76 ZOOPHYTES. 



Other specimens seemed to correspond with the preceding conforma- 

 tion ; all apparently diffusing from an original central point. 



The aspect of the circumference indicates that increment ensues 

 after the fashion witnessed in the Flustra. New cells are preparing on 

 the exterior of fig. 5, a, b. 



The direction of the cells shewed that there was much correspon- 

 dence between the generation and evolution of the hydrsc with those of 

 the Alcyonidium mytili, as betrayed by the advancing embryo of the latter. 



This product is rare, nor have I been able to procure it alive. But 

 the subject is introduced principally to evince that its enlargement is pro- 

 bably by diffusion around an original cell. 



All those occurring to me have been seated on mussel and oyster shells. 



In three months, the specimen represented became white as snow, 

 and penetrated by numerous minute punctures. 



Plate XXIV. Fig. 1. Lepralia pustula. 



2. The same enlarged. 



3. Cells, profile. 



4. Cells with a serrate circle environing the base. 



5. Portion of the circumference of figs. 1, 2. 



All the figures, except the first, are enlarged. 



(2.) Lepralia Edentata. — Toothless Sea Scurf . — Plate XXV. Fig. 1. 

 — A specimen of this Lepralia spread irregularly as a white crust on an old 

 oyster shell, and turned over the edge, in which respect the genus re- 

 sembles some of the Flustra?. It was composed of cells, apparently smooth, 

 and without teeth ; of unequal dimensions, nor of true elliptical or ovoidal 

 form, though seemingly oval. The cells were not arranged in reciprocal 

 order. Pale grey, very lively, ascidian hydrae, with about twelve tentacula, 

 occupied them. 



Plate XXV. Fig. 1. Lepralia edentata, portion with hydra; enlarged. 



No suitable representation after nature is admitted by many of such 

 diffusing products. They cannot be rendered intelligible. 



