CLYTIA BICOPIIORA. 79 



glands, extending towards the base of the proboscis. The Hydrarium 

 (see figure of Professor Agassiz in Vol. IV. PI. 29, Fig. 6) grows from 

 three quarters to an inch in height, in small tufts attached to Fucus ; the 

 calycles are strongly compressed (Fig. Ill), and differ as much in their 

 proportions as those of C. cylindrica, when seen from the broad or from 

 the narrow side. This species may yet prove identical with the Clytia 

 Johnstoni of Alder. According to the figure of Wright of the Medusa 

 of Campanularia Johnstoni, it can hardly be distinguished from the 

 Medusa of our Clytia bicophora ; the Medusa of C. volubilis figured by 

 Hincks resembles also closely our Clytia Medusse. The Medusa figured 

 by Dalyell as the young of M. Jimhriata, on PI. Fig.m. 



52, Fig. 4, Eare and Eemarkable Animals of 

 Scotland, is undoubtedly a young Medusa of C 

 Johnstoni, to judge from its characteristic attitude. 

 If the figure Avhich Gosse has given of the calycle 

 of this same species in his " Devonshire " is correct, 

 there can be but little question as to their specific 

 difference ; the pecuhar species figured by Gosse 

 has, however, not been noticed by other English 

 observers. The Medusse of Clytia cylindrica and 

 of Clytia bicojjhora are so alike, immediately after 

 their escape from the reproductive calycles, that 

 when the development of Clytia cylindrica was first discovered, the 

 Medusse which are here figured as Clytia hicoj^hora (Fig. 41, Agassiz's 

 Cont. Nat. Hist., p. 307) were mistaken for the adult of the Medusse of 

 Clytia cylindrica. As the Clytia hicojjhora is very common at Nahant, 

 the complete development of the Medusa has been traced, and the 

 error is here corrected. 



Eastport, Maine (W. Stimpson) ; Massachusetts Bay (Agassiz) ; Vine- 

 yard Sound and Naushon (L. and A. Agassiz). 



Cat. No. 133, Eastport, Maine, July, 1852, W. Stimpson. Hydrome- 

 dusarium. 



Cat. No. 134, Beverly, Mass., July, 1861, A. Agassiz. Hydrarium. 



Cat. No. 135, Vineyard Sound, July, 1849, L. Agassiz. Hydromedu- 

 sarium. 



Cat. No. 136, Grand Manan, August, 1857, J. E. Mills. Hydromedu- 

 sarium. 



Cat. No. 137, Nahant, Dec. 1855, H. J. Clark. Hydromedusarium. 



Cat. No. 154, Eastport, Maine, July, 1852, W. Stimpson. 



Cat. No. 401, Nahant, June, 1862, A. Agassiz, Hydromedusarium. 



Cat. No. 443, Nahant, June, 1864, A. Agassiz. Medusa. 



Museum diagram No. 17, after L. and A. Agassiz. 



Fig. 111. Sterile Hydra and reproductive calycle, seen from the broad side. 



