OBELIA. 91 



Eucope ? divaricata A. Agass. 



Laomedea dicaricuta McCu. Gyinn. Cliarl. Harb., p. 93. 



An exainiiuitioii, by Professor Clark, of the reproductive calycles of 

 specimens collected at Charleston by Professor Agassiz, shows that the 

 Mediisa3 have forty-eight tentacles. The Hydrarium is closely related 

 to that of the Eucope i^iiriformis, which, together with the present 

 species, will 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 P^R. et Les. ; in Ann. du Mus., XIV. p. 43. 1809. 

 Obelia Ag.\ss. Cont. Nat. Hist. U. S., IV. p. 361. 1862. 

 Obelia McCr. Gymn. Cliarl. Harb., p. 94, 



Obelia cornmissuralis McCr. 



Obelia cominhmralis IMcCr. GjTnn. Charl. Harb., p. 95, PI. 11, Figs. 5-7. 



Obelia cornmissuralis Agass. Cont. Nat. Hist. U. S., IV. pp. 315, 351, Pis. 33 (tion Fig. 2), 34,' 



Figs. 10-21. 1862. 

 Obelia cornmissuralis A. Agass. Proc. Bost. Soc. Nat. Hist., IX. p. 91, Fig. 5. 

 Laomedea dichotoma Leidy {non Auct.). Mar. Inv. N. J. and R. I., p. 6, PI. XI. Fig. 36. 1855. 

 Laomedea gelatinosa Stimps. (non Auct.). Mar. Inv. Grand Manan, p. 8. 1853. 

 Laomedea gelatinosa Gould. Rep. Inv. Mass. Bay, p. 350. 1841. 



The Obelia commissuralis 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 Fip. i34. 



branches very profusely ; the branches, 

 stretching in graceful curves on both 

 sides of the main stem, reach their 

 greatest length al^out 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 edges 

 being surmounted by a short neck (Fig. 134) ; they bear from ten to 



Fig. 134. Portion of stem of Hydrarium of Obelia commissuralis. 



