50 ZOOPHYTES. 



When in this transient passage, the under seemed different from the 

 upper surface. Great disparity of size was sensible. The motion of some 

 was continued to the third day ; but most of them were quiescent in 

 twenty-four hours. — Figs. 2, 3, magnified. 



These are singular facts, rarely seen among the zoophytes. They seem 

 peculiar to the ascidian hydra, denoting the relation, though remote, be- 

 tween the Flustra hispida, the Alcyonium, and the Botryllus. 



All the larger Alcyonia which I have had an opportunity of inspect- 

 ing were founded on solid substances, which rather argues that they rise 

 vertically. I have seen but small specimens connected with sponges, fis- 

 tulous corallines, and the like ; and even when apparently in a very early 

 stage, they are rooted on the outside or the inside of shells. 



Perhaps they abound in the recesses or cavities of rocky places, for 

 great profusion of some kinds have reached me occasionally from the crab 

 fishers. 



The following conclusions may be deduced from the preceding obser- 

 vations on the Alcyonium gelatinosum, and immediate congenera: — 



I. The Alcyonium gelatinosum is a massy, solid, compact product. 



II. It rises above two feet from a very contracted root or founda- 

 tion. 



III. Its form is extremely various, rounded, ramified, or wholly flat- 

 tened. 



IV. The surface is entirely overspread with cells containing hydra;. 



V. The adult hydrse are provided with from 12 to 18 tentacula. 



VI. The Alcyonium propagates by ciliated gemmules, which, after 

 great activity, become stationary. 



VII. After an interval ranging between nine and twelve days from 

 production, a hydra originates from the stationary gemmule, and next an- 

 other hydra or cell from the side of the cell of the first. 



Plate XII. Alcyonium gelatinosum. Specimen twenty-four inches and a half 

 high. Reduced. 

 XIII. Another specimen. 



