Bulletin of Museum of Comparative Zoology 37

BULLETIN OF THE MUSEUM OF COMPARATIVE ZOOLOGY AT HARVARD COLLEGE, IN CAMBRIDGE VOL XXXVII CAMBRIDGE, MASS., 1900-1901 U S A University Press : John Wilson and Son, Cambridge, U.S.A CONTENTS Page No — Descriptions Atlantic No of — Some Medusa — Contributions and the from the Tortugas, ^44 Plates.) (h 'Florida Plates.) at June, 1900 By Alfred Golds- July, 1900 from the Zoological Laboratory of the Comparative Zoology Mark Little-known Medusae from the Western By Alfred Goldsborough Maver BOROCGH Mater No New and 11 Museum of Harvard College, under the direction of E L The Regenerating Nervous System of Lumbricid^ Centrosome of its Nerve Cells By Herbert W Rand, (o Plates.) No 126 September, 1901 83 f o Bulletin of the Museum of Comparative Zoology AT HARVARD COLLEGE Vol DESCRIPTIONS OF XXX VII No NEW AND LITTLE-KNOWN MEDUSiE FROM THE WESTERN ATLANTIC By Alfred Goldsboeottgii Mayer Willi Six Platks CAMBRIDGE, MASS., U.S.A.: printp:d for the museum June, 1900 Bulletin of the Museum of Comparative Zoology AT HARVARD COLLEGE Vol UESCllIPTIONS OF XXXVII No NEW AND LITTLE-KNOWN MEDUSiE FROM THE WESTERN ATLANTIC By Alfred Goldsborough Mayer With Six Plates CAMBRIDGE, MASS., U.S.A.: PRINTED FOR THE MUSEUM June, 1900 No — DescriiJtions of Western Atlantic New and Little-known Mcduscc from By Alfred Goldsborough Mayer the LIST OF SPECIES SCYPHOMEDUS^ Bathyluca Solaris, nov gen et sp HYDROMEDUS^ Bougainvillia Gibbsi, nov sp Lymnorea borealis, nov sp Oceania carolinae, nov sp Oceania singularis, nov sp Octonema gelatinosa, nov sp Orchistoma tentaculata, nov sp Stomotoca apicata, L Agassiz Stomotoca rugosa, nov sp = Stomotoca apicata, Fewkes Syndictyon angulatum, nov sp CTENOPHOK^ Mnemiopsis McCradyi, nov sp The Medusas described in the following paper were obtained by the author as assistant to Mr Alexander Agassiz in collecting new material for a work upon the Medusa-fauna of the Atlantic Coast of North America will descriptions of Western-Atlantic Medusai herein given also in the new edition of The North The eventually be published American Acalepha? now in preparation Eight species are new; Ctenophore, and of these six are by A Agassiz and A G Mayer one is a Scyphomedusa, one a In addition to these there is Hydromedusoe one Hydromedusa (Stomotoca rugosa) that we have redescribed under a new name VOL XXXVII — NO 1 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY The Scyphomedusa (Bathyluca Solaris) is, judging from its structural a deep-sea type, although the single specimen from wliich our figures were obtained was found upon the surface of Narragausett aftinities, Bay, Rhode Island The Medusce described in this paper were collected at different times at Eastport, Maine ; Newport, Khode Island ; Charleston, South Caro- and lina; localities in the Bahama Islands during visits at the suggestion of Mr, made to the above Agassiz SCYPHOMEDUS^ BATHYLUCA, Bathyluca nov gen Solaris, nov gen Figs 1, 2, Plate et sp A single specimen of a new genus of Discomedusa belonging to the family Ephyridne was found in Narragansett Bay, Rhode Island, on July 27, 1896, by R W Hall, Esq The medusa was found floating upon the surface, but as it was very much torn and battered, and as it differs widely from any of the pelagic medus£e of our coasts, we are inclined to suspect that prove to be a deep-sea form, a specimen of which has wandered to the hitherto it may known surface Generic Characters ciform, central — Bathyluca, nov gen Discomedusse with a simple cruor palps There are mouth opening, without mouth-arms 16 wide, radial, gastro-vascular pouches (8 ocular and tentacular) There no ring canal There are marginal sense-organs and 16 marginal ten- is tacles There are gonads in the oral sub-genital pits floor of the disk, and there are — The umbrella is flat, and the gelatinous substance is Specific Characters It is 45 mm in diameter, and about 10 mm in height The quite thick aboral surface of the umbrella is sprinkled over with small clusters of nematoThere are marginal sense-organs that are deeply sunken within small The entoderm of these sense-organs contains no niches between the lappets There are 24 pigment, but instead there are small white granules (Figure 2) cysts The mouth opening is marginal lappets and 16 long hollow tentacles cruciform in shape, and there appear to be no mouth-arms or palps We may, however, be mistaken in regard to torn and battered, and There this, for our specimen was is of the lower floor of the gastro-vascular cavity, and their position is by horseshoe-shaped ridges upon the lower floor of the sub-umbrella are a much possible that the palps may have disappeared The gonads are found in the entoderm are wide sub-genital pits it number marked There of long gastric cirri that arise from the regions of the gonads ilAND — Nerve-Cell Oentrosome PLATE All the figures magnified 2000 diameters Fig 38 Fig 39 (with several of the neighboring nuclei) from the anterior end of a cord of 34 days' regeneration Iron-haematoxylin Small cells with resting nuclei from the anterior end of a cord of -34 days' Young cell regeneration Each of the two cells has a centrosome Iron-haema- toxylin mass of cytoplasm than in the cells of Figure 39 centrosome and radiations From a brain of 34 days' regeneration Fig 40 Cell with a greater Fig 41 Figure 40, from a brain of 37 days' regeneration centrosome and radiations Iron-haematoxylin Three cells from the anterior end of a cord of 34 days' regeneration A ; Iron-hsematoxylin Fig 42 Cell, similar to that of ; centrosome witli radiations may be seen near each of the two larger Iron-haemanuclei, on the side toward the greatest cytoplasmic mass i toxylin Fig 43 Two cells from Figs 44, 45 the epidermis of a normal worm The centrosome deeper end of each nucleus Iron-haematoxylin is at the Cells from regenerated epidermis, showing centrosomes and radia16 days' regeneration Acetic-sublimate, Kernschwartz and tions safranin Plate Rai.id.-Ner^/e-Cell Centrosome 39 A ^N' 42 40 A V-^ • *.» ; y ctz, V ctez, 45 43 e^ 41 C^O ctSo- 44 % HVffl.del • Rand — Nerve-Cell Centrosome PLATE All the figures magnified 2000 diameters Figs 46-52 Dividing or recently divided a worm, cells from the regenerated epidermis of after 11 days' regeneration haematoxylin Hermann's plat.-acet.-osm., iron- See pages 146-147 for a discussion of the membranes PlME Rand -Nerve- Cell Centrosome ctd, ctiz 46 47 ôi^ y It 7?a,/5 ciXiL 50 49 cZ(i ^ I m ills I & 51 eta J HWR.deI H^ 48 'WN mi mi: \ '% It y eJ&t' 52 Rand — Nerve-Cell Ceutrosome PLATE All the figures magnified 2000 diameters Figs 53-56 Recently divided subepidermal or basal cells of the old epidermis, The centrosome to four segments back of the segment cut days after the operation of mitosis persists in the resting cells from one Hermann's Fig 57 plat.-acet.-osm., iron-haematoxylin of cells, with nuclei of the epidermal type, from a thin layer of cells lying directly beneatli the regenerated epidermis of a worm of 11 Group Hermann's plat.-acet.-osm., iron-haematoxylin from the layer of cells mentioned in the explanation of showing peculiar conditions as to the presence of a nuclear days' regeneration Figs 58-60 Dividing Figure 57, membrane cells See page 149 iiAiMD.- Plate Nerve- Cell Centrosome 53 55 54 ^ ^ ^ +Vw 56 57 ''^'Sr;^ y r I • ••> '•• 58 I It t / v^• i /^r.vr ^ TTib 77t^ nl 60 nih.nl 59 ;7i^ mb nl \ #• EATR del The following Museum Publications of the are in preparation Reports on tlie : of Comparative Zoology — KesuUs of Dredging Operations in 1877, 1878, 1879, and 188", in charge of Alkx" by the U S Coast Survey Steajner Blake," as follows: ANDER Agassiz, E EHLERS The — Anneliils of the " Blake.'' HAKTLAUB The Coniatulie of the " Blake," «itb 15 Plates LUDWIG The Genus Pentacrinus MILNE EDWARDS and E L BOUVIER Tlie Crustacea of C H A VERRILL A E The Alcyonaria of tlie " the "Blake." Blake." Reports on the Scientific Results of the Expedition to the Tropical Pacific, in charge oi' Alexanukr Agassiz, on theU S Fi.-h Comniiss^ion Steamer "Albatross," from August, 1899, to March, 1900, Commander Jefferson F Moser, U S N., Commanding North American MARINE INVERTEBRATES, from Drawings by BuuKHAUDT, SoNKEL, and A Agassiz, prepai'ed under the direction of L Agassiz Illustrations of LOUIS CABOT Immature E L MARK State of the Odonata, Part IV Studies on Lepidosteus, coiitinue