﻿April, 1857.] elliott society. 135 



me to say that I have not seen the actual separation of a bud from 

 the Hydroid, and its assumption of the form of figure 5. My con- 

 fidence that they are one and the same, is due to the very marked 

 and almost unmistakeable peculiarities of the Medusa, which are 

 plainly exhibited in the buds while attached to their hydra. To 

 my former Master in Science, Professor Agassiz, to whom America 

 owes the only special publication on her Medusae, I inscribe this 

 remarkable species. 



DIPURENA, nov. gen. 

 General form rather conical; digestive trunk elongate, and divi- 

 ded into two cavities, one above and the other below, connected 

 with each other and with the small quadrate chamber at the origin 

 of the radiate tubes, each by a delicate slender tube ; sexual, glands 

 arranged in two masses, one surrounding the upper and the other 

 the lower digestive cavity, separated by a constriction; tentacula 

 four, clavate, tubular, attached at the disk margin to colored bulbs, 

 each of which bears an ocellus. This genus differs from SJabberia 

 in the position of its sexual glands — and from Sarsia by its clavate 

 tentacula, and the division of its sexual gland into two portions. 



Remark.. — This genus is certainly a remarkable one, on ac- 

 count of the number of chambers or sinuses in the course of the 

 nutrient circulation. First the digestive cavity itself appears to be 

 divided into an upper and lower cavity, besides which there is a 

 separate chamber at the intersection of the radiate tubes as in 

 Sarsia, then each of the marginal bulbs must be counted in this 

 category as in Sarsia, to which in this genus appear to be added 

 four other chambers in the terminal bulbs of the tentacula, mak- 

 ing in all eleven chambers in the course of the digestive and cir- 

 culatory systems. 



Distribution. Charleston Harbor. 



DIPURENA STRANGULATA, nov spec. 

 PI. 8, Ff. 1-2. 



General form of the disk ovoid, truncated below, of considerable 

 thickness above the insertion of the digestive trunk, its outline 

 converging above to a rather pointed apex. The four radiating 

 tubes, very faint in outline, being indeed scarcely visible. The 

 chamber into which they open at the base of the digestive trunk is 

 quite distinct, separated from the digestive cavity by a constric- 

 tion, and with a lake colored nucleus. Digestive trunk incapable 

 of retraction within the bell. The constriction occurs about one 



