﻿April, 1857.] 



ELLIOTT SOCIETY. 



167 



coiled threads of the greater thread-cell nodes of some of the Si- 

 phonoporae figured by Kolliker. (See Schwimmpolypen von Mes- 

 sina, pi. 5, ff. 2-3.) I did not observe any organic connection, how- 

 ever between this thread and the polyp — nor did it exhibit any 

 motions, nor appear to be ciliated. I do not venture to offer an 

 explanation, having never observed anything of the kind before 

 or since. 



The branching polypidom of this Eudendrium, torn from its 

 moorings, is frequently thrown up by the waves on the beach of Sul- 

 livan's Island, especially during the winter months. It is usually 

 denuded of its polyps, but I have had them reproduced from the 

 stem, in a jar of salt-water — as Dalyell relates of Tubularia as well 

 as Eudendrium, and as I have also observed in that genus. I have 

 never been so fortunate as to obtain a specimen with medusa-buds. 



This species grows below low-water mark, and is always rare, 

 but especially so in summer. 



I have, on one occasion, found a single denuded but compara- 

 tively robust polypidom, whose general appearance was so much 

 that of E. rameum, as to make it probable, that either this or a 

 nearly allied species is an inhabitant of our harbor. I have also 

 once found twining among algae a small creeping polypidom, 

 whose polyp's expanded base, and few and apparently contractile 

 tentacula, make it probable that a species like Van Beneden's E. 

 ramosa (Corydendrium Dana.) is also found here. 



HYDRACTINIA. Van Beneden. 



This genus preserves the form of a community. The Medusa 

 does not become free, and attains but a very low r stage of devel- 

 opment. There is no distinction, that I can find, between the disk 

 and the wall of the sexual organ; the males and females appear 

 to reside in distinct communities. The sexual contents of the 

 female ovary divides sometimes into several embryos. 



The polyps, according to Van Beneden are from the first pro- 

 vided with but a single whorl of tentacula. These in the adult are 

 cylindrical, (not clavate, nor pointed,) and very contractile. The 

 polypidom is horny and covered with spines. It is neither den- 

 dritic nor climbing, but incrusting, and protecting only the base 

 of each polyp. The medusa-buds are developed on clavate stems 

 which are polyps, modified in form for the fulfillment of this 

 function. 



The two forms described by Van Beneden, from the coast of 



