TRACHYMEDUS.E — AGLAUROPSIS, CRASPEDACUSTA. 363 



canal. Each lithocyst contains a single (ectodermal ?) concretion. Radial-canals and ring- 

 canal very broad. Stomach somewhat cone-shaped and about half the length ot bell-cavity. 

 Mouth with 4 large, perradial lips with a folded margin. The gonads are transversely divided 

 lobes and occupy nearly the whole length of the radial-canals, but are separated by short 

 spaces, both from stomach and ring-canal. Common at Stanley Harbor, Falkland Islands. 



Genus CRASPEDACUSTA Lankester, 1880. 



Craspedacusta, Lankester, 1880, Nature, vol. 22, p. 147. 



Limnocodium, Allman, 1880, Nature, vol. 22, p. 178; Journ. Linnean Soc. London, vol. 15, p. 13 1 .— Gunther, 1894, Quart. 

 Journ. Micros. Sci., vol. 5, p. 539 (finds tentacles hollow).— Goto, 1903, Mark Anniversary Volume, pp. 17, 18.— Potts, 

 1906, Quart. Journ. Microscop. Sci., vol. 50, p. 623.— Browne, 1906, Quart. Journ. Microscop. Sci., vol. 50, p. 638 — 

 Oka, 1908, Annot. Zoolog. Japonenses, vol. 6, p. 225. 



Limnocodium (Craspedacustes), Lankester, 1880, Quart. Journ. Microscop. Sci., vol. 20, p. 351. 



The type species is Craspedacusta sowerbii Lankester, first described by Lankester, later 

 by Allman, from the fresh-waterlily tank containing Victoria regia in Regent's Park, London. 

 The genus appears to be separated from Aglauropsis only by the elongate cavities in its velum 

 which contain the sensory-clubs, having concretions of entodermal origin. 



GENERIC CHARACTERS. 



Trachymedusae of the family Petasidct. Numerous hollow tentacles projecting at various 

 levels from the sides of the bell above the margin. The entodermal cores of the tentacles are 

 continuous with the entoderm of the ring-canal. Numerous entodermal lithocyst-clubs inclosed 

 in closed elongate cavities within the gelatinous substance of the velum. The lithocyst cham- 

 bers are lined with ectoderm, which also incases the entodermal cores of the sensory-clubs. 

 4 radial-canals and a ring-canal. No centripetal canals. 4 gonads on the 4 radial-canals. Man- 

 ubrium tubular, with 4 lips. The hydroid attributed to this species is devoid of tentacles and 

 with a terminal mouth. Medusa-bud produced at the oral extremity of the polypite. 



The generic name Craspedacusta was first proposed by Lankester in his published account 

 of the medusa in Nature, vol. 22, p. 147, on June 17, 1880. On the same day Professor 

 Allman read a paper upon the medusa before the Linnean Society of London in which he pro- 

 posed the generic name "Limnocodium." He did not publish this name, however, until June 

 24, 1880, when it appears in his paper in Nature, vol. 22, p. 178. If it be true that generic 

 names must date from the time of printed publication, the name Craspedacusta clearly has 

 precedence over that of Limnocodium. The medusa has, however, been commonly known to 

 literature under the name Limnocodium sowerbii, the generic designation being derived from 

 Allman and the specific name from Lankester. This evidently violates the accepted rules of 

 nomenclature. 



Regretting, however, to revive an unfamiliar name to supplant one very familiar to all 

 students of the medusae, I applied, on August 28, 1907, to the International Commission on 

 Zoological Nomenclature for permission to retain the well-known name Limnocodium. This 

 petition was answered in the negative as follows: 



[Opinion Rendered by the International Commission on Zoological Nomenclature.) 



Summary. — Craspedacusta sowerbii Lankester, 1880, June 17, has clear priority over Limnocodium 

 victoria Allman, 1880, June 24. Presentation of" a paper before a scientific society does not constitute 

 publication in the sense of the Code. Publication defined. The Commission is without authority to 

 sanction usage in contravention to the provisions of the Code. 



Craspedacusta sowerbii Lankester. 



Craspedacusta sowerbii, Lankester, ]88o, Nature, vol. 22, pp. 147, 177, 190, 241. 



Li in not odium victoria, Allman, 18S0, Nature, vol. 22, pp. 178, 218, 290. 



Limnocodium sowerbii, Romanes, 1880, Nature, vol. 22, p. 179; 1881 , Quart. Journ. Micr. Sci., vol. 21, p. 162 (physiology) — 

 Lankester, 1893, Nature, London, vol. 49, p. 127 (appearance of the medusa in the Victoria regia tank at Sheffield, 

 England).— Gunther, 1894, Quart. Journ. Microscop. Sci., vol. 35, p. 539, plate 40 (histology).— Vanev & Conte, 1901, 

 Zool. Anzeiger, Bd. 24, 533, I fig. (found at Lyons, France,' in a waterlily pond; figs, of spermatozoon).— Potts, 1906, 

 Quart. Journ. Micr. Sci., vol. 50, p. 623, plate 35, figs. 1-1 1 (reproductions of previous figures of hydroid and medusa). — 

 Browne, 1906, Quart. Journ. Micr. Sci., vol. 50, p. 638, plate 37, figs. 3, 5.— Maas, 1907, Zeit. fur Allgemeine Physiol., 

 Bd. 17, p. 1.— Hargitt, 1908, Biolog. Bulletin, vol. 14, p. 304, figs. 1-7 (found at Washington, D.C.). 



Limnocodium (Craspedacustes) sowerbii, Lankester, 1880, Quart. Journ. Microscop. Sci., vol. 20, p. 351, figs.; 1881, Ibid., 

 vol. 21, p. 119, plates 8-10. 



