slightly crenulated lips. Gonads developed upon radial-canals adjacent tn manubrium. Each gonad is about one-third as long as the radial tube upon which it is situated. The ova are very conspicuous. The gonads and tentacles air i ed in alcoholic specimens. Found oft the New England coast by the United Stales Fish Commission in i SSo and iXXi. Were, the lithocysts destroyed by preservation in alcohol '. Si/.e i :) Thaumantias cellularia Haeckel. l.n'ldl'f ifilllLlf I/I, Af.ASSI/, A.. (Site;. Nnllll AllHT. Al.ll., ['. 12^. fit;*-. It . JIT M«-,|UM-M, p. 129. — Mi RBAI II .ill.t Siu AKh K, 1 90*, , \'T« . '/.>•• >\ . s,i, . I.. ,; vul. I, p. 172, plate 17, fijjs. 2-26. Hell thick, dome-like, about }O mm. wide, 20 mm. hiidi. About 100 tentacles \\ith wcll- developed basal bulbs set closely one by the side ot the other. Tentacles about as Ion" as the hell-diameter. Stomach very small and with 4 long, slender, folded lips, 5 to to 24 very long tentacles with well-developed basal bulbs, which contain a simple ring of pigment upon their outer (centrifugal) sides. There are no marginal am. I he velum is well developed, being broad and thin. The manubrium extends horn the inner apex of the bell- cavity to the level of the velar opening. It is cruciform in cross-section, with a wide proximal base. The mouth is simple, with 4 small, bluntly rounded lips. The 4 radial-canals are sinuous for the first three-fourths of" their length from the 4 corners ot the stomach. In the last quarter ot their length, near their point of juncture with the circular tube, they are sti aight and narrow . The canals are broad in the sinuous region and here the gonads are situated. Kach gonad is longer than the portion of the canal upon which it is situated, and it is therefore thrown into frills and twisted sinuously. The bell is hyaline or fainth velhmish. The tentacles and bell- margin are slightly milkv. The gonads aie jrellowish-brown. if, MKDU.S.E OF THK WOULD. This medusa was discovered by von Kennel in a fresh-water lagoon on the east coast of Trinidad, south of Mayaro Point, in a cocoanut plantation. The water in which it was living was apparently perfectly fresh, not being salt to the taste. The lagoon was in commun- ication with the sea during the rainy season. Thaumantias maeotica Ostrooumoff. Thaumantias rnxolicu, OSTROOUMOIT, 1896, Bull. Acad. Imperiale des Sci. St. Petersbourg, bcr. 5, tome 4, p. 401, plate i, figs. 2, 4. S- Bell fuller than a hemisphere, with very thick gelatinous substance; 18 mm. wide, 10 mm. high. 32 filiform, slender tentacles, twice as long as bell-diameter, with well-developed basal bulbs. Dark-colored ectodermal ocellus on each tentacle-bulb. Velum narrow. 4 straight, slen- der radial-canals. Manubnum 4-sided, prisma- tic, with 4 simple lips. About half as long as depth of bell-cavity. No peduncle. 4 spindle- shaped gonads on the middle thirds of the 4 radial-canals. Sea of Azov, Russia. Dr. S. Lobianco of Naples kindly permitted me to study some very well-preserved specimens of a Thaumantias which he collected in the Bay of Naples. At first I was inclined to regard these as a new species, but now believe that they may represent a young stage of Thaitmantias micotica. I herewith present a cut (fig. 103) representing the largest of Dr. Lobianco's specimens together with the following description: Bell 4 mm. high and of about an equal width. Apex evenly rounded and exumbrella smooth. Gelatinous substance thick at apex, but thin at bell-margin. Bell-cavity about two-thirds as deep as the height of the bell. There are not more than 16 tentacles; the number among six specimens observed by me ranged from 8 to 12. The 4 perradial tentacles are about twice as long as the bell-diameter, the 4 interradial about half this length, and the adradial tentacles are not more than one-third as long as the interradial. All of the tentacles taper gradually to their tips and are sharply set off from their globular, swollen, basal bulbs. There is a black, abaxial, ectodermal ocellus upon each basal bulb. The shaft of each ten- tacle is regularly besprinkled with small, isolated, wart-like patches of nematocyst-cells, which do not form rings. Velum very wide. There are 4 straight- edged, narrow radial-canals and a simple, slender ring-canal. Manubnum small, flask-shaped, and I'll.. 103. — Thaumantias with 4 simple lips. It is not more than one-fourth as long as the depth of the bell-cavity. The 4 spindle-shaped gonads are developed along the 4 radial-canals from their proximal thirds to their middle points. They are apparently immature. The collection of the Stazione Zoologica at Naples, Italy, contains six well-preserved, alcoholic specimens of this medusa, which were gathered by Dr. Lobianco in the Bay of Naples. This medusa bears some resemblance to Thaumantias quadrata Forbes, 1848, British Naked-eyed Medusae, p. 43, plate 9, fig. 2; from Loc Fyne, Scotland. In this British medusae, however, there are apparently no true ocelli, the so-called ocelli of Forbes being orange- colored entodermal pigment in the tentacle-bulbs. PLATE 22. Fig. i. Disi'jiifinti tiirriJa, mature male. Tortugas, Florida, June 21, 1907. Figs, i to 4. LnrjJici-a cruciatn (" calcarata"). Successive stages in the development ot' the medusa. Agassiz Laboratory, Newport, Rhode Island. |une to September, 1892. Fig. 5. Laodiccn cntciata ("calcarata"). Part ot" the hell-margin of the medusa shown in figure 4. Fig. 6. Laodicfii iriiciritii ("i nlcanita " ). Details of the gonads and manu- bnum of the medusa shown in figure 4. Fig. "J. Staurodiscus tctnistaunis, young medusa. Charleston Harbor, South Carolina, September 14, 1897. Fig. 8. Staurodiscus ti-ti-astunnis, young medusa. A sense-club from the bell-margin. See page I in tor description ot figure I. Drawn from life, by the author. PLATE 22 Pf-frf? I 3.- f .>"/•/ I.LTTuMKIHs F. LMHHiT.A. 2(11 Genus LAODICEA Lesson, 1843. l.,ia,li,ea, Lissov, 1X4;, Hist X.uoph. Aral.. i>. 21(4. \- VGA '•' m L. VcASSIz's, 1X1,2. Coin. Nat. Hi-t. I". S.. \.,l. 4, p. 550. -Ac.Assi/ and \U\ IK, 1X99, Bull. Mils. Comp. /ool. at Harvard College, \,.l. ;2, p. ifu. H«K..III. 1904. Bull. I .S. Bureau of Fisheries, vol. 24, p. 4^. C.OSmftir.I, FoRKts, 1X48, British Naked-eve, ! Me. in- r, p. 42. Thnuman'iai, GFC.SNBAI R, 1856, /cit. fur uissen. /mil., Bd. 8, p. 257. /., :lfll,i (hvdroid), HINC-KS, ]S6X, British Hvdroid /.ooph.. p. 201). plate 40. Oelonema+ LaoJice, H^KKM, iS^, Svst. der Medu en. pp. 121"), 1^1. /.uoilicr, MfTscHMKoth, iS8d, Embrvul. Studien an Medus.-n, \\ien, p. 23, etc. (development). -BROOKS, 1895, Journal Morphology, vol. 10, p. 287.— BKOWM, 1896, Proc. Zool. Soc. London, p. 4X2; IhiJ.. iX.jX. p. *2;. \K*s. 1904, Result. Camp. Sci. Prince de Monaco, Fare. z8, p. 18; 1905, Dii c ,, r> loten Meduaen der 5/laj/i Kxpedition, Monoj;. 10, p. 24.— BF.DCIT, 1901, Revue Slliutt d.- /o,,l., tome (). p. +S;; /I,,,/., i,,o;, tome i;, p. i ;(. (,-ii.ni,,n ,,f all n 1X^0). -BKCUVNJ, l'io^. Annals and Mag. Nat. Hist., vul. 20. str. J, p. 4s"'|. (lenu< \, MAAS, |X<(;, Hvdromedusen Plankton Kxpedition, p. ^5. (t< >fjr fift,!//,'!, \ os. LENDENPELD, i XX 4, Proc. Linnean So. . \. • South NV.de-, vol . iJi,,i of Ceylon, and /.. innrntnn ot the Fip Islands are only local races ot /.. crnciiitn ol the Medi- terranean and Atlantic coasts of Europe. All of these so-called species are possibly only im- perfectly differentiated local races of I.dic?n ,iiicnitii. Browne, iSi/i, iSc^S, has shown that the common Mediterranean, European, and American Laodicea are probably one and tin- same species, and my own studies serve only to convince me of the correctness of bis view. As in T mri>f>sis the species ot Laodicea tall into two well-defined groups: 'I hose \\ith 410 8 tentacles, represented by /.. ,-;/, o/v, f,-rlilit. nrptuiin. and ^•liitinn^i. and those \\ith ^2. to 300 tentacles, represented by /,. friitintu, chapmani, and pnLhrn. Metschmkoft, 1886, made elaborate studies ot the development of the egg of the J.nnJi. -, -it criictntn of the Mediterranean; and he succeeded in rearing the lar\;e until tlu-\ developed into small hydroids of the genus Cuspidella Ilincks. Laodicea cruciata L. Agassiz. Plate 21, figs. 4 and V: plate 22, tit;*. 2 to d; plate 2;, f\^. I to ;. i.iwtiiffa fiilcnrtiiti, A. Anssi/, m L. A(,ASSI/'S. i SI.2. t'ouf . Nat. Hist . r . S., \ol . 4, p. ^o. H ARC. ITT, 1904, Bull. I'. S. Bureau of Fisheries, vol. 24, p. 4^, i fit;. -.\!A\S, 1405, t'raspedoten Me.lusen ,ler Xit>og,i Expedition, Alonoi;. 10, p. 2?. l.tifn'il rornittti, AciASSlz, L., 1862, Con:. Nat. Hist . I . S.. vol. 4, p. ^51 (non I., i i/rnulii, Lamouroux). A<.\ssi/, A., iMi;. I' Boston Soc. Nat. Hist., vol. 9, p. 91, fii^. 4. Caiapanularia ilumoia, LFIDV, iX^s, Marine Iim rr. Fauna of R. I. and N. J., p. f,. l.a\a'a rulctirata, ACIASSIZ, A., iXti^, North Amer. Acal., p. 122, figs. 184, 194. l.tioilice calfaratti, H\M KM , 1X79, Syst. der Metlusen, p. 1^4. Bkooks, i Si)^, j.iurn.il of Morpholoi;\ , vol. 10. p. :X~. plate 17, figs. 5-7. — BROWM, iXtj^, Trans. Liverpool Biol. S..L., \,,1. 9, p. 276; 1898, Proc. Zoo]. s(ll . London for iXt>~, (• plate 49, fig. 4; 1000, Proc. Royal Irish Acad. Dublin, ser. ;, vol. ;, p. 720. I.afufii r,ilf,ir,a,i, VIRRIM., 187',, Report Commiss. Fish and Fishen. tot iS-i -2. p. 729. 202 MKI>U,S.) Medusa ttquorea, BASTF.R, 1759, Opuscula subseciva, n, p. 55, taf. 5, fign. 2, 3. ( ?) Medusa crutiala, FHRSKAL, 1775, Descript. anim., p. 1 10, taf. 33, fig. A. Thaumaniiai unaulata, FORBF.S and GOODSIR, 1853, Trans. Roy. Soc. Edinburgh, vol. 20, p. 313, plate 10, fig. 7. Thiiuiiiantias medilerranea, GEGKNBAI'R, 1856, Zeit. fur wissen. Zool., Bd. 8, p. 237, taf. 8, fign. 1-3. l.aodi(e cruciata, AGASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 350. — HAECKEL, 1879, Syst. der Medusen, p. 132 (a list of bibliography). — BROWNE, 1896, Proc. Zool. Soc. London, p. 483 (a good discussion of the literature). GRAEFEE, 1884, Arbeit. Zuol. Inst. \Vien, Bd. 5, p. 357. — METSCHNIKOFF, E., 1886, Embryologische Studien an Medusen, \Vien, pp. 23 (egg)> 37 (segmentation), 57 (formation of entoderm), 83 (polypite), taf. 4, fign. 17-31; ta'' 5- ^S- '• ( r) Laodice pulchra, BROWNE, 1902, Annals and Mag. Nat. Hist., ser. 7, vol. 9, p. 280 (Falkland Islands). Laodicea cruciata L. \a.= Thaumanlias medilerranea GEGENCAUR; METSCHNIKOFK, E., 1886, Arbeit. Zool. Inst. \Vien, Bil . n, p. 239. C.osmrlira ialinarutn, or PLESSIS, 1879, Annal. Mag. Nat. Hist., London, vol. 3, p. 385 (=£. cruciata). Laodice salinarum, HAF.CKEL, 1879, Syst. der Medusen, p. 636 (from the salt ditches of Montpellier, Mediterranean coast of France). Laodice cruciata, BEDOT, 1901, Revue Suisse de Zool., tome 9, p. 483; Ibid., 1905, tome 13, p. 136 (all papers cited to 1850). Hebella calctirala, THORNEI.V, 1905, Report Pearl Oyster Fisheries of Ceylon, Roy. Soc. London, Part 2, p. 1 16 (hydroid from the Gulf of Manaar, Ceylon). Laodice calcarata, etc., BROWNE, 1907, Annals and Mag. Nat. Hist., vol. 20, ser. 7, p. 460; Cuspiae/la (hydroid), Ibid., p. 463. It is difficult to determine the correct name of this medusa. Medusa cruciata Forskal, '775' 's so vaguel.V described and figured that it will never he possible to determine its true relationships, and this is also true ot Medusa crrjuorcu Baster, 1759. FH.. 104. — Laodicea " mediterranean after Gegenbaur, in Zeit. fur wissen. Zool., Bd. 8. Oral and side views of medusa and part of bell-margin showing tentacular spurs. Thaumanttas mediterranea Gegenbaur, 1856, is evidently a Laodicea, and is the same medusa which L. Agassiz, 1862, and Haeckel, 1879, call Laodice cruciata. Browne, 1896, 1898, inclines to the opinion that L. calcarata, L. ulotlin\ and Thaumantias mediterranea = L. cruciata L. Agassiz and Haeckel. and are one and the same species. My studies of Laodicea "calcarata," which is very abundant along the Atlantic coast of the United States south ot Cape Cod, has convinced me that it is identical with Laodicea cruciata of Europe, and is also distributed widely over the Pacific, where it has been called L. marama and L. indica. The extreme variability in color and in the development of the marginal appen- dages has caused much confusion in the naming of this most abundant and widely spread medusa. The old name L. cruciata takes precedence over "calcarata" and should supersede it, being, indeed, synonymous with it, but nevertheless the identity between this medusa and "Medusa cruciata" of Forskal must remain in doubt. It seems advisable, however, to retain an old and familiar name rather than to reinstate an unfamiliar one such as /,. undulata, which is the specific name given to this medusa by Forbes and Goodsir, 1853. Adult medusa (plate 22, fig. 4). — The bell is about 20 to 25 mm. in diameter, and when fully expanded it is somewhat flatter than a hemisphere. Being very flexible, however, it assumes all sorts of distorted forms under the influence of contraction. The gelatinous sub- stance is not thick at the apex and becomes regularly thinner toward the margin. There are /o to 150, or more, long tentacles, the ends of which are usually coiled in a close helix, while the main shaft of each tentacle is quite straight and rigid. The basal bulbs of the tentacles are large and hollow and often have abaxial spur-like projections; and there is a dark-brown or 1. ATE Figs. I and 2. LnoJii'i-n friu'iutti var. ulothnx. Successive stages in the development <>t the medusa, Toriugas, Florida, June, i8q~. Fig. 3. Lnndui-n cr tic nit n var. itlntlin\. Oral \'ie\v ot gonads of a female medusa. Nassau Harbor, Bahamas, June, 1903. Fig. 4. Mt'liiiTtuin campanula, young medusa. Nahant, Massachusetts, May 6, 1898. Fig. 5. Melicertum campanula, mature male. Marblehead, Massachusetts, |ul\- n, i goo. l^rawn from lite, bv the author. I.KI'TOMKIM s i; I.AOIiHT \. 203 purple ocellus situated within the ectoderm of the inner (centripetal) side of" most of the ten- tacle-bulhs. There are a number of coiled cirri scattered between the tentacle-bulbs (plate 22, fig. 5). These are usually somewhat less numerous than the tentacles. They arise at a short distance above the bell-margin on the exumbrella suit- of the bell. The con- of each cirrus is made up ot highly vacuolated entoderm-cells which are continuous with the entoderm of the circular canal. Numbers of spindle-shaped nematocyst-capsules are found in the ectoderm at the distal end of each cirrus. In addition to the cirri there are one or two clubs, or cordyli, between each successive pair of tentacles. The distribution of these cordvli is \ery irregular, but they are usually somewhat more numerous than the tentacles. Kach club is flask-shaped and united to the bell-margin by means of a narrow neck. They arise from the side of the exumbrella at the level of the upper nerve-ring, a very short distance above the level of the velum. The core ot each sense-club is composed ot large, highly vacuolated, entodermal cells which are directlv continuous with the entoderm of the circular-canal (see Brooks. lS<;5. plate 17, fig. 5!. The Fin. 105. — Ltloilicen rrntitita (ulolhrix *, .ifti-r Bnxik-. in ["iini.il i>f Mi.rpholni;\ , Vnl. 10. A . Srai«n nl trnt.ulr. />. Sriinm nf tini- of tin- marginal (.luh-.. clubs are not solid tor there is usually a small intercellular lumen in the axis ot the broad distal end of the club. There are no concretions. The velum iswell developed. Thereare4straighr, narrow radial-canals. The stomach is short and quadrangular in cross-section, and there are 4 recurved, slightly crinkled lips. In fully grown individuals the gonadj. extend from the sides ot the stomach down nearly, it not quite, the entire length of the radial-canals. The medusa is very variable in color, some individuals being nearly colorless. In otheis the entoderm ot the manubnum, gonads. and tentacle-bulbs is green or pink, and the entoder- mal lamella ot the bell is ot a delicate green, while in otheis the entoderm is milky or dull translucent yellow. This medusa is common along the coast of the United States from June to early winter. along the southern shores of New F.ngland to Cuba and the West Indies, but it has not been taken north of Massachusetts Bay. It ranges into more northerly latitudes off the European coast, however, tor Browne took it in Valencia Harbor on the southern coast of Ireland. It is seen in the Mediterranean from October to December, and is found in the Fiji Islands, JIM MEDUSAE OF THK WORLD. and Ceylon, in the Pacific and Indian Oceans. It is common only near coasts, not being a creature of the open ocean. It appears to be tar more abundant off the coast of America than in European waters. I found it only occasionally at Naples during the winter of 1907 08. The development has been studied by MetschnikofF. The early stages are described for the Mediterranean L. cniciata. The egg is 0.18 mm. in diameter and is laid between 4 and 5 in the afternoon from November to December. Segmentation is total and equal; and an oval, hen's-egg-shaped, ciliated, one-layered blastula is formed. Sometimes one sees a slight tem- porary invagination at the narrow hinder end of the blastula, but this is not the beginning of the formation of the entoderm. The entoderm on the contrary is formed from numerous cells which migrate individually into the large central segmentation cavity from the hinder end of the hlastula. The resulting planula swims about for a time, but finally it attaches itself and becomes a creeping, root-like, slightly branched hydrorhiza. from which there arise unbranched polypites "resembling Cuspidella humilis or Cuspidella costata Hincks." The hydrotheca is long and subcylmdncal, and the margin is provided with sharp-pointed teeth, and the polypite may withdraw within the hydrotheca and close the opening by the folding together of these teeth. The polypites have flaring, open, urn-shaped penstomes, below which there is a zone of jolong, slender, filiform, nematocyst-studded tentacles, all of about the same length. Browne, 1907, states that Miss M. Delap, of Valencia Island, off the southern coast of Ireland, maintained a colony of Cuspidella costata Hincks alive, and obtained from it young medusa; which resemble the youngest stages of Laodicea calcarata found in the Ocean. It is probable, therefore, that the hydroid described by A. Agassiz, 1865, as I.afira calcarata and which he believed to be the nurse of LarjJicea is not such. It lacks the toothed operculum found in Cuspidella and the margin of the hydrotheca is simple and entire. The direct embryological evidence demonstrates that the hydroid of Laodicea is CuspiJellti Hincks. Tabular Synopsis of the "dinettes" of Ltiotliceii cruciiitn. L.cruciata according to L. calcarata according to mv L. ulothrix, L. marama L. Jndica Haeckel, 1879=1*. studies. according to Agassiz and Browne. mediterranea Gegen- Haeckel, Mayer. baur, 1856. Brooks, and Mayer. Shape and dia- Flat. 20 to }o Flat to hemispherical. 20 to 25 Flat to hemi- Flat. 5.5 Flat. 5106 meter of bell spherical. Cyoung). in mm. 20 Number of ten- 100 to 120 with ocelli and 75 to 1 50 or more. Some with, 7010 looasin 50 as in L. cal- 60 to 80 with tacles. basal spurs. some without, basal spurs or L. "calcar- carala. large ocelli ocelli. Ocelli very variable in ata." and no basal size and number. Spurs some- spurs. times entirely absent. Arrangement Clubs and cirri more nu- Clubs and cirri sometimes more, As in L. "cal- As in L. "cal- As in L. "cal- and charac- merous than tentacles sometimes less, numerous than carata." carata." carata." ter of margi- and irregularly scattered tentacles. Sometimes quite nal appen- between them. regularly arranged, hut usually dages. irregularly placed. Character of Frilled and developed More or less frilled. Sometimes AsinL."cal- Immature. Immature(?). gonads. along entire lengths of mature when only about two- carata." Only half as Only half as the 4 radial-canals so as thirds as long as radial-canals; long as long as to touch ring-canal. sometimes developed over entire radial- radial- lengths of radial-canals. canals. canals. Color. Very variable. Stomach, Verv variable, as in L. cruciata. Variable, but Blue to green. (?) gonads, and tentacle- rarely so bulbs faint red, purple, brilliant as blue, brownish, violet, in northern etc. examples. \Vhr-Tf fniind. Mediterranean and Atlan- Atlantic coast of United States. Canary Fiji Islands, Ceylon, Indian tic tiiavts of Europe. Boston Harbor to West Indies. Islands, South Paci- Ocean. Bahamas, fic. Tortugas. I.KITOMIJHS 1. 1. \.iDK EA. When set free the medusa usually has 2 long tentacles, 2 well-developed hasal bulbs, and 4 small interradial swellings upon the bell-margin. At this time tin bell is about I nun. in height and about 0.7 mm. in diameter (plate 22, rig. 2). Its outer surface is covered with nematocyst-cells. There are only one m two marginal clubs or cirri in the young medusse. There are, however, well-developed ocelli within the ectoderm of the inner (centripetal) side of each tentacle-bulb. The 4 radial tubes are straight and narrow and thegonadsare repre- sented by 4 scarcely perceptible swellings adjacent to the sides of the manubiium. The manubrium is a simple tube with 4 small cruciform lips. As development proceeds the tentacles increase in number, as do also the clubs and cirri. The bell becomes relatively flatter until it approaches a hemisphere. The gonads begin to develop at the angles ot the manubrium and soon grow down the radial-canals until they extend to the circular canal. The manubrium acquires 4 recurved folded lips. A synopsis ot the so-called varieties ot /.. cruciatii such as is given on page 204, may be ot service in illustrating that we have here only one species. Laodicea fijiana Agassiz and Mayer. l.auJirta fjiana, AIMSSIZ, A., ami MAYFR, 1899, Bull. Mus. C'nmp. /mil. at Harvar.l (.'"llcgc, Mil. ',2, p. 163, plate 3, figs. 9, lo. I.aotlift fijtana (var. intiim '). MAAS, 1905, CYaspr.lotcii Mrdiibrn r>l.. Munog. 10, p. 25, taf. 2, fign. 14, 15, taf. 5, fij>n. 32-35; 1906, Revue Suine de Zool., tome 14, p. Xy. BKHWM , 1907, AnnaU ami Mag. Nat. Hist., SIT. 7, vol. 20, p. 467; L. maasi, p. 466. Bell 12 to 20 mm. wide, 4 to 5 mm. high. Bell-walls, although thin, quite rigid. 1 60 ten- tacles. These are flexible, tapering, with coiled ends, and are about as long as the bell-radius. About half to three-fourths of the tentacles have a dark-brown ectodermal ocellus upon the inner (axial) sides of their basal bulbs. There are a few clubs on the margin between the ten- tacles; about 12 to 15 in each quadrant in a large medusa, but only about 2. in each quadrant in specimens 6 mm. wide. There are no cirri between the tentacles. The stomach is square in cross-section, very flat, and without a peduncle. It is about one- fourth as wide as the bell-diameter and the lips are widely open, their folded edges inclosing an open square. The gonads are developed upon the proximal parts ot the 4 radial-canals and grow out- ward from the angles ot the stomach, so that in large medusae they may extend over two-thirds to seven-eighths of the length of each radial-canal, nearly touching the ring-canal. They are developed upon numerous short side branches of each of the 4 radial-canals, so that they are complexly folded and quite wide. In the female the ova stand out prominently over the surface of the ectoderm. The outer portions of the 4 radial-canals, which lack gonads, are straight and narrow and of the same width as the circular vessel. The entoderm of the stomach, tentacles, and radial-canals is opaque and milky-blue in color. Common on the surface in the tropical Pacific, Fip, and Malay Archipelago. It apparently does not descend into deep water. In large medusz the wide, flat, open stomach recalls that of /}t\; liog,-mi. Maas found a single specimen with 5 lips and 5 radial-canals, and others had 5 or (i canals. This \aiiability recalls the condition characteristic of Dipleurosoma. Laodicea pulchra Browne. l.aoAict pulclira, BROWNE, 1902, Annals ami Mag. Nat. Hist., ser. 7, vol. 9, p. 280; Ibid., vol. 20, p. 466. Umbrella flatly curved, 25 mm. wide, 15 mm. high. About 50 tentacles without basal spurs. No marginal cirri, but j or 4 clubs (cordyli) between every two tentacles. Kach cor- dylus situated on a small bulb. An ocellus is usually found at the base ot every tentacle and cordylus. The stomach is very large with 4 large perradial lobes extending nearly to the margin of the umbrella. The mouth has 4 large lips. The gonads extend from near the stomach to within a short distance of the ring-canal. Found at Stanley Harbor, Falkland Islands, from November to February. Color ( ?) Briefly described, without figures. b\ Browne from specimens obtained by Vallentin. May this not be identical with crncidtfi ? L'IMi MKDrS.E OF TIIK WOIJJ.D. Laodicea? neptuna Mayer. Plate 26, figs. 1-3. f.imlirra ntfiluna, MAYER, 1900, Bull.Mus. Comp. Zoo!, at Harvard College, vol. 37, p. 48, plate 10, figs. 50-51.— BROWNE, 1907, Annals an. I Mag. Nat. Hist., ser. 7, vol. 20, p. 469. Immature medusa (?). — Bell little higher than a hemisphere and 2.5 mm. in diameter. There are 8 short tentacles with large basal bulbs and 8 small, rudimentary tentacle-bulbs. Tentacles thickly covered with nematocysts and usually carried coiled and contracted. A single, large, black ocellus is found at the base of" each tentacle (plate 26, fig. 3). There are numerous small nematocyst-bearing cirri but no sensory-clubs upon the bell-margin between the tentacles. The velum is well developed. There are 4 straight, radial tubes, the upper regions of which, adjacent to the manubrium, are occupied by the gonads. The manubnum reaches slightly beyond the velar opening and the lips are surrounded by 4 prominent clusters of nematocyst-cells. The color of the entoderm of the manubrium, tentacle-bulbs, and circular and radial tubes is pearly-white. The entodermal lamella of the bell is of a delicate shade of green. This medusa was occasionally found at the Tortugas, Florida, during July and August, 1898. It has not been seen since that time. I can not be certain that this medusa is a l.aodicea and share the doubts expressed by Browne, 1907, upon the subject. Laodicea? eucope. (Irtonemti eitrv[>?, HA ECKEL, 1879, Syst. der Medusen, p. 127. — BROWNF, 1907, Annals and Mag. Nat. Hist., vol. 20, ser. 7, p. 477. Bell hemispherical, 8 mm. wide. 8 equal tentacles, somewhat longer than the bell- diameter and with thick, globular, basal bulbs sharply set off from the long, delicate shafts of the tentacles. An abaxial ocellus with a subspherical lens on each tentacle-bulb. fio to 80 marginal clubs. 30 to 40 spiral cirri as in Laodicea cruclata. 4 radial-canals. Stomach with 4 short, slightly-folded lips. 4 ribbon-like, folded gonads extending along the entire lengths of the 4 radial-canals. Color ( ?) Honolulu, Hawaiian Islands. The presence of abaxial ocelli may necessitate the removal of this medusa from the genus Laodicea, Laodicea? fertilis. Ortorliofiiilon f<-'ii(i\, VON LENDENFELD, 1884, Proc. Linnean Soc. New South Wales, vol. 9, p. 919, plate 42, figs. 14-15. — BKOW\F, i 907, Annals and Mag. Nat. Hist., ser. 7, vol. 20, p. 478. Rell semi-ovate, 2.5 mm. high, 2 mm. wide. Stomach a 4-sided pyramid, widest in the middle, "octaedral." 4 simple lips. 8 tentacles, 4 radial and 4 interradial; longest tentacles two-thirds as long as bell-height; interradial ones shorter. Tentacle-bulbs elongate, but narrow and conical. There are 8 adradial clubs upon the bell-margin. These are longer than the tentacle-bulbs. The gonads are complexly folded and extend over the entire lengths ot the 4 radial-canals and fuse one with another on the sides of the stomach. Gonads orange- yellow, other parts colorless. Sydney Harbor, New South Wales, Australia, in September. A more detailed description is required before we can be certain of the actual affinities of this medusa, which appears to have been described from immature specimens ? Laodicea? chapmani Giinther. Laoilicrn rhafimani, GiiNTHEK, 1903, Ann. anil Mag. Nat. Hist., ser. 7, vol. 11, p. 425, plate 9, figs. 1-3. North Atlantic, ofl tin- Irish coast. I./i'niire (?) chapmani, MAAS, 1905, Craspedoten Medusen der Sibu^n Expedition, Monog. to, p. 25. — BROWNF, 1907, Annals and Mir. N'at. Hist., ser. 7, vol. 20, p. 469. Bell 17 mm. wide, 12 mm. high. 32 tentacles, only 4 of which have ocelli. These 4 are at the bases of the 4 radial-canals. Marginal clubs ( ?) Cirri ( t) 4 fimbriated, protrusive gonads on restricted parts of the 4 radial-canals somewhat nearer to the sides of the stomach than to the bell-margin. A single specimen taken between 1,070 fathoms and the surface off the Irish coast in N. lat. 52° 18', W. long. 15° 54'. The gonads do not touch the sides of the stomach. Is this an abnormal specimen of L. cruciata or does it belong to some genus other than Laodicea? PLATE 24. Fig. I. Orfhistoma tentaculata, young medusa. Agassiz Laboratory, New- port, Rhode Island, August 18, 1896. Fig. 2. Mclifcrtissa clavigera Haeckel, Tortugas, Florida, June 2, 1906. Fig. 3. Mcliccrtissa clavigera Haeckel. One of the marginal sense-clubs of the medusa shown in figure 2. Fig. 4. LnnJiffa cruciata var. ulothrtx. Part of the bell-margin of the medusa shown in figure 2, plate 23. Fig. 5. Mfliccrtuin campanula, halt-grown medusa with the 4 secondary radial-canals beginning to develop. Nahant, Massachusetts, May 6, 1897. Drawn from life, bv the author. PLATE 24 \ M , LEPTOMEDU8.*:— MELICERT1 M. L'OT Genus MELICERTUM Oken i sensu Ehrenberg and Agassizi. Mrliirria, preoccupied by SCHKANK, 1805, for Rotifers.— OKEN, 1815, Lehrbuch dor Naturgesch., Bd. i, Register p. 4. |'. 1:5. PKRON rt Lt si' n'R, 1809, Ann. du Mus. Hist. Nat. Paris, tome 14, p. 352. — LESSON, 1843, Hist.Zooph. Acal., p. 324. Mflirerlum, OKF.N, 1835, Allgemeinc Naturgesch. fiir alle Stande, Bd. 5, p. 216. — ESCHSCHOLTZ, 1829, Syst. der Acalephrn, p. 105.— EHRF.NBERG, 1837, Abhandl. Akad., 1835, Berlin, p. 255. — AGASSIZ, L., 1862, Cont. Nat. Hist. I'. S., vol. 4, pp. 349, 352. — AGASSIZ, A., 1862, Proc. Boston Soc. Nat. Hist., vol. 9, p. 96; 1865, North Ainer. Acal.. p. 130. — MAAS, 1897, Mem. Mus. Comp. Zool. at Harvard College, vol. 23, p. 19.-- I.I\KO, 1904,200]. Anzeigcr, Bd. 28, p. j|8. CampiineUa, Mourn, 1857, Beskriv af Gronland, p. 95. Melicertella -t- Melirertum, HAF.CKEL, 1879, Syst. der Medusen, pp. 134. 136. Meliccrtidititn, BROWNK, 1901;, Proc. Royal Soc. Edinburgh, vol. 25, p. 764. The name Melicerta appears, inadequately defined, in Oken's Lehrbuch, 1X15, on page iv ot the index and page 125 ot the text. The same medusa is apparently described by Oken. 1X35, under the name ot Melicertum campanula from Greenland. In Oken's Melicertum there are but 4 radial-canalsf ?) and the stomach is tubular and quadratic in cross-section with 4 short lips. The marginal tentacles are of unequal length. It seems impossible to determine whether the medusa described by Oken is or is not the young ot the M. campanula of Agassi/,. The name "Melicerta" is preoccupied, and "Melicertum" would have been hopelessly lost through inadequate definition had it not been clearly defined by A. and L. Agassiz, 1862, 1865. (JKNERIC CHARACTERS. Thaumantiadae with 8 gonads upon the 8 radial-canals. 8 or more tentacles. Without marginal sense-clubs or cirri. With or without a gastric peduncle. The hydroid is .I/,/;, ,-rtnm. Melicertum as here defined is equivalent to M clici-ituni \ Mrli, , -it, II, i of Haeckel, Hartlaub, 1894, and Browne, 11)05, have discovered that Oicniim 'n In, >n tutu Sars, 1835, lacks marginal cirri and has all of the characters of Agassi/.'s Mrlicfrtum. Haeckel labored under the false impression that this medusa had marginal clubs and he therefore established his new genus "MelicertiJium" especially for this species. Browne would therefore amend M elicertidium and define it in the sense of the older genus Melicertum, doing away with Melt- cerium. Bur it appears that Ehrenberg, 1837, placed Sars's species in the genus M<-ln<-rtu>n, and I think it should remain there and be considered a cotype of that genus. Melicertum campanula Oken(?i, Agassiz. Plate 23, figs. 4, 5; plate 24 fig. 5. (?)Mrliccrtum ramfanula, OKEN, 1835, Allgemeinr Naturg. fiir Alle Stande, Bd. c, p. 226. Mrliccrlum campanula, AGASSIZ, L., 1862, Cont. Nat. Hist. I'. S., vol. 4, pp. 349, 352 AI.ASM/,, A., |S(>;, I'm. . Huston Sen Nat. Hist., vol. 9, p. 96, figs. 1 8, 19; 1865, North Amer. Aca!., p. 130, figs. 202-214.— HAM KM., 1879, Svst. drr Mr, I p. 137. — Nt TTINI., 1901, Bull. U. S. Fish Commission for 1899, p. 382, fig. 104.— HARI.IT r 1904. Bull. I . S. Bureau of 1'isherirs, vol. 24, p. 44. — I.INKO, 1904, Zool. An/eiger, Bd. 28, p. 2|8. Mftitertidium {(ittipaiiula, BROWNK, 1905, Proc. Royal Soc. Edinburgh, vol. 2s", p. 766. Adult infiiusa (plate 23, fig. 5). — Bell pyntorm in outline and about 25 mm. in height and 25 mm. in diameter. The gelatinous substance is quite thick, especially at the aboral pole. There are about 70 long, flexible tentacles with hollow, conical, basal bulbs. The tentacles arise from the hell-margin and are all longer than the bell-height. There are no marginal cirri or lithocysts between the tentacles, nor any ocelli. The velum is well-developed. There are 8 simple, straight, quite broad radial tubes. The manubnum is wide and shallow and does not extend quite half the distance from the inner apex ot the bell-cavity to the velar open- ing. There are 8 simple, recurved lips. The 8 gonads occupy the entire lengths of the S radial-canals. These are longer than the canals upon which they lie and are reflected from one side to the other of the radial-canals in sinusoidal curves. The entoderm of the manubiium, gonads, and tentacle-bulbs is ocher-yellow, and the bell often displays a taint yellow tinge. H \drold and \ouno medusa. — The eggs are cast into the water and develop into pear- shaped planulae. The planulae are ciliated and swim about near the bottom of the aquarium. They soon attach themselves by the blunt (foremost) end. and the narrow ((undermost) end then develops into a long, narrow trunk, which becomes the mam stem of the hydroid. The distal extremity of the stem expands and forms the first polvpite. The polypites are long. cylindrical, and protected by a small, funnel-shaped hydrotheca at their proximal ends. 20S MKIK'S-K OF THE WORLD. There is a circlet of 10 to 12 short, stout tentacles, the bases of which are connected by a web. At the end of six months the hydroid colonies were about 8 mm. in height. In the youngest medusa observed the bell is about twice as high as broad and the bell- walls are thin and flexible. There are 2 well-developed, diametrically opposite tentacles and 2 small, undeveloped tentacle-bulbs. There are 4 straight, radial tubes. The manubrium is very small and there are 4 simple lips. When the medusa is 1.5 mm. in diameter (plate 23, fig. 4) the bell has become relatively flatter and broader. There are now 8 tentacles, 4 long radial and 4 short interradial ones. There are, as yet, but 4 radial tubes and 4 lips. The bell-walls are still thin. When the medusa is about 4 mm. in diameter (plate 24, fig. 5), the bell has become pvriform in shape and the gelatinous substance has greatly increased in thickness. There are }2 tentacles in several stages of development. There are 8 radial-tubes, 4 of which are broad, and 4 very narrow and almost thread-like. The 4 thread-like tubes are new and arise from the periphery of the stomach and extend down toward the circular vessel. The manu- brium is shallow and there are 8 simple lips. The gonads begin at this stage upon the 4 broad radial-canals. The other 4 radial-canals acquire them later. The gonads first appear near the periphery of the stomach and extend down the radial-canals until they reach the circular tube. This medusa is common on the New England coast, north of Cape Cod, during May and early ] une. It has not been taken south of Cape Cod. It is exceedingly abundant on the sur- face in Salem Harbor, Massachusetts, early in the summer, but disappears about the middle of July. The medusa is very constant to its type, individuals having more or less than 8 radial-canals being exceedingly rare. Lmko finds it to be rare off the Murman coast, Northern Russia, near Norway. Mehcertum oi'torostntiint ( = 0ceania octocostnta Sars) of the northern Atlantic coasts of Europe is closely allied to, if not identical with, our American medusa. Melicertum octocostatum Haeckel. Oimntti tjilfjcottatti, SARS, 1831;, Beskriv og Jagttag, p. 24, plate 4, fig. 9 «-ntm campanulalum, EHRENBERG, 1837, Abhandl. d. k. Akad. Wissen. zu Berlin (1835), pp. 190, 255, taf. 8, fign. 5-7- Thaumantias mtlltri, LANDSBOROUGH, 1847, Arran, a poem, p. 265. Stomobrachium octocostatum, FORBES, 1848, British Naked-eyed Medusae, p. 30, plate 4, fig. I . — ROMANES, 1876, Journal Linnean SMC. London, vol. 12, p. 526. Mclicfrtum octocostalurri, Mcltctrtidium oclofottatutn, HAK.CIO.L, 1879, Syst. der Medusen, p. 138. Mi-la frlnlium octocostatum, HARTLAUB, 1894, Wissen. Meeresuntersuch. Kornm. Meere Kiel, Helgoland, Neue Folge, Bd. i, p. 192. — BROWNE, 1905 Proc. Roy. Soc. Edinburgh, vol. 25, p. 762. — BEDOT, 1905, Revue Suisse de Zool., tome 13, p. 138 (literature 1835-50). Bell somewhat conical to pyntorm, with thick, solid apex and thinner sides. About I I to 13 mm. high and 10 to 1 1 mm. wide. There are about 64 large, alternating with 64 small, tentacles having laterally compressed basal bulbs and no ocelli. No clubs or cirri. Velum narrow. There are 3 to 5 fine, longitudinal lines of nematocyst ( :) cells upon the subumbrella, extending from stomach to margin between each successive pair of radial-canals. These lines occasionally branch or anastomose. In large medusae these lines are usually confined to parts near the margin, extending upward for a short distance only. Such lines have never been observed in the American M. campanula. The stomach is octagonal, prismatic, one-fourth as long as the depth of the bell-cavity. It has 8 slightly crinkled lips. A short, broad peduncle is sometimes present. The 8 radial- canals are broad and straight, and the sinuous linear gonads extend along their outer two- thirds, reaching the bell-margin. Color of gonads, stomach, and basal bulbs of large tentacles, yellow to yellowish-brown. Found ofF the northern Atlantic coasts of Europe, Norway, Helgoland, Scotland. The best modern descriptions are given by Browne and Hartlaub. This medusa appears to differ from the American M . campanula Agassiz in having fine radiating lines of nematocysts over its subumbrella. The gonads appear to be more re- stricted in their position upon the radial-canals, and the tentacles to be more markedly of two sr/.es in the European form. Nevertheless the two "species" are evidently closely related and may eventually prove to be identical. This is rendered probable on account of the Arctic range of M . anufiuuula Agassiz. LKPTOMEDUS.fi — MF.LICKiriVM, M K LICKHTISS \. •_>()() Melicertum georgicum A. Agassiz. Melicertum georgif urn, \CASSIZ, A.., in I,. Agassiz's, 1862, Cont. Nat. Hist. U. S., vol. 4, p. 349; 1865, North American Ac.il, p. 135, figs. 115, 216.— HAECKEL, 1879, Syst. der Medusen, p. 137. Bell pointed above; 20 mm. high, 20 mm. wide. About 30 to 40 tentacles with large basal bulbs. No peduncle. Stomach wide, flat, and octagonal. Mouth long, with 4 ( ' r) lips. 8 gonads covering nearly the entire lengths of the 8 radial-canals, but not touching the ring- canal. Manubrium, gonads, and tentacle-bulbs yellow. Pacific coast of North America, State of Washington, in July. Distinguished by its small number of tentacles and 4 ( ?) lips. Is it identical with M. campanula Agassiz ? Melicertum panocto. Mtlicertflla panocto, HAECKEL, 1879, Syst. der Medusen, p. 135. Bell is high, rounded, nearly barrel-shaped, 10 mm. high, 8 mm. wide. No marginal clubs or cirri. 8 tentacles longer than bell-diameter, with very large, globular basal bulbs. A black ocellus on each tentacle-bulb. The ocellus is flanked by a half-moon-shaped black spot on both sides. Stomach octagonal, prismatic, half as long as bell-height. 8 long, much folded, crinkled lips. 8 spindle-shaped gonads developed upon entire lengths of 8 radial- canals. Color ( ?) Azores, Atlantic. Described by Haeckel from a preserved specimen. May it not be a specimen of .\f,li- certissa clavigera which has lost its marginal clubs ? Melicertum (?) Aglantha (?) proboscifer Maas. Mcliccrtum proboscifer, MAAS, 1897, Mem. Mus. Comp. Zool. at Harvard College, vol. 13, p. 19, taf. z, fign. 5-7. Bell rounded, 40 mm. wide, 15 mm. high; bell-walls quite thin. No apical projection. About 1 60 or more short, slender, tapering tentacles, nearly all of which were broken off short in the specimen studied by Maas. No lithocysts observed. Velum weaklv developed. 8 straight, narrow radial-canals and a simple, marginal ring-canal. Stomach small, urn- shaped, and mounted upon a narrow, long, cylindrical peduncle as long as depth of bell- cavity so that the stomach projects beyond velar opening. There are 8 short, recurved, somewhat folded lips. 8 sausage-shaped gonads arise from middle of subumbrella lengths of the 8 radial-canals and project outward into bell-cavity. Entodermal parts, including interstitial lamella of bell, intense carmine; tentacles rose-colored. Found in the Gulf of Panama, Pacific coast of Central America, in March, 1891, by the Albatross. I believe that future studies will show that this medusa is one of the Aglauridae, possi- bly Aglantha. Its slender (solid ?), brittle tentacles, 8 sausage-shaped gonads, and lon<;, cylindrical peduncle are all characters of Aglant/ia. The lithocysts of Aglauridae are often dif- ficult to observe owing to their being readily lost, even in living medusae, and in preserved specimens they are rarely detected. All known species of A yluntha have 4 lips, but this medusa is said to have 8; however, its general appearance is wholly unlike that of any other Meli- certum, but closely resembles that of the known species of Aglantlia. Genus MELICERTISSA Haeckel, 1879, sens, emend. \lelicertissa+ Melicrrlitlium, HAECKEL, 1879, Syst. tier MeJusen, pp. 124, i;c, 137. Mflicerltjiurn, MAAS, 1905, CraspcdotrM MrdiiM-n der Siboga Expedition, Monog. lo, p. IJ. Melicertiisa, BROWNF, 1907, Annals and Mag. Nat. Hist., ser. 7, vol. zo, p. 476. CKNKRIC CHARACTKRS. Thaumantiadae with S simple radial-canals upon which the 8 gonads are developed. 8 lips and 8 or more marginal tentacles. Marginal sense-clubs or cirri, or both, are present. Development unknown. '7 210 MEDUS.fi OF THE WORLD. Our Melicertissa is equivalent to Melicertissa -\-Melicertidium of Haeckel, 1879. Haeckel would restrict Melicertissa to include medusae with only 8 tentacles, while Melicertidium would apply to medusx with more than 8 tentacles. It is probable that Melicertissa as defined by Haeckel is only the young of his Mi-liiertiJiiim. His name Melicertissa precedes that of Mel i- certiJiuin and should therefore designate the genus. Melicertissa is closely related to Melici-rttitn, but is distinguished by its rudimentary mar- ginal sense-clubs or cirri which are absent in Melicertutn. Melicertissa clavigera Haeckel. Plate 24, figs. 2 and 3. Melictriiisa clavigera, HAECKEL, 1879, Syst. der Medusen, p. 135, taf. 8, figs. 8-12. ( ?) Melicertella panoclo, HAECKEL, Ibid. p. 135 (a damaged specimen without marginal clubs?). Bell 7 mm. in diameter, flatter than a hemisphere, with moderately thin walls becoming thinner toward margin. 16 marginal tentacles with long, hollow, tapering basal bulbs and coiled lash-like ends. When contracted these tentacles are each about half as long as the bell- diameter. 8 of the tentacles are radial and 8 interradial. There are 16 sense-clubs (plate 24, fig. 3) midway between the tentacles. There is a well-developed, black, entodermal, cup-like mass of pigment at the base of each tentacle and sense-club, 32 in all. In some specimens one or more of the interradial tentacles are replaced by a marginal sense-club. Haeckel, indeed, describes only 8 radial tentacles and 24 marginal sense-clubs, there being no interradial ten- tacles. His specimens were obtained in the Canary Islands. At Tortugas, Florida, however, we find specimens with interradial tentacles, but which conform in all other respects toHaeckel's medusa. 106. FIG. 106. — Melicertissa clavigera, after Haeckel, 1879. FII;. 107. — Melicertissa malayica, after Maas, in Hydromedusen Siboga Expedition. Velum well developed. There are 8 straight, narrow radial-canals and a simple, circular vessel. Stomach about one-fourth as wide as bell-diameter and the 8 radial-canals arise singly from its periphery 45° apart. Stomach flat and entire manubrium short and not over one- third as long as depth of bell-cavity. There are 8 short, simple lips. The gonads are linear, somewhat sinuous, and occupy the middle halves of the radial-canals, not touching the cir- cular canal or edge of stomach. Entoderm of stomach, radial and circular canals, and tentacle-bulbs dull yellow in speci- mens from Tortugas, Florida ; the entodermal marginal ocelli black. Haeckel describes the color of the entoderm in the Canary Island specimens as being bronze-colored, brownish, or greenish-yellow. Haeckel found this medusa at Lanzerote, Canary Islands, in January, 1867. We found it on the surface at Tortugas, Florida, early in June, 1906. The American specimens are interesting, for they show that there is no natural distinc- tion between the genera Melicertissa and Melicertidium of Haeckel. Parts of the bell-rim are LEPTOMEDUS.E— MKLICEUTISSA, ORfHISTOMA. 211 usually in the " Melicertissa" condition with only 2 tentacles and 3 sense-clubs in each octant, while other parts of the rim of the same medusa are in the " Melicertidium " condition with 3 tentacles and 2 sense-clubs in each octant. Melicertissa malayica Browne. Melicertidium malayicum, MAAS, 1905, Craspedoten Medusen der Siboga Expedition, Monog. 10, p. 28, taf. 5, fign. 19-31. Melicertissa malayicat BROWNE, 1907, Annals and Mag. Nat. Hist., scr. 7, vol. 20, p. 477. Bell flat, 32 mm. wide, 20 short tentacles in each octant, 160 in all. These tentacles are only about one-tenth as long as the bell-radius and their outer ends are coiled. They have slightly swollen basal bulbs. At the base of about every fourth tentacle there is an abaxial, ectodermal, swollen ocellus. Altogether there are 40 to 48 of these ocelli. A number of small clubs arise from the margin between the tentacles. These are about hall as numerous as the tentacles and are irregularly scattered around the margin. The cores of these clubs are filled with entodermal cells, as in LaoJicea. A few small, coiled cirri, much fewer than the clubs, arise from the margin, each containing an axial core of entoderm. Velum narrow. There are 8 straight, narrow radial-canals and a simple, slender ring- canal. Stomach flat, without a peduncle and with 8 simple, folded lips. Gonads linear and developed upon the sides of the proximal thirds of the 8 radial-canals, adjacent to stomach. The gonads begin to develop when the medusa is 18 mm. wide. The ocelli at the bases of the tentacles are black. (See figure 107, page 210.) Malay Archipelago, Ternate. 2 specimens found by the Siboga expedition. Genus ORCHISTOMA Haeckel, 1879. Orchisioma, HAECKKL, 1879, Syst. der Medusen, p. 138.— KELLER, 1884, Recueil Zool. Suissc, tome I, pp. 417, 418. The type species of this genus is Orchistorna pileus, described by Lesson (1845, p. 317, plate 6, fig. i) under the name of Mesonema piletis. This species is believed to have come from the west coast of Africa. GENERIC CHARACTERS. Thaumantiadz with more than 8 simple radial-canals which arise separately from periph- ery of stomach. The gonads are situated upon the radial-canals. Numerous tentacles. Cirri or marginal sense-clubs may or may not be present. Mesonema of Eschscholtz, 1829, is one of the yEquoridae, and hence this generic name can not be applied to the type species of Orchistorna. Orchistoma pileus Lesson. Plate 25, figs, l to 4. Mesonema pileus, LESSON, 1843, Hist. Zooph. Acal., p. 317, planchr 6, fig. i. Orchisioma steenstrupii, HAEI KEL, 1879, Syst. der Medusen, p. 139, taf. 15, fign. 3-5.— KELLER, 1884, Recueil Zool. Suisse, tome I, p. 417. Bell flat-topped with vertical sides, 30 to 40 mm. in diameter. Gelatinous substance thick. 64 short tentacles with well-developed, hollow, basal bulbs; these tentacles are shorter than the bell-radius and are flat and ribbon-like, with hollow bulbs. About 100 small, solid, straight cirri from the side of exumbrella at a short distance above the bell-margin (plate 25, fig. 2). The entodermal cores of these cirri are connected with the entoderm of tin- circular canal. There are about 400 dark-brown, entodermal ocelli upon the circular canal. Each ocellus is provided with an ectodermal lens (plate 25, fig. 3). Velum narrow. There are 32 straight, narrow radial-canals. The manubrium is pro- vided with a large peduncle fully half as wide as bell-diameter and not quite as long as wide; it extends a short distance beyond the velar opening. The stomach is wide and shallow, and there are 32 long, complexly crenated lips (plate 25, fig. 4). There are 32 short, swollen, linear gonads, one upon each radial-canal very near its point of juncture with the stomach. In the female the gonads are cinnamon-color, lips sage-green, tentacles ocher-yellow, and ocelli black. Other parts colorless. In the male, however, gonads, lips, and tentacle-bulbs are dull blue-gray. 212 MEDUS.E OF THE WORLD. Lesson first found this medusa off the west coast of Africa ( ?). Haeckel describes it from the West Indies, and I have taken it upon the surface of the Gulf Stream off the Bahamas and near Tortugas, Florida, from March to July. The males greatly outnumber the females. Distinguished from O. agariciforme Keller, from the Mediterranean, by having 32 lips instead of only 7, as in O. agariciforme. Usually very rare, but abundant during the spring and summer of 1907, at Tortugas, Florida. Orchistoma agariciforme Keller. Orchistoma agariciforme, KELLER, 1884, Recueil Zool. Suisse, tome I, p. 418, taf. zi, fign. 1-3. Found by Keller at Naples, Italy. Similar to Orchistoma pileus in all respects except that there are but 7 lips instead of 32, as in the Atlantic species. The color is not described by Keller, who found only one mature and one young specimen. Like the Atlantic form, it is very rare. 19 or more (about 32 ?) radial-canals. Keller states that the gonads are diverticula from the stomach which extend outward along the radial-canals. Orchistoma tentaculata Mayer. Plate 24. fig. i. Orchntoma tentaculata, MAYER, 1900, Bull. Mus. Comp.Zool. at Harvard College, vol. 37, p. 8, plate 5, fig. 19. — NUTTING, 1901 , Bull. U. S. Fish Com. for 1899, p. 377, fig. 92. — HARGITT, 1904, Bull. U. S. Bureau of Fisheries, vol. 24, p. 44, I fig. Youn% medusa. — Bell 6 mm. in height. Sides near margin slightly flanged outward. Gelatinous substance of upper part of bell very thick, so that concavity is shallow. 32 mar- ginal tentacles in various stages of development, the longest being about 1.5 times as long as bell-height. Tentacles with long, hollow basal bulbs. No marginal sense-organs. 16 functional radial tubes and 16 others in process of development. Radial tubes straight with no traces of gonads upon them. Velum well developed. Manubrium flat and shallow, 8 lips. The entoderm of the basal bulbs of the tentacles delicate green. Only one immature specimen of this medusa has ever been seen; no gonads were visible. It was found on the surface at Newport, Rhode Island, August 18, 1896. Nutting states that the tentacle-bulbs are red. They are certainly green by reflected light, but probably red by transmitted light. Descriptions of color in this work are based upon the appearance presented by reflected light. Professor Nutting's figure and mine are drawn independently from the same specimen while yet alive. The differences between this medusa and 0. pileus are so considerable that it does not seem possible that the one can be the young of the other. Genus TIMOIDES Bigelow, 1904. Timoides, BIGELOW, 1904, Bull. Mus. Comp. Zool. at Harvard College, vol. 39, p. 254. The only known species is Timoides agassizn Bigelow, of the Maldive Islands, Indian Ocean. GENERIC CHARACTERS. Thaumantiad.-c with 4 radial-canals and a ring-canal which gives rise to blindly ending, centripetal canals. Stomach mounted upon a peduncle. Tentacles numerous, without lateral cirri. Numerous cirri upon bell-margin. There are no lithocysts. 4 gonads on the 4 radial- canals. Dr. Bigelow, upon re-examining his 'specimens, tells me that the medusa has no lithocysts. Timoides agassizii Bigelow. TimoiJes agassizii, BIGELOW, 1904, Bull. Mus. Comp. Zool. at Harvard College, vol. 39, p. 254, plate 3, figs. 10, n. Medusa bell-shaped with rounded dome and flaring sides; 20 mm. wide, 14 mm. high, with very thick gelatinous substance at apex, but thin at margin. 32 tentacles, 4 radial, 4 interradial, 8 adradial, and 16 intermediate. The 4 radial tentacles are at the ends of the 4 radial-canals. The 4 interradial and 8 adradial tentacles are at the bases of the 12 interradial LKI'TOMKIH'S.K TlMnlDKS, STAl KODIsrlS. 21:5 and adradial centripetal canals which arise from the ring-canal and end Mindly in the gelat- inous substance of the bell. The remaining 16 tentacles alternate with the radial and centripetal canals. All of these tentacles are exceedingly flexible and contractile; when contracted they are usually coiled helically, this coiling being more or less local and usually not affecting the entire length of the tentacle. When expanded, the tentacles are about 300 mm. long. In addition to the tentacles there are numerous cirri along the bell-margin, but no cirri arise from the sides of the tentacle-bulbs. No lithocysts upon the bell-margin. The 4 radial-canals are straight and slender. There is a marginal ring-canal which gives off 12 blindly ending, centripetal vessels, the 4 interradial ones being about two-thirds as long as the bell-height, and the 8 adradial ones are only half this length. Velum well developed. Peduncle nearly cylindrical, flaring at its base, and twice as long as depth of bell-cavity. The barrel-shaped stomach is almost as long as the peduncle and bears 4 lancet-shaped lips with complexly folded margins. These lips may be longer than the combined lengths of stomach and peduncle. The 4 gonads are upon the lower half of the peduncle on the 4 radial-canals, above the stomach. I hey consist of a great number of simple and branched papilliform processes on both sides of the 4 radial- canals, thus forming 4 prominent, double ridges. The gelatinous substance of the hell is faintlv tinged with blue. The radial-canals and tentacles are rose- pink and there is a pink pigment-spot at base of each tentacle. Stomach and lips pink-\iolet. Gonads rich Indian yellow, changing in some lights to ruddy-orange. I his beautiful medusa was found by Dr. Bigelow in abundance in Haddummati Atoll, Maldive Islands. Indian Ocean, on January 8, 1902. It appears upon the surface at about 4 p. m. Genus STAURODISCUS Haeckel, 1879. Staurodisfus, HAECKEL, 1879, Syst. der Meilusrn, p. 145. — BROWNE, 1907, Annals and Mag. Nat. Hist., SIT. 7, vol. 20, p. 475. \on Staurodixus, AGASSIZ AND MAYJR, 1X99, Bull. Mus. Comp. Zool. at Harvard College, vol. 32, p. 164. Staurodiscua (in part), MAAS, 1904, Sit/unr her . ni.itli.-pli\ > . Kl.issr ki;l. Bayer. Akad. der Wissenschaflcn, Bd. ^4, p. 440. This genus was founded by Haeckel, 1874, for StnurrtJisfU) t.-timtiiurus found at the Canary Islands and off the Honda coast. FK;. 108. — Timoides agassizit, after BIL'''"'A, in Bull. Museum Comp. Zoo], at Harvard College. (.1 NFRIC CHAKACT1 KS. Thaumantiadae with 4 radial-canals, each Diving rise to 2 side branches which end blindly. Tin- uonads are upon the 4 principal radial-canals and their side branches. There may or may not be marginal sense-clubs between the tentacles. Development unknown. Staurodiscus is closely related to Cannot a, but in duniiotn the side branches of the radial- canals fuse with the circular vessel, whereas in Staurodiscus they end blindly. Maas, 1404, considers Staurodiscus to be the young of ('./niiinin. and believes that the side branches of the radial-canals eventually fuse with the ring-canal. I have seen hundreds of medus;e of Staurodiscus ti-tniituurus, evidently mature, but have never found the side branches fused with the ring-canal, ('.unnotn doubtless passes through a "Staurodiscus stage," but on the other hand there appear to be medusae which do not attain to the C.nnnntii condition anil must be called Staurodiscus. "Staurodiscus" mgrifans Agassi/ and Mayer should be called C 214 MEDUSAE OF THE WORLD. nii;ri<:ans. It is probable that Dipleurosorna brooksn is derived from a Staurodiscus ancestor by tbe new formation of 4 interradial canals and the growing outward of the side branches of the perradial canals until they join the ring-canal. Staurodiscus tetrastaurus Haeckel. Plate 22, figs. 7 and 8; plate 25, fig. 5; plate 26, figs. 10 and 11. SlaaroJiscui tetraslaurus, HAECKF.L, 1879, Syst. der Medusen, p. 145, taf. 9, fign. 1-3. — MAYER, 1900, Bull. Mus. Comp. Zool. at Harvard College, vol. 37, p. 46, plates 1 8, 19, figs. 47-49. — MAAS, 1904, Sitzungsber. math . -phys. Klasse kg). Bayer. Akad. der Wissenschaft., Bd. 34, p. 440. — BROWNE, 1907, Annals and Mag. Nat. Hist., ser. 7, vol. 20, p. 475. Ottarrftna gelalinosa (young medusa), MAYER, 1900, Bull. Mus. Comp. Zool. at Harvard College, vol. 37, p. 8, plate 6, figs. 20, 2 1 . Bell 4.5 mm. in diameter, and about twice as wide as high. In adult medusae there are 8 long, flexible tentacles with hollow basal bulbs. Some specimens have 24, others 16 sensory- clubs upon the bell-margin. 32 black entodermal ocelli, one at the base of each tentacle-bulb and sensory-club. Velum is well developed. Only 4 radial-canals reach the circular vessel. From the middle points of each of these canals there arises a pair of equally developed side branches that end blindly. The gonads are upon these side branches and on the distal part of each radial-canal. The manubrium bears 4 prominent lips. Entoderm green or yellow. In the youngest specimen observed, the bell was I mm. in diameter and about as high as broad. There were 4 well-developed tentacles, 4 rudimentary tentacle-bulbs, and 8 marginal clubs. The medusa is common on the surface at Tortugas, Florida, in July and August. Haeckel found this species in the Canary Islands, at Lanzerote. I have seen hundreds of specimens at Tortugas and the side branches of the 4 radial-canals appear never to extend to the circular vessel. Staurodiscus heterosceles Haeckel. Staurodiscus heterosceles, HAF.CKEL, 1879, Syst. der Medusen, p. 146. This medusa resembles S. tetrastaurus Haeckel, excepting that the two side branches from each of the 4 radial-canals do not arise opposite one another from the middle of the radial- canals, but one branch is long and arises from the main canal near the stomach, while the other side branch is short and arises from the main canal beyond the middle point near the bell- margin. The long branches arise constantly from one, and the short branches from the opposite sides of the main radial-canals as one glances around the bell. Bell hemispherical, 6 to 8 mm. wide. There are 8 to 3*, usually 1 6, long tentacles with globular basal bulbs, and 40 to 80 marginal clubs between the tentacles. There is an ocellus at the base of each tentacle-bulb and marginal club. 12 club-shaped gonads, one at the outer end of each of the 4 main radial-canals, and one upon each side branch. Stomach, gonads, and tentacle-bulbs yellowish-brown. Ocelli black. Canary Islands, January, 1867, Haeckel. Development unknown. Genus PTYCHOGENA A. Agassiz, 1865. I'lwhogena, Ar.ASSiz, A., 1865, North Amer. Acal., p. 137. — HAECKEL, 1879, Syst. der Medusen, p. 147; 1881, Report on Deep- sea Medusa?, Challenger Report, Zool., vol. 4, part xn, p. 7. \ r»i Ptychogena, MAAS, 1893, Ergeb. der Plankton Exped., Bd. u. K. c., p. 64. I'lytliogetia, LEVINSEN, 1893, Vid. Meddel. Nat. For. Kjbbenhavn, ser. 5, Bd. 4, p. 145. — LINKO, A., 1904, Zool. Anzeiger, Bd. 28, p. 217. — BROWNE, 1907, Annals and Mag. Nat. Hist. ser. 7, vol. 20, p. 473. — BICELOW, 1909, Mem. Mus. Comp. Zool. at Harvard College, vol. 37, p. 149. — TORREY, 1909, University California Publications, Zool., vol. 6, p. 13. This genus was founded by A. Agassiz, 1865, for Ptychogena lactea, found in Massachu- setts Bay. GENERIC CHARACTERS. Thaumantiadae with 4 radial-canals which in the mature medusa give rise to numerous, short, blindly ending side branches. The gonads are situated upon the radial-canals in the interspaces between the side branches, close to the suhumbrella. The stomach is a wide, Hat pouch and the mouth is a simple cruciform slit. The tentacles have no ocelli, and differ in this respect from those of I. nod icca. PLATE 25. Fig. i .Orchistoma pileus, mature medusa, female. Gult Stream, Tortugas, Florida, July 4, 1906. Fig. 2. Orchistoma pileus. Part of the bell-margin. Fig. 3. Orchistoma pileus. One of the ocelli showing the ectodermal doubly convex lens and the entodermal pigment. Fig. 4. Orchistoma pileus. One of the lips. Fig. 5. StdiirrjJiscus tetrastaurus. Side view of mature male. Tortugas, Florida, August, 1898. Fig. 6. Staurophora mertensii, young medusa. Nahant, Massachusetts, May 7, 1897. Figs. 7 and 8. Dipleurosoma collapsa, young stage in the growth of the medusa. Tortugas, Florida, and Nassau, Bahamas, July, 1902-03. Drawn from life, by the author. PLATE 25 LEPTOMKDUS/E — PTYCIIU< MA \. - 1 ."> Ptychogena lactea A. Agassiz. Ptychogena lac tea, AGASSIZ, A., 1865, North Amor. Acal., p. 137, figs. 220-224; 1888, Bull. Mus. Comp.Zool.at Harvard College, vol. 15, p. 128, fig. 422. — HAECKEI., 1879, Syst JIT Mcdusen, p. 147.— BROWNE, 1907, Annals anJ Mag. N.it. Hi ' .MT. 7, vol. 20, p. 473. Ptychogena fiinnulata, HASCKF.L, 1879, Syst. Jcr Meduscn, p. 148; 1881, Rrport on Dccp-sea Medusa-, Report^ H. M. S. Chal- lenger Zool., vol. 4, part ] 2, p. 7, plate 2, figs. 1 lo 8. — LEVINSEN, 1893, Vid.Meddel. Nat. Fur. Kjcbtnhavn, ser. 5, Bd. 4, p. 145. — GRUNBLRG, 1898, Zoolog. Jahrb., Abth. Syst., Bd. 11, p. 465. Plychogrna finnulata var. intermedia LINKO, 1904, Zool. Anzeiger, Bd. 28, p. 217. Adult medusa. — Bell about 50 to 70 mm. in diameter and 20 to 30 mm. in height. Sides ot bell flange slightly outward. The gelatinous substance is about 10 mm. thick at aboral pole of bell, but diminishes constantly in thickness towards the margin. Substance of" bell trans- parent, but quite rigid. There are more than 300 long, slender, highly contractile tentacles, with hollow, finger-shaped basal bulbs. When expanded these tentacles are about as long as the bell-diameter. Their free extremities often become entangled and this causes the tentacles to droop in graceful festoons from the hell-margin. There are 25 to 200 or more marginal sense-clubs. They arise on the inner (centripetal) side of the tentacle bases near the origin of the velum. These sense-clubs are elongate and pynform, with a narrow basal stalk. They are between a third and a half as long as the basal bulbs of the tentacles. Each sense-club is hollow and connected with the lumen of the circular canal. In some places the sense-clubs are as numerous as the tentacles and often alternate with them in position, but on other parts of the bell-margin they are much less numerous than the tentacles. Velum very wide and thin. The 4 radial-canals are wide near their proximal ends, ad|acent to manubrium, but straight and narrow near the circular vessel. These radial-canals are pin- nated in their proximal halves, adjacent to the stomach. In this region they give rise to about 20 to 30 blindly ending, pinnate side branches, upon which the sjenital organs are situated. The genital organs consist of leal-shaped sacs attached to the side branches of the radial- canals. The free outer edges of these sacs are serrated or split up into a number of finger- shaped points. Thus each genital gland consists of 20 to 30 leaf-shaped sacs or lamellae, all connected with the main axis of the radial-canal. Manubrium wide and shallow. The 4 corners of the fundus of the stomach are prolonged into 4 conical tunnels, whose ends extend to the middle of the genital organs and occupy the proximal halves of the 4 radial-canals. Mouth- opening quadrate and about one-third as wide as bell-diameter. Lips irregularly trilled and extend at the 4 radial corners into 4 short, wavy, oral lobes. 4 narrow, ciliated grooves extend along umbrella wall of the 4 radial-canals and meet at center of stomach on gastral surface of gelatinous umbrella, forming a cross. The gonads and tentacle-bulbs are milk)' in color and the marginal sense-clubs are white. All other parts of the medusa are transparent. This medusa appears to be an Arctic form. It was first found by A. Agassiz swimming at considerable depth in Massachusetts Bay. Since then specimens have been described by Haeckel, under the name of Pt\clws>t-ii!nnulata"= P. laflea, after Haeckel, in "Report. Challenger Expedition, Deep-Sea Medusa. v, velum; w, subumbrella; al, lips; urn, umbrella-margin; £r, stomach cavity; ob, marginal clubs; gs, ciliated perradial cruciform furrow in the aboral wall of the central stomach; en, outer part of one of the radial-canals; ck, distal funnel-like part of one of the radial-canals; j, gonad; u, umbrella; 1, tentacles. — PTYCHOGENA. 217 Linko also considers Ptychogena to be a deep-sea form; as Browne, 1907, and Bigelow, 1909, state, however, we have no trustworthy evidence upon this point and it is not improb- able that the medusa is merely a rare and somewhat variable Arctic species which lives constantly at or near the surface. Ptychogena longigona Maas. Plychogcna longigona, MAAS, 1893, Ergeb. der Plankton Eiped., Bd. 2, K. c., pp. 64, 97, taf. 6, fign. 7-9. Plychogena ( ?) longigona, BROWNE, 1907, Annals and Mag. Nat. Hist., scr. 7, vol. 10, p. 474. Bell 25 mm. wide, flat, with firm gelatinous substance. About 100 tentacles very closely set side by side so that they form an outer row around the margin, on the outer side of which is a row of marginal clubs. Circular canal simple, but the 4 wide radial-canals have numerous, indistinct, unbranched diverticula along their sides, the spaces between the lateral branches of the canals being nearly rilled in by the gonads. Stomach shallow and 4-cornered and about one-fourth as wide as the diameter of the bell. The mouth is a wide cruciform opening with lips turned back as in Ptychogena, so that the water may enter the wide openings of the 4 radial-canals at the corners of the stomach. The gonads cover the entire lengths of the 4 radial-canals and their lateral surfaces give rise to hollow, evaginated, sac-like elevations or papillae, which are neither so complex nor so regularly arranged as in Ptychogena. These papillae occur along either side of each radial- canal, but not in the median line. The mature genital products are in the ectoderm. The grooves of the 4 radial-canals extend along the upper wall of the stomach and meet in the middle. Color ( ?) The species was found by the Plankton expedition in the North Atlantic at a depth of 100 to 200 fathoms, but Maas does not give the exact locality. As he states, it may prove to be only a local variety of Ptychogena pinniilnin (Inctea). It differs from Ptychogena I/itten, however, in the simple side branches upon the radial-canals and in that the gonads extend along the entire length of the sides of the radial-canals, not being restricted to their middle parts as in Ptychogfnu lactea. The hollow elevations upon the gonads are also simple and not so regularly arranged as in P. lactea. Medusae somewhat similar to P. longigona were found by the Plankton expedition near the Cape Verde Islands. Ptychogena? antarctica Browne. Ptychogena antarctica, BROWNE, 1907, Annals and Mag. Nat. Hist., vol 20, ser. 7, p. 474. The basal bulbs of the tentacles are laterally compressed and without ocelli. They resem- ble those of P. lactea. Number of tentacles( ?) Sensory-clubs( ?) The 4 radial-canals have wavy outlines, but no lateral branches. The wavy outlines of the radial-canals correspond with those of the gonads, which are broad, lateral folds extending only part way along the radial- canals. The stomach was lost in the single specimen studied by Browne. The tentacles are red. Size of medusa( ?) Found off Cape Andre, Victoria Land, Antarctic Ocean. Ptychogena erythrogonon Bigelow. Ptychogena erythrogonon, Bir.Et.ow, H. B., 1909, Bull. Mus. Comp.Zool. at Harvard College, vol. 57, p. 150, plates 5, 38, and 39. This medusa is beautifully figured and well described by Bigelow. Bell 38 mm. wide, 25 mm. high with very thick gelatinous substance and shallow bell- cavity. 40 to 60 tentacles about one-fourth as long as bell-diameter and with tapering, conical basal bulbs. There are only a very few cirri between the tentacles and these ter- Fic. 110. — Ptychogena longigona, after Maas, in Ergeb. Plankton Expedition. 218 MEDUSAE OF THE WORLD. ininate in a knob-like cluster of nematocysts. Some of the medusae lack cirri and Bigelow never saw more than 3 upon a single medusa. The cordyli or clubs upon the bell- margin are more numerous than the tentacles. There are no lithocysts and no ocelli. When young the outlines of the 4 broad radial-canals are plain. Later they develop short, simple, lateral diverticula and then the gonads develop in the interspaces of these branches close to the subumbrella as in P. longigona. The manubrium is quadrate basally and its side walls are short and barrel-shaped with a widely open mouth. Basal parts of radial-canals, manubrium, and tentacle bulbs are brilliant opaque brick- red; gonads and outer parts of canal system and tentacles lighter. A pale colored line extends along the central line of each radial-canal forming a cross at the middle of the stomach. The entoderm cells contain red, yellow, and black granules, and the ectoderm cells minute, red granules. This medusa is one of the intermediate fauna found at depths of about 300 fathoms in the Humboldt Current off the coast of Peru. Torrey describes another species of Ptychogena from the California coast. (See appendix.) Genus POLYORCHIS A. Agassiz, 1862. Polyorchis, A. AGASSIZ in L. Agassiz's, 1861, Cent. Nat. Hist. U. S., vol. 4, p. 349; 1865, North Amer. Acal., p. 1 19. — HAECKEL, 1879, Syst. der Medus.n, p. 149. — MURBACH AND SHEARER, 1903, Proc. Zool. Soc. London, vol. 2, p. 174. The type species is Polyorchis penicillata A. Agassiz, from the Pacific coast of the United States. GENERIC CHARACTERS. Thaumantiadae with 4 radial-canals which give rise throughout their lengths to many blindly ending side branches. Marginal ring-canal simple and bell-margin not divided into lobes. Numerous sac-like, sausage-shaped gonads attached to the radial-canals and their side branches. Stomach long, tubular, and with 4 simple lips. Polyorchis penicillata A. Agassiz. ( ?) Medusa campanulata, DE CHAMISSO ET EVSENHARDT, 1820, Nova Acta Phys. Med. Leop. Car., tome I o, p. 359, plate 30, fig. I. Meliccrtum pcniciltatum, ESCHSCHOLTZ, 1829, Syst. der Acalephen, p. 106, taf. 8, fig. 4. Aglaura penicillata, DE BLAINVILLE, 1834, Man. d'Actinologie, p. 283, plate 33, fig. 4. Polyorchis peniciUata, A. AGASSIZ in L. Agassiz's, 1862, Cont. Nat. Hist. U. S., vol. 4, p. 349. — AGASSIZ, A., 1865, North Amer. Acal., p. 119, figs. 179-183. — FEWKES, 1889, Amer. Naturalist, vol. 23, p. 593, figs. 3,4; 1889, Bull. Essex Inst. Salem, vol. 21, No. 7, p. 103, plate 4, figs. 6, 7. — BANCROFT, 1904, Journ. Exper. Zool., Baltimore, vol. i, p. 289, 4 figs, (reac- tions to galvanic currents). — BANCROFT, 1906, University of California Publications, Physio]., vol. 2, p. 43, 4 figs. Polyorchis pinnatus+P. penicillatus, HAECKEL, 1879, Syst. der Medusen, pp. 149, 150, taf. 8, fig. 13. Polyorchis — — , LOEB, 1906, Journ. Biological Chemistry, New York, vol. I, No. 6, p. 427 (physiological), Polyorchh campanulata -+- P. penicillata, BEDOT, 1905, Revue Suisse de Zool., vol. 13, pp. 143, 144 (citation of all papers to l8<;o). Polyorchis — — , LOEB, 1906, Dynamics of Living Matter, Columbia Univ. Biol. Series, No. 8, pp. 87, 91, 141. Polyorchis — — , MACCALLUM, 1907, The Journal of Biol. Chemistry, vol. 2, No. 4, p. 385, New York. Bell about 50 to 60 mm. high, 30 to 40 mm. wide, with a slight, solid, apical projection and almost vertical, slightly bulging sides. Gelatinous substance quite thin. 36 to 40 tentacles arise in a single row from the bell-margin. They are equal each to each and are longer than the bell-height. Their basal bulbs are large, elongate, and spindle-shaped, and have dark-purple pigment. There are no other marginal appendages. Velum narrow. Ring-canal simple and unbranched, but the 4 radial-canals give rise each to 15 to 25 pairs of simple, short, unbranched, blindly ending, lateral diverticula. Stomach prismatic with a very short peduncle, and nearly as long as depth of bell-cavity. There are 4 short lips with sinuously folded mar- gins. A row of 4 to 8 elongate, sac-like, sausage-shaped gonads arises from the sides of each of the 4 radial-canals between the sides of the stomach and the feathered (branched) parts of the canals, there being in all 16 to 32 of these suspended gonads. Stomach, gonads, tentacle-bulbs, and radial-canals reddish-brown to purple. Found on the Pacific coast of California to Washington, and as far westward as the Hawaiian Islands. Fewkes found the medusa abundant in bays along the California coast in March and April. He states that when the medusa has 16 tentacles the 4 radial-canals were merely beginning to exhibit notches along their sides and the gonads were beginning to appear at the 4 corners of the stomach. When mature, the medusa has about 36 tentacles. PLATE 26. Figs, i and 2. LaoJicea? neptuna. Tortugas, Florida, July, 1898. Fig. 3. Laodlceal neptuna. Part of the bell-margin. Fig. 4. Staurophora rnertensii, half-grown medusa. Nahant, Massachu- setts. Fig. 5. Staurophora mertensii. Part of the bell-margin of the medusa shown in figure 4. Fig. 6. Staurophora mertensii, mature medusa, natural size. Agassiz Laboratory, Newport, Rhode Island, June 9, 1895. Fig. 7. Staurophora mertensii. Portion of the bell-margin of the medusa shown in figure 6. Fig. 8. Staurophora mertensii. Aboral view of the mid-region of one of the radial-canals of the medusa shown in figure 6. Fig. 9. Staurophora mertensii. Oral view of the mid-region of one of the radial-canals of the medusa drawn in figure 6. This shows the curtain-like folds of the gonads. Fig. 10. StauroJiscus tetrastaurus, young medusa. Tortugas, Florida, July, 1898. Fig. ii. StauroJiscus tetrastaurus. Oral view of female. Tortugas, Florida, July, 1898. See page 206 for description of figures I to 3. ^^^1 Drawn from life, by the author. PLATE 26 . cr / 11 'f •/ "\ . . /• v- . . .^ ,fj ' \ • "r ' ' ) LEPTOMEDUS.E — POLYORCHIS, SPIROCODON. 219 Bancroft, 1904-06, carried out an interesting series of observations upon the galvanotropic reactions of the medusa, showing; that the tentacles and manubrium respond definitely to the current, even detached parts ot the tentacles reacting. The maximum response is at the anode side in sea-water, whether acid or alkaline. The tentacles and manubrium turn and point toward the cathode. The tentacles may be caused to contract slowly and irregularly in a con- stant current. They contract when the current is made and relax when it is broken. Loeb, 1906, finds that the magnesium of the sea-water serves to relax the muscles of the bell, stomach, and tentacles of Pol\r>rcliis; and that the remaining salts of sea-water produce a state of contraction, so that it we place the medusa in any solution resembling sea-water, but lacking magnesium, pulsation is impossible and the tentacles and stomach are contracted. If we add magnesium, however, pulsation is resumed, but this effect of magnesium can be inhibited by addition of an equivalent amount of calcium or potassium. The isolated center of the bell will not beat in sea-water or in a sugar solution, but beats commence in these solutions if we add calcium, strontium, or barium chlorides. No beats occur, however, if we add mag- nesium chloride. The isolated center will beat for 3 to 4 hours in any decalci- fying salts, such as oxalates, fluorides, oleates, citrates, etc. Acids cause the center to beat, while alkalies inhibit such beats. The center does not beat until some hours after being placed in NaCl; but then rhythmical pulsations set in and may last 2 or 3 days. But pulsation may be at once produced in NaCl by adding salts which precipitate calcium, such as sodium citrate, tartrate, oroxa- late. A trace of HC1 or CO2 added to NaCl will also cause beats, as will pure solutions of CaCl2, BaG2, or SnCl2. Beats are inhibited more by !Mg than by Ca. We have thus the \ anomaly that contractions occur in an excess or a deficiency of Ca. Maccallum, 1907, finds that solutions of cascara sagrada, rhubarb, aloin,podophyllin,and colocynth produce temporary pulsations in the isolated center of Polyorehis. Polyorchis minuta Murbach and Shearer. Polyorchis minula, MURBACH AND SHEARER, 1903, Proc. Zool. Soc. London, vol. z, p. 174, plate 19, fig. 3; plate 22, fig. i; 1902, Annals and Mag. Nat. Hist., ser. 7, vol. 9, p. 72. Bell 15 mm. high, 12 mm. broad. Truncated, oval, with thick walls; only 9 mm. wide at velar margin. There are 55 or more tentacles. Yellow ocelli on outer sides of tentacle bases on elevations. 4 narrow radial-canals with short, lateral diverticula. Stomach mounted on a long peduncle extending to level of velar opening. 4 crenated lips. Gonads long, finger-shaped, arising from the 4 radial-canals near base of peduncle. Gonads and tentacles pale yellow in preserved specimens, other parts colorless. Found in Puget Sound, British Columbia. Genus SPIROCODON Haeckel, 1880. SfirocoJon, HAF.CKEL, 1880, Syst. dcr Mcdusen, p. 636. Goneomeandrus, KIRKPATRKK, 1903, Annals and Mag. Nat. Hist., scr. 7, vol. 12, p. 616. The type species and only known form is Spirocodon saltatn\ ot the Inland Sea, Japan. This was first described by Tilesius, 1818, as M,-Jus-rnlis?ns at Tortugas, Florida, convince me that the medusae become mature with blindly ending side branches upon the 4 main radial-canals. Cannota dodecantha Haeckel. Cannota dodecantha, HAECKEL, 1879 Syst. der MeJuscn, p. 151. Staurodhcus nigricans, AGASSIZ, A., AND MAYER, 1899, Bull. Mus. Comp. Zool. at Harvard College, vol. 32, p. 164, plate 4, figs. II, ll. — BROWNE, 1907, Annals and Mag. Nat. Hist., vol. 20, ser. 7, p. 475. Bell thin and flexible, 14 mm. in diameter. 12 short tentacles with well-developed basal bulbs. The 4 tentacles at the bases of the 4 main canals are about twice as long as the 8 which arise from the ends of the lateral branches. The longest tentacles are, however, only about one- sixth as long as bell-diameter. Between each successive pair of tentacles there are J small protuberances upon the bell-margin, each one of which bears a sensory-club. Velum narrow. Each of the 4 radial-canals gives rise to a pair of opposed lateral branches and thus 12 canals reach the circular vessel 30° apart. The gonads are developed upon these 12 trident- like terminal canals. Manubnum is \et\ short, mouth-opening wide. Gelatinous substance and entodermal lamella of bell of a brownish tinge. Genital organs, basal bulbs of tentacles, and manubrium are light-sepia in color. Bulbs of sensory-clubs are dark-brown. This medusa was found near Suva Harbor, Fiji Islands, South Pacific, in December, 1897. Haeckel describes a small specimen 4 mm. wide from New Guinea. (See fig. 1 13.) Cur Cuv Cui Cm Cm Genus CUVIERIA Pe"ron, 1807. eria (in botany), KOBREUTER, 1802; DE CANDOLLE, 1807. eria (medusa), PERON, 1807, Voyage aux terres australcs, plate 30, figs. 2, 2a.— AC.ASSIZ, L., 1862, Com. Nat. Hist. V. S., vol. 4, p. 345. eria (echinoderm), PERON, 1817. eria (crustacean), DESMAREST, 1825. eria (mollusk). RANG, 1828. Berenix, PERON ET LESUEUR, 1809, Annal. du Mus. Hist. Nat. Paris, tome 14, p. 327. Berenice, OKEN, 1815, Lehrbuch der Naturgcsch., Teil 3, Zoul., p. 1 14.— ESCHSCHOLTZ, 1829, Svsl. der Acalrphrn, p. 120. — MILNE-EDWARDS, 1849, Cuvier's Regne animal illvistrr. /.ii»|>h.. plate ;',, fig. I, la.— HMC KM . iS-9. Sv-t. .|rr Mrdusen, p. 152. — MAAS, 1904, Sitzungsber. math.-phys. Klasse kgl. Bayer. U-.i.l. \\ i ^ MM h.ifi., B.I. -,4, p. 440. — BF.DOT, 1901, Revue Suisse de Zool., tome 9, p. 482; Ibid., 1905, tome i-,, p. i •, i (list of all references from 1807-1850). As is apparent from the above, the name C.ir, i,-im was first used in botany in 1802, and in zoology for a medusa in 1807. Its previous use in botany does not inuiK-u- \\ith its use in zoology. The type species is Cuvicria carisockroma of Peron from the tropical Atlantic. 18 222 MEDUS.E OF THE WORLD. GENERIC CHARACTERS. Thaumantiadae with 4 principal radial-canals which branch, and the branches again branch, and all unite with the circular vessel. The gonads are developed upon the outermost branches of the radial-canals near the ring-canal. Tentacles numerous. There may or may not be marginal clubs or cirri. Development unknown. Modern authors have commonly followed Peron and Lesueur, 1809, and Eschscholtz, 1829, in calling this genus Berenice, but if we follow the rule of precedence the name Cuviena must stand. It is rarelv a pleasant duty to revive an unfamiliar name to supplant one well known to literature, but happily in this case the name of one whose memory we all delight to honor may once more be associated with a genus in that branch of science which his labors ably advanced. Cuvieria carisochroma P£ron. Cuvieria carisochroma, PERON, 1807, Voyage aux terres australes, plate 30, figs. 2, 2a. ."Equorea euchroma and fequorea rosea, DE LAMARCK, 1817, Anim. sans vertebres, tome 2, p. 497. Berenice rosea, ESCHSCHOLTZ, 1819, Syst. der Acalephen, p. 120. — HAECKEL, 1879, Syst. der Medusen, p. 153. — BEDOT, 1901, Revue Suisse de Zool., tome 9, p. 482; Ibid., 1905, tome 13, p. 131 (list of papers to 1850). (?) Berenice capillata, HAECKEL, 1879. Syst. der Medusen, p. 154, taf. 9, fig. 5. According to Peron, bell is flat and shield- shaped, about 50 mm. wide and 10 mm. high. There are 50 to 60 very long thin tentacles with very large, hemispherical basal bulbs. Each of the 4 principal radial-canals gives rise to two opposed side branches, and these side branches as well as the principal canals give rise to 3 to 5 terminal branches which reach the circular canal. Thus 50 to 60 canals reach the circular vessel. The 50 to 60 gonads are developed on terminal branches of canals. Bell, gonads, and tentacles rose-red, and tentacle-bulbs yellow. This species is found in the tropical Atlantic. I am inclined to regard Haeckel's Berenice capillatij as being identical with this medusa. According to Haeckel the bell in B. " capillala" is hemispherical, 20 mm. wide, 100 to 120 long ten- tacles, with well-developed globular, spindle-shaped basal bulbs. There are no marginal clubs or cirri. The 4 main radial-canals and their 2 side branches each and all give rise to 4 to 8 terminal branches, so that 50 to 100 vessels reach the marginal ring-canal. Small, spindle-shaped gonads are developed upon the terminal branches of the radial-canals near the ring-canal. Stomach small, with 4 simple, recurved lips. Color (?) Cape Verde Islands, Atlantic Ocean. Cuvieria huxleyi. Berenice huxleyi, HAECKEL, 1879, Syst. der Medusen, p. 154, taf. 9, fig. 4. Bell flat, 16 mm. wide, 0.4 mm. high. 16 long tentacles with globular to spindle-shaped basal bulbs with ocelli. 80 to 100 marginal clubs, 2 to 6 between each successive pair of ten- tacles. Stomach small, flat, with 4 simple, short, cruciform lips. The 4 main radial-canals FIG. 114. — Cuvieria "capillnla"= C. carisochroma, after Haeckel, 1879. LKITO.MKDrs.K -< T VIKHIA. DK 'H< )T< iM I \. 223 each give rise at their middle points to 2 opposite side branches. These main canals and their 2 branches each end in 5 to 7 terminal branches, and thus about 70 vessels reach the ring- canal. Gonads spindle-shaped, on terminal branches of the canals near the ring-canal. Color (?) Found off Azores, Atlantic Ocean. Distinguished by its large number of marginal clubs and few tentacles. Is it only a variety of ('111-1,11/1 ciirisochrntnii 1'eron ( ?)• Genus DICHOTOMIA Brooks, 1903. Dichotomia, BROOKS, 1903, Proc. American Philosophical Society, Philadelphia, vol. 42, p. i i . - MA*S, 1904, Siuungsber. math.- phys. Klasse kgl. Bayer. Akad. dcr Wisscnschaften, Bd. 34, Heft 3. CKNKRR CHARACTERS. Berenicidae with 4 main radial-canals which divide dichotomously 2 or more times and open into the circular vessel by 16, 32, or more distal branches. Tentacles of t\\<> suits hollow ones and solid ones — all arising from bell-margin. Mouth simple without prominent lips. The gonad encircles the stomach and extends outward over the radial-canals and their branches. 115. 116. Fie,. 115. — Curifria huxltyi, after Haeckel, 1879. Flc;. lib.— Dichotomia cannoides, after Brooks, in Proc. American Philosoph. Soc., vol. 42. A, young medusa. B, adult medusa. C, model showing arrangement of radial-canals. The type species is Dicliutniniu < annoides, described by Brooks from the Bahama Islands. This is the only known species. Dichotomia cannoides Brooks. Dichotomia cannoides, BROOKS, 1903, Proc. American Philosophical Soc. Philadelphia, vol. 42, No. 172, p. 12, plate i, 3 figs. — MAAS, 1904, Sitzungsbcr. math.-phys. Klasse kgl. Bayer. Akad. der \VisM-nschaft., Bd. 34, p. 438. Bell about 8 mm. high and 6 mm. wide, subcylindrical, and with conical apex. The 4 main radial-canals do not arise independently and directly from aboral end of stomach, but in pairs from the ends of a short transverse canal, so that the only planes which divide the medusa into symmetrical halves are the two primary interradial planes, \\hen thus divided each halt is bilaterally symmetrical, and the halves are reversed copies of each other (fig. i i<' i . The 4 primary radial-canals branch dichotomously at least 3 times, so that 32 terminal branches 224 MKIH'S.K OF THK WORLD. reach the circular vessel. The radial-canals of older medusae may branch more profusely. The subumhrella consists of two strongly contrasted regions: An upper opaque part, nearly hemispherical, contains the arches formed by the gonad, which spans space between proximal pairs of radial-canals and stomach in a system of groined arches. The lower half of the subumhrella is transparent and without these arches. There are 16 long, hollow, contractile tentacles with tightly coiled tips. In the young medusa, with only i" terminal radial-canals, these tentacles arise from margin at base of each canal; but in older medusae, with 32 terminal branches of radial-canals, the hollow tentacles are in the radii of dichotomy. In addition to the long, hollow tentacles, there are a number of short, stiff, solid tentacles, which remind one of the solid tentacles of Geryonidae, and are carried turned upward from bell-margin. These short, stiff tentacles are equal in number to the terminal branches of radial-canals. There are no marginal sense-organs, clubs, or cirri. The manubnum is a truncated cone, extending about two-thirds the distance from inner apex of bell-cavity to margin. The gonads and manubrium in old medusae are opaque white. The radial-canals, cir- cular vessel, and axes of hollow tentacles in young medusae are colored by brownish to orange pigment-granules. The bell, subumbrella, and tentacles are nearly colorless in old medusas. This interesting medusa was found by Professor Brooks at Nassau, Bimini, and Green Turtle Key among the Bahama Islands, and was described by him in detail. Genus DIPLEUROSOMA Axel Boeck, 1866, sens, emend. Difleurosoma, AxFLBoECK, 1866, Forenings Vidensk. Meddelclser, Nos. 10, 1 1, pp. 131,136. — HAECKEL, i879,Syst. der Medusen, pp. 155, 636. — AOASSIZ A. AND MAYER, 1902, Mem. Mas. Comp. Zool. at Harvard College, vol. 26, p. 148. — BROWNE, 1898, Proc. Zool. Soc. London for 1897, p. 826; 1900, Proc. Royal Irish Acad., ser. 3, vol. 5, p. 715. Telracannota, MATER, 1900, Bull. Mus. Comp. Zool. at Harvard College, vol. 37, p. 46; 1904, Mem. Nat. Sci. Brooklyn Inst . Mus., vol. i, p. 12. Tetracannota + Dipleurosoma, MAAS, 1904, Sitzungsber. math.-phys. Klasse kgl. Bayer. Akad. der Wissenschaften, Bd. 34, pp. 440, 441. Ametrangia, ALLMAN, 1873, Nature, vol. 9, p. 73. The type species is Dipleurosoma t \picnm Axel Boeck, 1866, from the coasts of Norway, Newfoundland, and northern Atlantic generally. GENERIC CHARACTERS. Thaumantiadae with 3 or more main radial-canals, some or all of which branch irregularly (not regularly and dichotomously) and connect with the circular vessel. Gonads are upon the radial-canals adjacent to manubrium. Tentacles numerous, and marginal clubs, cirri, and ocelli may be present. The hydroid appears to be CuspiJelln. The radial-canals vary greatly both in number and arrangement in /). t\t>icntn, and are best described by Browne, 1900. This extreme variability has caused the species to he described under various names, fudging from the irregular arrangement in the single specimen of D. pacifica found by Agassiz and Mayer, near Tahiti, the canals may be equally variable. In D. collapsa they appear to be more regular, mature specimens having 16 canals arranged in 4 groups of 4 canals each. Dipleurosoma typicum Axel Boeck. Dipleurosoma typitum, AXEL BOECK, 1866, Forenings Vidensk. Meddelelser, Nos. lo-II, p. 131, fign. 1-3; Ibid., D. stuvitzi, pp. 136, 137, figs. 1-4. — BROWNE, 1900, Proc. Royal Irish Acad., ser. 3, vol. 5, pp. 696, 715, plates 20, 21. — MAAS, 1904, Sitzungsber. math.-phys. Klasse kgl. Baver. Akad. der Wissenschaft., Bd. 34, p. 441. Ameirangia htmhpharica, ALLMAN, 1873, Nature, vol. 9, p. 73. Difleurosoma tyficum+amfliithectum+ irregulare, HAECKEL, 1879, Syst. der Medusen, pp. 155, 636, taf. 9, fig. 9. Dipleurosoma hemisph:rrica,a\DDON, 1885, Proc. Roy. Irish Acad., ser. 2, vol. 4, p. 526. — BROWNE, 1898, Proc. Zool. Soc. London, for 1897, p. 826, figs. 10-12. Bell usually flatter than a hemisphere and about 15 mm. wide. Marginal tentacles very numerous, more than 100. Each tentacle has a bulbous base with an ocellus upon its inner side. There appear to be no marginal clubs in D. tvpicum, but these occur in D. pacifica of the tropical Pacific. Velum well developed. Stomach is flat and watch-glass-shaped, with an irregular outline, and there are 4 lips. In 217 specimens studied bv Browne from Valencia I.I I'l' 'MUM > I! Diri.KI IdisnM v. Harbor, Ireland, the number of radial-canals arising fiom the periphery of tin stomach ranged troni 5 to |H, 43 of the medusae hav ing .y canals. Canals exceedingU irregular in position and in mode of branching, so that it is impossible to define a normal t\pe. but rhe\ appear nor- mally to connect with the circular \essel. The Bounds are developed upon radial-canals adja- cent to the stomach and may be upon all or on onl) a few of the canals. Tin \ van in number from i to 12, and 5 is the most frequent number. The females are in excess of the males in the proportion of about 4 to 3. The ova remain attached to the ovary until the planula sta»e is reached. They were partially reared by the Misses Delap, and developed into hydioids apparently belonging to the genus Cuspidella isee Browne. 1900, p. 696). The gonads, stomach, and tentacle-bulbs are said to be brownish (Haeckel. iS; The changes which the medusa undergoes in its growth are unkno\\n, but Browne be- lieves that the stomach is primarily regular in shape and that it becomes irregularly elongated into lobes by development of the radial-canals. 118. Fu;. 117. — Dipleurosoma ("amphitheetum"'), after H.irckcl, 1879. l'i'.. iiS. -Dipleurosoma pticificti, atlt-r N I . in \lu -rum Cornp. Znol. at Harvard C<>llri;<.. D. tvpii-iuii of the Ninth Atlantic may prove to be identical with /). [>iii'i/ii-a from Tahiti, South Pacific. The only distinctions between the North Atlantic and the tropical Pacific species are their wide geographical separation and the presence of' maiginal clubs in I). piififiin. Dtpleurosoma tvp/fiiiii has been taken ott the northern coasts of Europe and <>rl Newfoundland. Dipleurosoma pacifica Agassiz and Mayer. Diplcurosoma pacifica, Ac, AS si z A., AND MAYI K, 1902. Me in. Muv. Com p. /.""I . at H.n uir^l (.'"II ., \"\ . ;l>. p. i 48, plate j, figs. 13, 14. Bell very flat, about j times as broad as high, 2} mm. in diameter. Surface of exumbrella reticulated by a regular system of hexagonal elevations bounded b\ shallow turn>\\s. About 100 short tentacles with narrow, bulbular bases. Kntodermal core of these tentacles is solid and composed of chordate cells. At the bases of most tentacles upon the lower (subumbrella) side, there is a single black ocellus. Slender, club-shaped, sensory bodies aie scattered at fre- quent and irregular intervals between the tentacles. Entodermal cores of these bodies air solid and very similar to those of the tentacles. No concretions. Velum narrow. <> radial-canals arise in groups of 3 from diametrically opposite sides of the stomach. In the single specimen examined, 2 of these canals bifurcate, and 8 canals thus reach the circular vessel. The <;onads are linear and occupy the middle regions of the S canals. Their surfaces are slighrlv papillate and the ova stand out as hemispherical protuberances. Stomach elongated in the direction of the two opposed groups of radial-canals. Manubrium very short, 6 small, slightly folded lips. Tentacle-bulbs, genital organs, and manubrium milky white, all other parts of the medusa being transparent. A single specimen was obtained in a surface haul about 50 miles ninth of Tahiti. Smith Pacific. 220 MEDUSA OF THE WORLD. Dipleurosoma is exceedingly variable in the number and arrangement of its radial-canals. The Pacific species is distinguished by having marginal clubs between its tentacles, these being absent ( ?) in the Atlantic Dipleurosoma typicnm. Dipleurosoma collapsa Mayer. Plate 27, figs. I to 3, and 7. Tftracannolatolla/>sa,MA\T.tt, 1900, Bull. Mus.Comp.Zool. at Harvard College, vol. 37, p. 46, plates 7,8, figs. 14-16; Memoirs Nat. Sci. Mus. Brooklyn Inst. Arts and Sci., vol. i, No. i, p. 12, plate 4, fig. 32. — MAAS, 1904, Sitzungsber. math.-phys. Klasse lier kgl. Bayer. Akad. Wissenschaft., Bd. 34, p. 440. Adult nii-Jusa (plate 27, fig. 3). — Bell J mm. in diameter and about as high as broad. Tup dome-shaped, side walls vertical. 16 well-developed tentacles are carried tightly coiled in close helices, and besides these there are 1 12 very small rudimentary tentacles. Dark-brown entodermal pigment-spots are found within the base ot each tentacle. There are 16 radial- canals, arranged in 4 groups of 4 each (plate 27, fig. 7). The gonads are found in proximal parts of the 16 radial-canals very near the point where they branch off from the stomach. Peduncle of manubrium wide and prominent. The mouth has 8 slightly crenated lips. Entoderm of manubrium in some specimens is green, in others it is pearly-white or yellowish. Entodermal pigment-spots at bases of tentacles are dark-brown. Stugi-s in development. — The youngest medusa observed had a bell i mm. in diameter (plate 27, fig. i ). It had 4 slender radial-canals and 24 tentacles, 4 well-developed and 20 rudimentary. Velum prominent; 4 lips, and as yet no peduncle. No trace of genital organs. In the next older stage (plate 27, fig. 2), we find 4 new radial-canals beginning to develop. A still older stage (plate 27, fig. 7) has 16 radial-canals and 8 lips, but as yet no peduncle and no trace of gonads, nor have radial tubes grouped themselves into 4 bundles as in the adult. This medusa is very common at the Tortugas and Bahamas in June, and ample oppor- tunity for observing its transformation was afforded. It exhibits the curious habit of collap- sing into an almost shapeless mass, in which condition it may remain tor several hours and then "straighten out" and swim about in excellent condition. Fewkes, 1883 ("On a Few Medusa? from the Bermudas," Bull. Mus. Comp. Zool., vol. ii, No. 3, figs. 7, 70), has evidently figured the young of this species under the name of "Larva of an unknown Tubularian." Dipleurosoma ochracea sp. nov. Plate 29, figs. I and 2. Immature medusa. — Bell thin-walled, somewhat flatter than a hemisphere and 8 mm. in diameter. About 12 to 16 well-developed tentacles and about 35 immature or rudimentary tentacle-bulbs. The well-developed tentacles are in the radii of radial-canals. They have hollow, conical, basal bulbs and filiform, contractile, lash-like shafts, which are about as long as the bell-radius. Each tentacle-bulb is flanked by a pair of large, sausage-shaped, marginal clubs, and in addition to these there is a single sausage-shaped diverticula from the ring-canal on the subumbrella side above each tentacle-bulb. There are no marginal cirri or append- ages other than those described above. Velum very wide. Central stomach is flat and about one-fifth as wide as bell-diameter. About 6 to q radial-canals arise in a very irregular man- ner from margin of stomach; some of these give rise to side branches. Manubrium very shallow, 6 or more very irregularly arranged, folded lips with plain margins. No gonads are observed, though they may develop later upon the broad, expanded middle regions of the radial-canals. Stomach, radial-canals, and marginal clubs of this medusa are crowded with masses of yellow algae, or Philozoon, apparently similar to that which infests the medusae of / elella. These plant-cells develop between the cells of the medusa and give a dense, opaque, brilliant yellow coloration to the marginal clubs, and in a lesser degree to the stomach and canals. All other parts are colorless. The medusae are remarkable for their very active, incessant pulsation. Large swarms of this medusa appeared at Tortugas, Florida, between July 5 and 24, 1907, but no mature specimens could be found. PLATE 27. Fig. I. Dipleurosoma collapsa, young medusa with 4 simple radial-canals. Tortugas, Florida. June, 1897. Fig. 2. Dipleurosoma collapsa, half-grown medusa with 16 simple, separate, radial-canals. Fig. 3. Dipleurosoma collapsa, mature female, with 16 radial-canals grouped into clusters of 4 canals each. Tortugas, Florida, July, 1898. Figs. 4 and 5. N etocertoides brachiatum. Successive stages in the growth of the medusa. Tortugas, Florida; and Nassau, Bahamas, July, 1898 and 1903. Fig. 6. N etocertoides braclnatum. Oral view of medusa shown in figure 4. Fig. 7. Dipleurosoma collapsa. Aboral view of the stomach showing the grouping of the radial-canals into 4 radial clusters ot 4 canals each. Tortugas, Florida. Fig. 8. Turris superba. Aboral view of the stomach showing the inter- radial positions of the gonads. See page 126 for description of figure 8. Drawn from lite, by the author. PLATE 27 — DIPLKUiOSMM \. 227 Dipleurosoma brooksii sp. nov. This form is described from drawings made by the late Prof. William K. Brooks, and found after his death among his unpublished figures. The drawings were generously pre- sented to the author by the Department of Biology of the Johns Hopkins University for reproduction in this work. Bell flatter than a hemisphere, evenly rounded, thin walled. Manubrium small, short, and 8-sided. 8 simple lips, 4 long and 4 short. 8 radial-canals arise from the stomach, the 4 in the radii of the long lips are trident-shaped, each giving rise to 2 side branches. The 4 canals in the radii of the short lips are simple. Thus if> terminal branches reach the circular vessel. In the specimen figured by Professor Brooks only 14 canals joined with Fir,. Il8a. — Dipleurosoma brooksii, sp. nov. A, oral view; n, siilc view with tentacles cut off short; c, oral view of lips. Drawn from life by Professor Brooks. the circular vessel, for two of the side branches of the main radial-canals tailed to develop. There appear to be typically 16 tentacles, one at the base of each terminal branch of the radial-canals, although in two intervals there are small additional tentacles thus giving 18 tentacles in the specimen figured by Professor Brooks. The tentacles have long, conical, tapering basal bulbs, which are hollow and very long, lash-like shafts, longer than the bell- diameter and very flexible. No ocelli are figured by Professor Brooks. The gonads are upon the sides of the 16 radial-canals, not touching the ring-canal but extending from the sides of the stomach outward. The velum is a wide, annular diaphragm. The size and color of the medusa can not be determined from Professor Brooks's drawings. The medusa was found at Nassau, Bahama Islands. 228 OF THE WORLD. Were it not for the absence of ocelli I would be inclined to regard this medusa as a hypertrophic specimen of Staurodiscus tetrastaurus in which the side branches of the 4 primary radial-canals had reached the circular vessel and 4 intermediate canals had developed. I have, however, never observed such a condition among many hundreds of apparently mature medusas of S. tetrastaurus found at Tortugas, Florida ; and it seems probable therefore that Professor Brooks's medusa is a new species which may have been derived from a Staurodiscus-like ancestor. Genus TOXORCHIS Haeckel, 1879, sens. ampl. Toxorchii + Cladocanna, HAECKEL, 1879, Syst. der Medusen, pp. 156, 160. Toxorcliis, MAAS, 1904, Sitzungsber. math.-phys. Klasse kgl. Bayer. Akad. Wissenschaft., Bd. 34, p. 441. Haeckel, 1879, founded this genus for Toxorchis arcuatus of the Canary Islands, Atlantic Ocean; but the first known species is T. thalassina=Berenix tluilnssina Peron and Lesueur, 1809, from Northern Australia. GENERIC CHARACTERS. Thaumantiadae with 4, 6, or more main radial-canals which branch regularly and dichot- omously one or more times. The gonads are upon the outermost branches of the radial-canals, near the ring-canal. Numerous tentacles, cirri, and marginal clubs. Hydroid unknown. Haeckel restricts Toxorchis to include medusae having radial-canals branched once dichotomously, while his Cladocanna applies to medusae having radial-canals with 2 or more dichotomous branchings. Toxorchis thalassina Maas. Berenix lhalassina, PERON ET LESUEUR, 1809, Annal. du Mus. Hist. Nat. Paris, tome 14, p. 327. Berenice euchroma, DE BLAINVILLE, 1834, ManXiel d'Actinologie, p. 276, plate 32, fig. I. Cm'ieria euchroma, LESUEUR, 1839, m Cuvier's Le Regne animal, plate 53, fig. 2. Cladocanna thalassina+ C. pol\clada, HAECKEL, 1879, Syst. der Medusen, pp. 160, 161. Cladocanna polyclaiia, YON LENDENFELD, 1884, Proc. Linnean Soc. N. S. Wales, vol. 9, p. 581. Toxorchis thaiassiria, MAAS, 1904, Sitzungsber. math.-phys. Kla&se kgl. Bayer. Akad. Wissenschaft., Bd. 34, p. 441. Cladocanna thalassina, BEDOT, 1901, Revue Suisse de Zool., tome 9, p. 482; Ibid., 1905, tome 13, p. 132 (list of papers to 1850). Bell flatter than a hemisphere to hemispherical, about 50 mm. wide. About 100 or more long tentacles with marginal clubs and cirri between them. Stomach shallow, with 6 wide lips. 6 wide radial-canals arise from stomach. For one-third the distance between stomach and margin these canals are simple and unbranched, but outwardly they branch dichotomously and somewhat irregularly 3 to 4 times, so that there are about 100 terminal branches which reach the circular canal at the margin. The sac-like, spindle-shaped, folded gonads are developed upon the outermost branches of canals. The entire medusa is light sea-green. Found off the coasts of New Guinea and Northern Australia. Development unknown. Toxorchis arcuatus Haeckel. Toxorchis arcuatus, HAECKEL, 1879, Syst. der Medusen, p. 157, taf. 9, figs. 6-8. Bell flat to hemispherical, 6 mm. wide. Stomach small and flat, with 6 much crinkled, lanceolate lips. 6 main, wide radial-canals which fork at their middle points, so that 12 canals, 30° apart, reach the circular vessel at bell-margin. There are 24 long tentacles with bulbous bases, each bearing a reddish-brown ocellus. Numerous clubs and cirri on bell- margin between the tentacles. The gonads are developed upon the edges of the forked ends of radial-canals, there being iatu*, after Haeckel, 1879. a crescentic gonad upon the concave side of the crotch of each fork, and a pair of linear gonads upon the convex sides of the forks. There are thus 3 gonads upon each main canal at its forking, 18 gonads in all. PLATE 28. Fig. i. Toxorchis kellneri. Side view of female medusa. Tortugas, Florida, July 8, 1907. Fig. 2. Toxorchis kellneri. Oral view of the medusa. Fig. 3. Turris superba (a variety of T. pileata). Tortugas, Florida; July 4, 1907. Mature male medusa. Fig. 4. Turris superba (variety of T. pileata). Side view of manubrium showing the foldings of the interradial gonads. See page 126 for description of figures 3 and 4. Drawn from life, by the author. PLATE 29. Fig. i. Dipleurosoma ochracea. Side view of an immature medusa. Fig. 2. Dipleurosoma ochracea. Oral view of an immature medusa. Fig. 3. Stomotoca pteropliylln. Enlarged view of the medusa, showing the bell contracted so as to reduce the length of the peduncle. Nassau Harbor, Bahamas, April 20, 1907. Fig. 4. Stomotoca pterophylla. Side view of the manubrium of a mature male. Off Miami, Florida, in the Gulf Stream. Fig. 5. Stomotoca pterophylla. View of velum showing radial and circum- ferential muscle-fibers. Drawn from life, by the author. See page 113 for description of figures 3 to 5; page 226 for descrip- tions of figures i and 2. PLATE 29 LEPTOMEDUS.E — TOXORCHIS, NETOCEKTi )1 in >. --".' Stomach, lips, gonads, and tentacle-bulbs are yellowish-brown, speckled with dark-red. Exumhrella besprinkled with reddish-brown spots. Found bv Haeckel at the Canar}- Islands, Atlantic Ocean, in January. 1867. Toxorchis kellneri sp. nov. Plate 28, figs, i an>l j. This medusa is named in honor of the author's assistant, Mr. Carl Kellner. whose copies of figures ot medusae by previous authors appear as text-figures in tins work. Bell about 15 mm. wide, with moderately thin walls, thickest at center ot" bell and thin at edges. When in a normal resting state the bell is somewhat higher than a hemisphere, but when expanded it is slightly Hatter than a hemisphere. There are about $2 tentacles with long, conical, tapering, hollow basal bulbs. The filiform shafts ot these tentacles are highly contractile and normally i to 4. times as long as the bell-diameter, but may be con- tracted so as to become about as short as the bell-radius. There are about 50 small clubs upon the bell-margin between the tentacles; but no coiled cirri nor lithocysts. 1 here is a black entodermal ocellus within ring-canal at base ot" each tentacle and marginal club. Velum well-developed, ring-canal narrow. Stomach about one-fourth as wide as bell- diameter. 8 flat, wide radial-canals arise trom margin ol stomach, 45° apart. A short dis- tance beyond the margin ot the stomach most ot these 8 primary radial-canals bifurcate. Thus in the specimen here fimired n ot the 8 primary radial-canals are bifurcated and thus 14 slender radial-canals reached the marginal ring-canal. The manubrium is shallow, only about one-fourth as long as the depth ot the hell-cavity, and there are 8 lanceolate lips with folded, curtain-like margins. These lips are in the radii of the 8 main radial-canals. The gonads are developed upon the sides of the narrow outer branches of the radial-canals and do not touch the ring-canal. Central stomach pink; gonads and tentacle-bulbs brownish-yellow; entodermal ocelli very dark brown, almost black. Several specimens of this medusa were found in a surface tow at Tortugas. Florida, on July 8, igo/. The figures represent a female. This species differs from Haeckel 's T. uriiintits ot the Canary Islands in its higher bell, more numerous and more irregularly branching radial-canals, in the absence of marginal cirri, and in color. Unfortunately, Haeckel had but one specimen, and I have seen only three, and it is possible that future studies may show that the Canary Island medusa is identical with the Tortugas form. Genus NETOCERTOIDES Mayer, 1900. NcloctrtoiJes, MAYER, 1900, Bull. Mus.Comp. Zool. at Harvard College, vol. 37, p. 45.— MAAS, 1904, Sitzungsber. math.-phys. Klasse kgl. Bayer. Akad. Wissenschaft., Bd. 34, p. 437. GENERIC CHARACTERS. Berenicidae with 8 main radial-canals, which bifurcate so that 16 canals reach the circular vessel at bell-margin. There are 16 long, hollow, tapering tentacles, one at the end of each radial-canal, and 16 to 25 short, cirrus-like tentacles, one or t\\o between each pair ol long tentacles. The manubrium has 4 simple lips. The gonads are developed upon the sides of the manubrium and upon the 8 main stems of the radial-canals. The type species is N. brachiatuiii Mayer, of the Bahamas and Tortugas, Florida. It is the only species of the genus. Netocertoides brachiatum Mayer. Plate 27, figs. 4-6. Nctocertoidei brachialum, MAYF.R, 1900, Bull. Mus. Comp. Zool. at Harvard College, vol. 37, p. 45, figs. 43-44, plate 18; Memoirs Nat. Sci. Museum Brooklyn Institute Arts and Sci., vol. i, p. 12, fig. 7, plate I. Bell 4 to 5 mm. high, miter-shaped, walls quite thin. 10 hollow tapering tentacles; one at base of each of the 16 radial-canals. 1 6 to 25 small tentacles, one or two between each pan of long ones. Longest tentacles about one-fourth as long as bell-height, their ends tightly 230 MEDUS.E OF THE WORLD. coiled. The short tentacles are hardly more than cirri. No marginal sense-organs. Velum well developed. 8 main radial-canals arise from the inanubnum, but each bifurcates, giving in all 16 terminal-canals, which extend straight toward the circular vessel. The 8 proximal roots of the radial-canals are bound to the manubriuin by groined arches. Manubrium broad and disk-like. The mouth is at the extremity of a short neck, surrounded by 4 simple lips. Gonads along the main radial-canals, adjacent to the stomach. Entoderm of tentacles, radial-canals, and manubnum rosin-colored. Quite common at the Bahamas, but rare at the Tortugas, Florida. Seen only in summer. This medusa is closely related to Dichotomic cannoides, but in NctocertoiJfs 8 main radial-canals arise from the stomach instead of 4 as in Dichotomic, and the manner ot branch- ing is quite different, even in young medusae. Monobrachium parasiticum Mereschkowsky. Monabrachium parasiticum, MERESCHKOWSKV, 1877, Annals and Mag. Nat. Hist., ser. 4, vol. zo, p. 220, plates 5, 6. — WAGNER, 1889, Zool. Anzeiger, Jahrg. 12, p. 1 16; 1890, Archiv. Biologic, tome lo, p. 273, plates 8, 9 (details of histology). This interesting hydroid has only I tentacle. Its medusiform gonophore belongs appar- ently to the Thaumantiadae, but the free medusa is unknown, if, indeed, it be set free. The medusiform gonophore is oval and is developed in a sac which arises from the hydrorhiza. The hydroid grows upon the posterior part of the living shell of Tellina calcarea, near the siphon. The hydrorhiza is a flat expansion of anastomosing tubes covered with a thin chitmous membrane. The polypites are about 2 mm. long, tubular, with a single tentacle. This is 4 to 6 mm. long, tapering, lash-like, and arises from the side of the hydranth at a point about one- third the length of the polypite from the mouth. The gonophores are medusiform, about as long as the polypites, and they arise from the hydrorhiza by a short stalk. The contained medusa is oval with a short conical manubriuin, 4 radial-canals, each with 2 gonads upon its sides. Ring-canal and 16 rudimentary tentacles. Color of colony, yellow. White Sea, Russia. K'l'I.X TU Vul.rMK* T AM) II. Adiocheteumena, 430 •/•>'"" 15. 448, -/-/<; Miulrs, 4^4 alternans, /-,'} brunnea, ./f } canarK-nsis, 452 ' '""' ", 45°. 45' 1.1, hscholtzii, 450, ^•,",' lacK-u, 453 pachyderma, 473 r/inJina, 450, ./,-_' IOSI a, 451 .•Ks;im-lhi, 454 bitentaculata, 455 disMiiK-ma, 456 .K"Mi.-ra, 432, 467 o.rona, 437 H.n I-MVMS, 454 gemmifera, 480 glubosa, 476 paiip.-mil.i, 432, 437 rost-a, 480 EginiJ*, 428, 430, ±tf I 'i'i>iiii/is, us, 16, 448, i\n n: tinodiscus, ./.'iVi /Eginodorus, 485 Eginopsis, 15, 44^, 450, 454, hensenii, 455 liiur, ntn, 472, mediterranea, 456 UK itcnsii, 472 />.;,/; \ili-rmn, /~ ,' Eginura, 11^44^^ l"7 gnmalJii, 4^'S, y-o IHilStl, £/2 lanzfrottf, 468, ^dp tn \iisnru, /f'*i \\clu-ri, 470 Equorea, \i, ;j/ , ?;/ ciliata, 325 , .-;';, ,;. ; ;/ cubana, 325 cyanea, 326 iTamigramma, 445 discus, 325 i-iu-liroma, 222 fiiiliiulina, 326 flonjana, Jjo forbcsian.n. ?2^ for sk/il, -a, ;_'•," Volume I extends from paj;r i to 2-0, volume Hi Principal rcfcrt-iurv arc in italics. /Equon •17- globularis, "in nlamlira, maldivensis, ,",'". ^'i Illl S(.|H 111. I, ^^ mina, 12^ M "k .1, 32'', i-V a, ,;,•/, \ppi'inli\, 41/7 , , pl< -1111111.11.1, ^X puiu-tata, 444 pnrpuii-.i, ^S i ii.»!ci|iinia, 4^2, 4^7 risso, 325 nvsoan.i, 32^ rtist .1, • • • st.iui(ii;l\ pi) a, ^^ It-nuts, ;;_' vitrina, , i i. 196, , in \L;.IS-.]/. \l. \.nulc-r, ack i, I ), 2,'I, _','/ . alii nlata, 234 • ' ' / I ••/.iitt/tii, 14, /(>/ conica, 402 tligitiilt1, /"-' Hit, 11111-1/1:1, /"/ -t-in . '/, i itlt-ntnlis, ./a / elongata, /"/ '•it! it;, rn, / •;/n, 362* \nllsi-ta, 4OI I, 404 i !i>iii;ata, 404 405 [i] INDEX. Amalthtea, 5, 22 am&bigera, 22 junuarii, 2J sarsii, 22 uvifera, 22 vardoensis, 23 Ametrangia, 224 hemisphierica, 224 Amphinema, 108 apicatum, 109, 112 nustralis, Appendix, 490, dinema, 109 titania, 109 turrida, Appendix, 490 Amphocodon, 37 ampliipleurus, 39 fritillaria, 39 globosus, 39 gravidum, 39 unicus, 42 Amphogona, 14, 405 apsteini, 4.05 pusilla, Appendix, 497 Anthomeduste, 17 development, 3, 5 Atractylis, 201 Auliscus pulcher, 43 Batliycodon, 73 pyramis, 79 Berenice, 221 capillata, 222 euchroma, 228 huxleyi, 222 Berenix, 221 thalassina, 228 Blackjordia, II, 232, 2j6 manhattensis, 2JJ virginica, 2ff Blastothela, 29 Botrynema, 14, 394- brucei, 395 Bougainvillea mediterranea, 133 paradoxica, 162 ratnosa, 161 Bougainvillia, 2, 3, 8, I$$ allmani, 160 nutiimnalis, l6g bella, 161 benedenii, 161 bntannica, 161 carolmensis, 165 dinema, 164. flaviJa, l6S frondosa, 171 fruticosa, 160, Appendix, 493 fuha, 160, Appendix, 492 gibbsi, 169 glorietta, 172 kollikeri, 179 maclovtana, 160 Bougainvillia maniculata, ijo multicilia, 164 muscus, 155, 161 niobe, 166 nordgaardu, 168 obscura, 172 octopunctata, 177 platygaster, 165 pnncipis, 160 prohjera, Ifo pyramidata, 168 rugosa, If I supercilians, 162 tnnema, IJI xantha, 165 Budding in Medusa;: Hybocodon, 39; Sarsia, 48, 61-64; Margelopsis, 80; Lleutheria, 95; Cytaeis, 133; Bougainvillia, 163, 166, 171; Rathkea, 178, 179, 182, Appendix, 493; Pro- boscydactyln, 191, 192; Phialidium mccradyi, 271; Eucheilota paradoxica, 285; Eirene medusifera, 413; Gonionemus larvae, 345; Limnocnida, 370; Narcomedusae, 429; Pe- gantha, 447; Cunoctantha, 466; Cunina, 478, 481; Rathkea, Appendix, 493. Bythotiara, 8, 185 murrayi, 185 Bythotiaridi, 183 Calcydion formosum, 136 Callitiara, 146 polyoptlialina, 147 Calycopsis, J, /jo, Appendix, 491 typa, 131 Appendix, 491 Calyptra, 376 umbilicata, 378 Campalecium, 291 meJusiferum, 291 Campanella, 207, 449, 454 pachyderma, 473 Campanopsis, 196, 295, 2gS, 302, ^OJ. Campanularia bilabiata, 233 caliculata, 234 compressa, 233 dichotoma, 246 dumosa, 201 flabellata, 249 gelatinosa, 255 geniculata, 244, 246, 249 inconspicua, 266, 269 johnstoni, 262 noliformis, 265 synnga, 269 volubilis, 262 Campanulina, 234, 266, 314, 329 acuminata, 314, 316 hincksii, 284 languida, 269 repens, 235, 317 Cannota, 10, 197, 213, 221 dodicantha. 221 INDKX. Cannotidae, 102, 196 Carmarina, 424 fungiformis, 425 hastata, 425 hexaphylla, 425 Carmaris, 424 giltschii, 425 lj 425 umbella, 425 ( '.n mimothe beroe, 105 Catablema, I2O campanula, 128 i un sronia, 128 vesicanum, 126 Charybdea bitentaculata, 455 ci<;«i<-ii«, 8, 182 centripetalis, 182 Chromatonema rubrum, i , , Cii , 401 camtschatica, 402 elongata, 404 inveitrns, 404 rosea, 402 Cir< ead e, 396 Circi-lla digitalis, 402 Cladocanna, 228 polyclada, 228 rhalassina, 228 Cladonema, 3, 7, 98 perkinsn, IOI radiatum, <)<) Cladonemida, 6, 83 i '.I, i.', it, ll,i, pj prolifera, gq. Clavttln, Appendix, 491 tontata, Appi-ndix, 491 gossei, 122 , ta, Appendix, 491 fi.if'ii.i. Appendix, 401 ( '!,•, .dura tricuspidata, 122 r.l\ti,i, 10, 232, 261 bakori, 262, 495 bicophora, 262 compressa, 233 ri lindrica, 262, 265 eucophora, 236 flavidula, 266 falleata, 264 fragilis, 262 geniculata, 262 johnstoni, 262 polynesiz, 264 rriiit;irnir, 26$ simplex, 262 innvi-rsitatis, 265 i"ilnliilis, 262 Cotionidir, 5, '0 Codonium, 47 apicuhim, 59 conicum, 58 codonophorum, 61 gl niiiiili-rum, 62 I'linccps, 60 Codonorchis, 108 •• 'Irus, 1 1 1 Colobonema, 383 sericeuni, 384, 385 tvpicum, 385 ('.'•nis, 7, /JO iphthalma, 130 initrntii, /JO t'onvt i{;i nrc of: C'tcnaria, t'ra.s|4; Narcomedusac and Lepto- lina nuilii--.!-, 15,84; Mydim rcn.i and C'tui»- plidra-, 4hora, <)8 Ciiliiin, 12, JJO nphrndite, ^^1 Cubogastcr, 132 dissimcmn, 1^4 gemmascens, 133, 178 i-s, 449 primigcnia, 449 [iii] INDEX. Cunantlmhi-, 447 Cunarcha, 449 aeginoides, 454 Cuiiinn, 15, 448, 460, 473 albescens, 482 campanulata, 474- 47 ^ dodeeimlobata, 476 Juplicdta, 475, jSr gl'jbosa, 474, 4~(> kollikiri, 464 liitii'cntns, 474, 476 moncta, 482 mui ilaginosa, 475. -/Xi multifJia, •!'•; nana, 461 parasitica, 4(15 pi nvrinn, 4^ f proboscidea, 474, (.76 prolifera, 474, rliododactyla, 480 solinaris, 482 striata, 449 vitrea, 476 Cunissii, 1 6, 448, j.Sj pnlvplii-rti, />'•," polyporpa, / ^ j i.iiitliu, 15, 448, ./tfo fowlen, 466 incisa, 472 uiirin, 46 r, 404 r.ir. koJllkeri, 464. ftiirnsitifi, 46^ polygona, 465 tenella, 467 Cunoctona, 467 grimaldi var. munda, 470, 472 gumensis, 470, 472 lanzcrotae, 469 nausithoe, 469 obscura, 470, 472 CuspiJt'Un, 2111, 204, 286, J.S'.V Cuvii-rifi, Id, 197, 221 cansochroma, 222 euchroma, 228 huxleyt, 222 Cyanea bougainvillii, 156, 160 Cytaeandra, 1^5 areolata, 140, 154 polystyla, 140 Cyt Dicranocanna, 188 turcillata, 189 Digestion, Intracellular, in C'laspnl.u !• Digitak- medusa, 402 Dimorphism in hvclroids: IV-jinana am! < morpl.a, -!,'; Mnc'iniu and Stamiilia, ^4, ui); Glaums ;mi! Sarsia, 72; lioii^.nn- villia am! NYmcipsis. 172; \j;astia, 1:4: Obclia, 256 I )im ma, 44, 108 occllatum. 4'' Dimmatell.i, 108 c.avus.i, 109 Diocheteumena, 430 Dipetasus, digomnius, }(u Dipklllol), 2S'l paivum, 2^.; Difleurosoma, in, i . 1,1,1'iksii, 214, 'i, hracea, ?-« pacific a, 22j t \ptfiini, 22^ Diplnra, 37 Diplimlla clavata, 76 Dipurena, 7^ cati-nata, 77 cervicata, 76 oiim-a, 76 dolichogaster, 77 K-nilis, <.\i, 77 fragilis, 77 lialttrata, 75 . i, ; i) picta, 77 strangulata, 76 a, 7, I Ij saphenella, //f turfiil'i, rif>, \ppt-tidix, Distribution of: Trafhyiiu-ilus.-^, nula, males am! ttmalrs, ,-71 \)\ sc.innota, 188 ilvsilipltura, 189 Dysmorphosa, 1^5 carnea, 136 cundiioila. i tiubia, 141 t'lilgurans, I ^ gemmifcra, 192 -i.u-ih's 141 minima, 181 mimita, 140 ti inns, 141 , 142 Ectopl Jiini'iitu-ri, (it), Appi'inlix, 4^'S mintrva, 70 ochracea, 'HJ, Appendix, 4^X pacitica, 70 i; I.ir Eirene, II, 232, 2^, ;// danduensis, ,'/ ; naif, 402 gibbosa, 307 kambara, 309 medusifera, ;/ ? fiellucttlii, Apprndi ... guadrigatum, J'l/IS, 7/J riiiJiiln, ;// Eireninte, i i , ' Eleuthena, clap Jni, • allentini, I miruiimi-iit, '• cymbaloides, loll. ,: -f«4 IIU'C I.lll'. 1, 27 I rang l-.ii, li.-il'itH, II, > ^2, link, n, 2o2, .'//'/ bcrmudensis, . JuoJecimalit, 111::, II ' /''" . .-'$J onium, - . < 68 !>f, 10, 231, • ; /. • ^>, 2'n i(l2 nafa, 241) annulate, artii ulaia, 246 campanulata, diaph tllSS''* folk/and fll-il' . 2^2 ••nn!!;ria, 2X5 f/'/ hyaltna, >.|iln|ua, 250 parvigaslra, pul\ '.So polygena, 2f~, 2^1 tyla, 155 p' nt'oiniis, 247 ••,//,/, 10, 2^1. j,-j /i;/(." campanularia, 2 ^ i n-nala, 2 ^4 . I'"1. l')'\ l-.iioipium. 2^4 parv iu.i-.ttum. INDEX. Eucopium pictum, 236 primordiale, 236 Kucoryne, 23 elegans, 25 Eudendrium, ettYct of light i.n regeneration ol, ramosum, 161 Euphysa, 29 aurata, 35 globator, 24 mediti.Trani.-a, 35 u-ntaculata, 53 utrabrachia, 36 virgulata, 35 Euphysora, 29 bigelowi, 36 tetrabrachia, 36 Eurybiopsis anisostyla, 414 Eurystunia rubiginosum, 480 Eiitima, H, 232, 2i)$ brownei, Appendix, 496 campanulata, 29(1, ,'<>->, Appendix, 496 cuenilea, 296, 304 cuculata, 296, Ji/> , nrva, 296, JOO elephas, 296, joo emarginata, 295 gentiana, 296, 502 gracilis, 295 insignis, 296, 299 lactea, 296, 500 levuka, 296, J07 i l-'n-sli- water me Thaumantias lacustris, [99; , 363-365; Microhydra, 366; Linincumla, 370; Moerisia, Appendix, 488 Fusion of blastuhr in Mitrocoma aniuc, 288 1,1, ii, 2}2, 2jg ovali s, ?Sl I ,://.!/, I. 280 tllllltla, 2f<) ( 1. 1 st null's, 460 paiasiticum, 461 ii.-mtnaria, 85 cladophora, 90 dichotonia, i)l •-88 implexa, 89 nitida, 91 sagittaria, 88 ( i. nil cells, origin of: IVnnaria, 25, 146; Dend- roclava, 117,490; Podocoryne, 136, 139; Hou- gainvillia, 162, 163; Obelia, 239, 251, 253, 254; Cunina, 479; Sarsia, Appendix, 488 Geryoncs, 424 (/. i v"'"'', 14, 4°0. •/-•/ appendiculata, 413 bicolor, 413 hiu-ntaculata, 294 dianasa, 425 rxigua, 413, 420 fungiformis, 425 hastata, 425 hexaph}'lla, 425 in. \icana, 425 octona, 123 pellucida, 314 probosciJalis, 4.25 rosacea, 417 tetraphylla, 417, 418 G, i yontJte, 14. -f°9 ( ;, n.mopsis, 311 forbesii, 311 gentiana, 302 pellucida, 314 Glands in I.ymnorea alexandri, 75, 155 Globiceps, 23 globator, 24 tiarella, 25 Glossocodon, 410 catharinensis, 421 liajckt-lii, 421 liitkenii, 418 mucronatum, 413 tenuirostris, 416, 421 Glossoconus, 410 [vi] [NDEX. Glossoconus canariensis, 418 Gonads, position of, secondary : of Slabbcria lialttr- at;i, 76; perradial, in Katlikca, ir?sstis, 342, ,'/V Kraftin}; of, j/i) home Mi, 342, ;_y> iniiilnii-liii, ^42, ,'/ ,\ 41 (S ins svstt-ni, .|4'' pilagicus, 342, 349 a nsis, 342, ;/i; U2, ?« ( lon\ nenia, 341 ' .iroa, 293 mirabilis, 294 Gossea, 13, jd/ brack \'in circiniata, 367 lu-tt-s, 367 (iHmtli, r:ite of in hydroids: Sarsia, 5^; I5ou- gamvilha, 162; Obeli. i, 246 ( lymnopthalmz, 17 Habits: Collapsing of Dipleurosoma, la\ing of Stomotcca, Il.j; ( )i-r:.ni.i, 14^; .Equorea, 328; < lonioMcmus, ,'^4; l.iriopc, 414; Geryonia, 42^, I-'i-nlui!; of /.uu Ic .1. 89 Turns, 126; Swimming of Obelia, 24^; (ion- ionemus, 344; Cubaia, 351; Olindias, 355; Craspedacusta, 365 Halatractus, 31 llnlcordyle tiarella, 25 llalicalyx, 352 tenuis, 354 Htiltfreas, 14, } ma. 160 I'liiKtata, platynastt r, 105 p\ raniid.ita, i Mlpt'li lll.lils. l62 . '4. 377, •ill'*', 393 amflum, rlon^atum, 379 ni:i. rogasti i , null fl. : it/a-, ^(^ tyfifitin, ampliipli in US, }Q .iilii-onn-;, 39 , liil.mif, fj : linstni.i-. /_' forbesii, /_• n .Inns, 39 . oividi-ntalis, 42 // , 41 firnlifi i , ftii II 111: U 1 1\ ilraitc n.i, 4^S Ilyilrai-tinia au.ilaia, 140 nun > ,15, 44^, /.is' salenskii, In in •, .;i i [vii] i lea, 304 ijibbosa, 507 mollis, ^u palki-nsis, 309 pellucida, 314, Appendix, 496 INDEX. Irene viridula, 31 I lieninpsis primnidialis, 351 Irenium, .; i i quadrigatum, 313 /1,-ti'if^iis, 1 I, 232, ?/(' /(, \nn, mahs, ;/<> Isonema, 3X3, amplum, Kermin IKTIH , I 22 Kollikilia fascicuh'ta, 171) Lat'ci-a, 201 caK.nala, 204 coinuta, 2OI Laodice, 2OI eellulaiia, iijli, I'ji) indi. a, 2 i2, i"4 Laodii . .'•-,, -'"i caK-aiat.i, J i, ' '4 ( i ! rhapinam, ' 6 CTU ata, 'Ol ( ' I • Vk li|)l , 2O6 i i i !> mlis, 206 fijiana, .?<>•," vai. indica, 205 maasi, 205 mai.i;n:\ '. '. 204 ( ?) nepluna, 206 piii, hra, 202, 2oj ulothrix, 202, 204 Laoniedi a, i^N dichotonia, 244, 24^, 255 divaricata, ' i ; m l.innosa. 244, 247 •M 1M. 111. II. I, 24U Lar sabellarum, 193 Leptomt-ditsie, g, /i/>, 231 Lessonia, 397 Leuckartia, 424 proboscidalis, 425 ,13, 370 : iml :Li', 13, l6g Limnocodium, 303 sow riliii, 3')^ victoria, <'••; Limnorea, i ^ ,' IKII \cgica, 154 proboscidea, i ^ ^ Liriantha, 410 catharinensis, 421 nuR-ion.it::. (14 n iiaplu-lla. 418 Linof>, , 14, 4.09, //" appcndiculata, 411, 413 . 41 1, jiS catharinensis, 412, 421 rasiformis, 411, -/r? cerasus. ;i < omipacta, 417 s, 412, jit) crucifera, 417 ilistiinognna, 412, 420 ,'iu \lnii, 412, /_'« .•\igiHi, 411, ^/J li,i,;-ki-lti, 412, _/J/, Appi-ndi\, li\ralina, 421 /; yperboltca, -j i<< unli, ,1, 41 2, ^-?; lifiutina, 420 lntk,-nii, 412, //.V minium, 412, 7-'^ »/ll, inimtil, 411, 413, /'-/ proboscidalis, 425 ii /''I, ^f-, AppL'iulix, 4117 r, utigera, 412, 413, 411;, /-'/ tenuirostris, 41(1 ti'li\ll•_, _ rrmlra, 153 Mahella gracilis. i JQ \tisotias, 13, ^i^X Margelidic, 102 Mill i'f/n;,r, / ,; \ [argelis, i ^ autumnalis, 169 carolmensis, 165, 167 nordgaardii, 168 principis, 160 rannisa, 161 trinema, 171 zygonema, 164 Margellium, 175 grata, 179 octopunctatum, 177 'Mll,r. 6, 2O ris, fi, ?0 [viii] hteckelit, So hartlaubn, 82 stylostoma, Si IXDKX. Marmanema, 376 clavigerum, 382 mammseforme, ^ n inpaniun, , MH -radia, I y$, '54 Mi-dusa xquorca, 202, 324, bimorpha, 522 campanulata, > iX l-n-llllll pl'lisilr. '.{ ^ cmciata, 201, 202 cymbaloidea, 2'>X i;li>liul.nis. ^^ hemisphaerica, iiuinna, 1 .[X mucilaginosa, 4X1 patina, ,'25 pilrata, 123 proboscidalis, 41^ saltatrix, 210, 22O \lrliivtta, 2O/ digitale, 402 fasciculata, 17*) plrmostoin.i, 146 Melicertella panocto, 209, 210 Melicertidium, 207, 209 campanula, 207 octocostatum, 208 \l,h, iitnite, 9, IQJ M.li.-crtissn, (), 197, 2O<) fltii'tgi rn, Jlo malaytca, 211 Mi-li, ,itnm, 9, 197, so'/, 2IO fiinipnmi/ii, ji)~ p, orgii '-mi, soy nctncostatiin. . pnnocto, 209 penicillatum, 218 ( ':) proboscifcr, 209 Mi-siun in.i, 211, ^24 abbrt-viata, ^^ li.iiiilu, 326 ccerulescens, 326 tlubium, 32^; eurystoma, 325, 327 nUKTOll.il t\ 1.1, H ,' pi-ncile, 333 |)ilcus, 211 victoria, 330 .nnfinnii, ^. /{ ' I I Mi: rohydra, i i,, ;iV> n, ^66 MiiTostoma, 92 ambigua, 92 Milli-fora, 16 ',rnis, 16 Mill, porinte, mrdus.r <>f, ir> n, i r, 232, 25>'. unn.r, 287, 288, 290 Mltt'i. ',111:1 : III, It.!, . cruct.ita, discotdea, lenJenjeldi, 290 i/uta, 289 mtnerva, polydiademata, Mill-in diiiclla, 2S«i fulva, 290 pi)l\ 290 Minocomiiiin, jX'i cirratuin, iSS parasites, 'i-iia, 71, 14^, 14(1, 14- isin, Appnulix, 4SX l\'ntisi. Appendix, 4X8 Malli, 111,1 nil diisa. 445 a< liiiiin j Monocaulus prinlulus, 41 Multioralis, Cl\ .|]|S, 2Xl 'iii;i[i of, }, i ^. /"", v X, Xi.i, ;-_•, \ppiiuli\, '"•< I, '7i f I Hi I j, 111. lf^ "ililn-sii, 82, 173 liiti-rnni ma, I 7^ tt>,:ii;i, ' . mill: nils, 2-»i-iu^i:i-, 254, 255 bii-uspidata, 254 bidentata, ' -,4. Appt-ndix, /,;,' bit'un-ata. 4115 ill', - /it chinentis, commissuralit, J//, Appendix. , until,., i diapliana, 24^, 2^2 dit'li'il'iniii, 244, j^rt ill\ aiu-af :i, -147 Juliiii, 24'\ H.ihi-llata, 241; fnigilis, JiJ gelatinosa, _•// INDEX. Obeli a gracihs, 253 griffini, 252 gymnophthalma, 244 helgolandica, 253 hyalina, 248 leucostyla, 244 linearis, 257 longissima, 255 luciiera, 249 nigra, 256 nigrocaulus, Appendix, jyj. plana, 2./p filicata, 2$6 polystyla, 255 purpurea, 243, 256, Appendix, 494 pyriformis, 24.7 rhunicola, 246 serratula, 257 sphrcrulina, 246 striata, 24.8 surculans, 2$2 Ol.Jitur, 10, 231, 232 Oceania, 8, I2O, 146, 265 ambigua, 274 armata, IJ-J blumenbachii, 177 brunescens, 274 carolinae, 275 coccinia, 123 conica, 118 coronata, 123 dinema, 109 discoidea, 272 flavidula, 147, 266 folleata, 264 gelatinosa, 272 globosa, 122, 272 languida, 269 magnifica, 269 mccradyi, 271 octocostata, 208 octona, 123 pacifica, 273 phosphorica, 355 pileata, 123 polycirrha, 143 saltatona, Il8 sedicimcostata, 1 18 singularis, 273 tetranema, 106 tubulosa, 52 turrita, 123 viridula, 311 Oceanidts, 7, 17, 102 Oceanopsis, 281 bermudensis, 282 Octocanna, 12, 320 octonema, 325 polynema, 320 Octogonade, 12, J2I mediterranea, 322 Octonema, 2OI eucope, 206 gelatinosa, 214 Octorchandra, 295 canariensis, 302 germanica, 302 orientalis, 496 vanabihs, 312 Octorchidium, 305 tetranema, 302, 306 Octorchis, 295 campanulatus, 302 gegenbauri, 302 orientalis, 299 Octorphalon, 2OI fertilis, 206 Oli n Jiada, 12, 340 Olindias, 12, JJ2 malayensis, 353, 356 mulleri, 355 phosphorica, 353, 555 saml/i/ijuiensis, 353, y^ singularis, 353, 357 tennis, 353, 354 Olindioides, 13, 358 formosa, 358 Orchistoma, 9, 197, 211 agartcifortne, 212 pileus, 211 steenstrupif, 21 1 tentaculata, 212 Pachycordylf, 5, 20, 21 Jcgeneratus, 21 weistnanni, 21 Pachysoma flavescens, 434 Pandasa, 1 16 Pandea, J, 116 conica, 118 flavidula, 147 maasi, III) minima, 118 saltatona, Il8 violacea, ug, Appendix, 490 Pantachogon, 14, 388 apsteini, 405 hcsckelii, 381) rubrum, 381) Parasitism: Hydrichtliys, 19, 6j; Mnestra, 96; Stylactis minoi, 149; Cunina, 379, 425, 427, 429; Cunoctantha, 461, 4.64., 4.65; Gastrodes, 461 Parvanemus, 21 Pectanthis, 372 asteroides, 374 Pectis, 372 antarctica, 375 Pectyllidae, 371 Pectyllis, 372 arctica, 372 Pegantha, 15, 430, 439 INDEX. Pegantha aureola, 440 clara, 445 cyanostylis, 441, .;/,- dactyletra, 440, / / / dodecagon, i, y./ / goJeffroyi, U> Ln-is, 444 I unul at a, //<< intigiti/ii it, ,j / Iriloba, 440, .^/j '•fn, ./.// l'i M mthid.e, 420, 4^1 Pi • .isia, 439 dodecagons, 444 Pelagic hydroids: Margelopsis, So; Pelagolmlra, 83 /'. lagohydra, 6, 83 mtrabilts, 83 .mi, 5, 23 adamsia, 2j cavolini, 24 disticha, 2J, Appendix, 487 gibbosa, 25 mornata, 4^- marina, 24 pacifica, 28 rosea, 2J symmetrica, 24, 25 titir,lln, 2$, Appendix, 487 vitrea, 28, Appendix, 487 Perigommus, IOQ cidaritis, IIJ joncsn,'! 14 minutus, 124 napnlitanus, 109 ii pens, 124 schneideri, 109 steinachi, 109 sulphureus, 80 vagans, Appendix, 490 1','t wj, 14, 406 dissogonima, 407 incolorata, luierna, 407 Petachnum, 360 tiaropsis, 361 I'et.isata, 360 eucope, 361 rabbeana, 361 Petasina:, 13, jdo Petasus, 13, 360 atavus, 361 t, tfiinema, 361 I'liialella, 234 Pliialella t'alklandica, 237 I'/iialiJium, II, 232, 265 atnbiguum, 274. ampullaceum, 123 brunescens, 2J^ buskianum, 2JO cyrnbaloideum, 235 duodecimale, 2Kj gelatmosum, 272 globosum, 2"J2 gregarium, 2J2 lieriiispha;ricum, 266 iridesccns, 273 languidum, 261), Appendix, IIIIIKL-, Appendix, 495 pacificum, 273 simplex, :j^ singularis, 2J$ ic mporarium, 266 ii'iiue, 310 variabile, 235, 266, 280 variabilis, 270 PliiiiliniF, 232, 261 Phialis, 286 cruciata, 288 Phialium, 281 bakeri, Appendix, 495 dodccasema, 283 duodecimalis, 283 Phialopiis, 232, 266, 276, Appendix, 495 comata, 2j6 diegensis, Appendix, ./i tropica, 191 vanans, 194 Protiara, 7, 71. JOJ beroe, 106 borealis, 106 formosa, io"j ha'ckclii, 106 }'s,n,lofl\tia, II, 232, 2j8 gardineri, 2JQ pentata, 265, 2-jS mil, 6, f)2 ambiguum, 92 darwinii, Q2 Ptychogastria, 13, 57^ Ptychogastria asteroidt-s, 374 polnns, _^J Ptychogastridee, 13, 577 Ptychogfna, 9, 197, Jl-/. californica, Appendix, ./(>/ ervthroponon, J/7 / o / 1,1, It'll, _'/ f longtgona, 2ij , pinnulata, 215 var. intermedia, 215 Pulsation of: Comic pusilla, 51; Sarsia, 52; Polyorcliis, 219; Obelia. 245; Craspedat-ust.i, 365; Gonionemus, 348; ( leryonia, 426 Purena, ~ ^ brownei. Appendix, 489 "emniifera, 62 strangulata, 76, 79 Rutliki-n, 8, 775 blumenbachiana, 177 blumenbachn, i~~ ,!,•« uns, /iS'/ fnsi ii ulata, if(> formosissima, ijf octonemahs, iSn octopuuitiitti, 177, Appendix, 495 var. grata, 179 Reactions to: light by Eudendrium, 4; Sarsia, 52; mechanical stimuli by Rathkea, 180; ehemi- cals and electric current by Polyorcliis, 219; chemicals by Obelia, 243; mechanical stimuli by C'osmetira, 261; photic and mechanical stimuli by Eutimium, 306; light and other stimuli by Gonionemus, 347; various stimuli by Craspedacusta, 365; chemicals by Gery- onia, 424, 427 Regeneration: Eudendrium, 4, 27; Pennaria, 25; Obelia, 239; Tubularia, 239; Tima, 318; Gonionemus, 346; Liriope, 410; Gcryonia, 427; Solmaris, 436 Rhacostomn, 524, 335 atlanticum. 335 dispar, 326 Rhegmatodes, 324 floridanus, 330 globosa, 332 lacteus, 333 tennis, 332 Rhopalonema, 14, J7<5 cltruigerum, 382 ,ir uleum, v^'n polydactylum, 379 striiituin, jSl tvpicum, 578 1'i-lntiim, 377, 378 Rhopalonemtnee, 14, ^J-6 Sabellana, 112 Saphenella, 234 dissonema, iri, II, 108, 232, [xii] INDEX. Saplicnia balearica, 293 bitentaculata, -•<;/ dinema, ion, ii > / gracilis, zyj titania, 109 Snrsia, 5, ft uiigtilata, 60 apicula, 59 ban.-nt.sii, 55 brachygaster, JQ i-lavata, 77 cocci 'h, tra, App> mli\, 4XS codonophora, 61 ont ter, 77 , 57 flammea, 6f, 120 Xi'ininiffra, 6? "ladalis, s ,' gracilis, 60 hargitti, 63 macrorhyncha, 52 nil nun n, 59 mirabilis, 53 var. reticulata, 57 nodosa, 48 prince ps, 60 prohfera, 6l f'lil.-lhlLi, 57, Appendix, 4S'X radiata, vS1 resplendent, Appendix, 4X7 rosarta, 59 siphonophora, f>2 strangulata, 79 tubulosa, 52 turricula, 57 (Stauridiosarsia) prnJnt / Sarsiantf, f, 20 Sarsiella, 44 Schizocladium, 2^S Scrippsia, 197, \j>prn.li\, 4,^ [>,!,- lp, 'I, A|)|)ciuii\, 4., ^ Si -\ plus mucilaginosa, 4X1 St.ismial dimorphism: I'rnnaria. -!'', Saisia, 5^, 55 Sertularia dichotmna, 246 tulatinosa, 244 gcniculata, 249 longissima, 255 pennana, 24 volubilis, 262 Sexual dichromatism: Stomotoca dinema, 111; < )n-histoma pilcus, 21 1 Sibogita, 8, 186 rtrica, 1 86 nauarchus, Vppendix, 4<)i simulans, 187 /V/M, .\|i|)cndix, 491 s, 293 bitentaculatus, 294 insignis, 299 Slabbena, 6, 75 Slabberia brown, i, Appendix, ""'•', 77 halterata, 75 ophiogastt pyramis, strangulata, ~6 ' . fragilis, " Slllllltll,',!, 14, leptogaster, ^- •iipanuin, ^78 I ,. , • , ; ,'_> . 444 corrj,,,,, 432, ; coronantlia, 437 /?«',..,,;;>, 4^2, 433. /,'/, 4X4 fnrskulii. 432, ,/;; •j. nhaiiri, 437 iiu-isa, 4 Si ^ nisflllpt.l, 4 tj /.•»//, H/I;, 4^2, / ;V ostyla, 4.32, nuu-ila^iiiiisa, 4X1 iiniltil'Jiiitii, 4^a, f punttara, 444, 4 v /i"'' Solmundus, elacialis, 472 tetralinns, 4^2 retrain mils, 472 SpirocoJon, 9, 197, sultatrix, 22O Stauraglaura, 14, /cA 1,'tl ,li"ll!: IIK1, jOll Stauridia producta, 65 Stauiiilii-. 99 Si.iuijiliiini, 64, productun StauriJiosai '/•;. s. ('I Stilur'iJis.lif. 0, !<)/, -1/?, 221, 22S hit . f{ niprii-anv, 2*21 tftriisttinriis, 21^. Staurophora, it, 2^2, 291 jillL-liltl,!: kiitliii, • laciniata, fxiii] INDKX. Staurophora niertensn, 291 Staurostoma, 291 arctica, 292 Stft-nstrupta, 5, 2$ aitrata, 35 austrahs, J7 bigelowi, 36 cranoides, 31 galanthus, 31 globosa, 36 gracilis, 31 lineata, 31 occidentalis, 42 rubra, J7 tetrabrachia, 36 virgulatti, 55 Stenyo, 47 Stomobrachium, jJJ lenticulare, $22 octocostatum, 208 stauroglyphum, 323 tentaculatum, 322 Stoinotoca, J, loS apicata, 109, 112 atra, III australis, 1 1 1 dinema, 109 divisa, 114., Appendix, 490 jonesii, ir4 octicJra, III, Appendix, 490 periphylla, 113 pterophylla, 77J rugosa, 112 Stvliictis, 8, 149 arge, 757 fnriola, 141.) hooperi, 750 minoi, 149 Syncoryna cleodora;, 122 Syncoryne densa, 53 eximia, 57 gravata, 52 linvtllei, 7'> 72 producta, 63 prolifera, 61 reticulata, 57 rosana, 5p sarsii, 52, 60, Appendix, 488 Syndictyon, 47 angulatum, 53, 59, 60 reticulatum, 57 Tentacles, hydra-like tentacles of Moensia, pendix, 488 Tetracannota, 224 collapsa, 226 Tetranema jeronauticum, 235 eucopium, 199 Tetrorchis, 388 erythrogaster, 388 Thalassanthea;, 428 Thamnitis, 8, 7J2 tctrella, I°j2 Thamnostoma, 153 macrostoma, 153 Thamnostylus, 8, IJI dincma, 7J7 Thaumantiada, 9, /p6 T li.intnimti/is, 9, 197, buskeana, 270 cellnlaria, 198, 7p£> corynetes, 367 cymbaloides, 235, 311 eschschnltzti, 198 forbestt, IQQ globosa, 235 hemispliaerica, 266 inconspicua, 266 lacustris, 7pp leucostyla, 266 lucifera (lucida), 250 m&otica, 2OO mediterranea, 2O2 melanops, 266 milleri, 208 multicirrata, 259 pilosella, 261 plana, 249 punctata, 355 quadrata, 200, 235 rubrum, igg thompsoni, 199, 270 undulata, 202 Tholus eurygaster, 383 Tiara, 120 coniferi, 128 intermedia, 123, 125 oceanica, 125 octona, 123 papilis, 123 |iapua, 125, Appendix, 491 prismatica, 125 reticulata, 125 rotunda, 124 sarsii, 123 smaragdina, 123 superba, 126 Tiarella parthenopaea, 127, 147 Tiaricodon, 71 coeruleus, 73 Tiaridse, IO2 Tiarin Timoides, 9, 197, 2/2 agassizii, 212 Toxorchis, IO, 197, 22, ainbigun, 92 cladophora, go costata, 8j Appendix, 4X1 inif'l \,,. .Vi; nit id a, gi L'opsis, 6, gi dichotoma, gi Zygocanna, 12, 337 costata, 338 pleuronota, 33$ purpurea, Zygocannota, 337 purpurea, 338 Zygocarinttln, 12. diploconus, 359 undulosa, 3^9 Zygodaetyla, 12, 324. 533 crassa, ^6 cubana, 325 cyanea, 326 granlandicus, ;;-,- rosea, 325 vitrina, 32^ [XV]