302 POLYZOA LVFUNDIBULATA. 



sea-weeds it is plentiful on the coast of Cornwall, whence I have 

 many specimens from C. W. Peach, (y.) On Sertularia operculata 

 from south coast of Isle of Wight, W. Thompson. 



Attached to sea-weeds, in small circular or oblong or irregular 

 crusts, by a very thin filmy or calcareous basis in which the cells are 

 partially immersed. Cells radiating in rows, sometimes irregular, 

 semialternate, subcylindrical, or elliptical, raised towards the oral 

 end, smooth and hyaline, marked with one or two slight folds, the 

 walls being almost membranous ; the aperture round, entire, some- 

 what contracted, with a narrow plain rim. In the majority of speci- 

 mens the central cells are hidden more or less completely with the 

 ovarian capsules, which are comparatively very large, globular, and 

 vitreous, roughened with a few granules, and perforated on the 

 inner or posterior side by a small circular opening. These capsules 

 have been mistaken for cells, and are, in fact, sometimes so numerous 

 as entirely to obliterate or conceal them. 



The variety /3 differs from the normal specimens in nothing ex- 

 cept the greater thickness and opacity of the cells. In y, which is 

 undoubtedly the Cellepora ovoidea of Lamouroux, the cells are not 

 arranged in regular series, but have a tendency to heaping, hence 

 it occurs in little calcareous clusters of an irregular shape. The 

 specimens which I have from W. Thompson are parasitical on Ser- 

 tularia operculata, and I feel disposed to attribute the conglomera- 

 tion of the cells to the narrow site hindering the free development of 

 the species. It was first collected by Mr. Thompson, in Belfast Bay, in 

 1835. " I have since obtained it," he says, "from Strangford Lough 

 and other localities on the Irish coast, around which it is probably 

 found. I have no doubt that it is generally passed over as the 

 young state of some larger species. I find it on algag as well as on 

 zoophytes." 



Linnaeus, in his description, has had the ovarian capsules solely in 

 view. The description of Otho Fabricius is, on the contrary, re- 

 markably characteristic, but, regarding the ovaries as cells, he has 

 erroneously adopted the Linnaean specific character : " Cellepora cel- 

 lulis subglobosis diaphanis, ore obliquo simplici." The description 

 is as follows : " Stratum album diaphanum, verrucosum, polymor- 

 phum, jam suborbiculare, jam cylindricum, jam convexum, jamque 

 planum, respectu corporum, quibus adnatum est. Cellulas confertse 

 bimorphse, quse enim discum occupant cumulatae, subglobosse orificio 

 obliquo, medio, laterali, vel etiam terminali infero fere condito, 

 variant ; margini autem propriores subcylindricae, jacentes, ore 



