OBELIA. 91 



Eucope ? divaricata A. Agass. 



Laomedca diniricala McCr. Gyiiin. Charl. liar!)., p. 03. 



An examination, by Professor Clarlv, of the reproductive calyeles of" 

 specimens collected at Charleston by Professor Agassiz, shows that the 

 Medusae have forty-eight tentacles. The Hydrarium is closely related 

 to that of the Uifcojje i^iirlformis, which, together with the i:)resent 

 sjjecies, Avill probably form the basis for a new genus. 



Charleston, S. C. (L. Agassiz). 



Cat. No. 82, Charleston, S. C, January, 1852, L. Agassiz. 



OBELIA Per. et Les. 



Obelia Per. et Les. ; in Ann. du Mus., XIV. p. 43. 1809. 

 Obdia Agass. Cont. Nat. Hist. U. S., IV. j). 351. 18G2. 

 Obelia McCk. Gymn. Cliail. Ilai-b., p. 94. 



Obelia commissuralis McCr. 



Obelia commi^auralis McCr. Gymn. Charl. Ilarb., p. !15, PI. 11, Figs. 5-7. 



Obelia commixxuralis Agas.s. Cont. Nat. Hist. U. S., IV. pp. 315, 351, Pis. 33 (hoh Fig. 2), 34, 



Figs. 10-21. 1862. 

 Obelia comm'issuralis A. Agass. Proc. Bost. Soc. Nat. Hist., IX. p. 91, Fig. 5. 

 Laomedea dicholoma Leidy (non Auct.). Mar. Inv. N. J. and II. I., p. 6, PI. XI. Fig. 3G. 1855. 

 Laomedea gelatinosa Stimps. {iwn Auct.). Mar. Inv. Grand Manan, p. 8. 1853. 

 Laomedea gelalinosa Gould. Rep. Inv. Mass.' Bay, p. 350. 1841. 



The Obelia commissuraUs of McCrady, which extends from Charleston 

 to the coast of New England, and even as far as Grand Manan, has an 

 exceedingly slender polypidon and Ki„. 134. 



branches very profusely ; the branches, 

 stretching m graceful curves on both 

 sides of the main stem, reach their 

 greatest length about midway, and 

 then taper very gradually towards the 

 upper extremity. It can at once be 

 distinguished on account of its pecu- 

 liar mode of growth ; it attains from 

 five to six and even seven inches in 

 length. At the time when it bears 

 reproductive calycles, it is still more 

 easily distinguished from the allied 

 species by the shape of the calycles ; 



they are slender, conical, the base of the cone with its rounded ed 

 being surmounted l)y a short nock (Fig. 134) ; they bear from ten to 



Fi£c. 134. Porticjn (if stem of IIv<Ir:\rium of Olidia commissuralis. 



o-i's 



