OBELIA. 91 



Eucope ? divaricata A. Agass. 



Laomedea divaricata McCn. Gymn. Charl. Harb., p. 93. 



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

 specimens collected at Charleston by Professor Agassiz, shows that the 

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

 to that of the Eucope pyriformis, which, together with the j)resent 

 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. 



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

 Ohdia Agass. Cont. Nat. Hist. U. S., IV. p. 351. 1862. 

 Obdia McCk. Gymn. Cliarl. Harb., p. 94. 



Obelia commissuralis McCe. 



Gbelia commissuralis McCr. Gyinn. Charl. Harb., p. 95, PI. 11, Figs. 5-7. 



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



Figs. 10-21. 1862. 

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

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

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

 Laomedea gelaiinosa Gov LV. Kep. Inv. Mass. Bay, p. 350. 1841. 



The Ohelia 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 Fig. isi. 



branches very profusely ; the branches, 

 stretching in 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 edges 

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



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



