78 ZOOPHYTES. 



the whole of those of the margin. Though kept a long time, nothing re- 

 sulted from them. 



More satisfactory inspection of such Lepralise is obtained by moderate 

 magnifiers, than by those of higher powers. 



Plate XXV. Fig. 6. Lepralia lineata. Portion enlarged. 



(6.) Lepralia Margarita. — Plate XXV. Figs. 7, 8, 9, 10, 11, 12. — 

 Under a lens, this species resembles so many rows of pearls. It is pure 

 white ; but not of any definite form. 



The surface of a patch is composed entirely of irregular cells, with a 

 wide orifice, guarded by one or two spines. 



Many of the cells contain a large orange spherule. 



This Lepralia invests mussel shells. 



Plate XXV. Fig. 7. Lepralia marcjarita on a mussel shell. 



8. Part of the same, enlarged. 



9. Another specimen. 



10. Part of the same, enlarged. 



11. Corpusculum or gemmule, apparently mature, in one of t he- 



cells, enlarged. 



12. Another. 



(7.) Lepralia spinosa. — Plate XXVI. Figs. 1, 2. — A. specimen 

 occurring to me might have been contained in a rude quadrangle, eash side 

 extending about five lines. The surface rose in slight convexity, but the 

 thickness of the Lepralia, a mere scurf, did not exceed the depth of a single 

 cell. The whole was distinguished by a reddish-purple colour. 



The surface of this species is composed entirely of cells, interspersed 

 with spines, one of these probably rising from the base of each. 



The cells have a circular orifice. 



Apparently the specimen had diffused on a shell originally, and spread 

 over some depressed or adhering stalks of the Titbidaria indivisa. 



Plate XXVI. Fig. J. Lepralia spinosa. 

 2. Portion enlarged. 



