CLYTLA BICOPHORA. 79 



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

 (see figure of Professor Agassiz in \'oI. IV. PI. 2[), Fig. 6) grows from 

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

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

 proportions as those of C. ci/Uudrica, when seen from the broad or from 

 the narrow side. This species may yet prove identical with the Cli/tia 

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

 of Campwmlarla Johnstoni, it can hardly be distinguished from the 

 Medusa of our Cli/fia hkophora ; the Medusa of C. voluhUis figured by 

 Ilincks resembles also closely our Clytia Medusie. The Medusa hgured 

 by Dalyell as the young of M. Jimbriata, on PI. 

 62, Fig. 4, Rare and Remarkable Animals of 

 Scotland, is undoubtedly a young Medusa of C\ 

 Johnstoni, to judge from its characteristic attitude. 

 If the figure which 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 peculiar species figured by Gosse 

 has, however, not been noticed by other English 

 observers. The Medusas of Clytia cylindrica and 

 of Clytia hicojjhora are so alike, immediately after 

 their escape from the reproductive calycles, that 

 when the development of Clytia cylinch^ica was first discovered, tlie 

 Medusa) which are here figured as Clytia hico2:)hora (Fig. 41, Agassiz's 

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

 Clytia cylindrica. As the Clytia hico2^hora is very connnon 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, 1801, A. Agassiz. Hydrarinm. 



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. 



