340 POLYZOA INFITNDIBULATA. 



cimen when dried assumed only a very faint ash-colour, very dif- 

 ferent from the much deeper ash-colour in all the dried specimens of 

 Flustra avicularis I have seen." Professor J. Reid. 



Van Bene den has assumed this species as the type of the genus 

 Cellularia. He has given a very minute anatomy of its bird's-head 

 processes. The polype has fourteen tentacula, and the aperture at 

 which it issues from the cell is very large and without a distinct 

 rim. 



* * * * Apertures lateral and very large. 



7. C. NERiTiNA, " cells quadrangular^ lengthened^ loith a 

 truncated summit^ the outer angle projecting.'"'' Miss Black- 

 burn e. 



Plate LX. Fig. S, 4. 



Remarkable Coralline, Ellis in Phil. Trans, abridg. x. 345, pi. 8, fig. a A.-G. Ellis 

 Corall. 35, pi. 19. — Sertularia neritina, Lin. Syst. 1315. D. Chiaie Anim. s. vert. 

 Nap. iv. 147. Esper Sert. tab. 13, fig. 1-3. — Cellularia neritina, Pall. Elench. 67. 

 Flem. Brit. Anim. 539. — Cellaria neritina, EUis and Solund. Zooph. 22. Lam. 

 Anim. s. vert. 2de edit. ii. 1 90. — Acamarchis neritina, Lamour. Corall. 58, pi. 3. 

 fig. 2. Risso L'Eui-op. merid. v. 318. Blainv. Actin. 459, pi. 77, fig. 3. 



Hah. On the English coast, rare. " I possess a specimen from 

 the collection of the late Dr. Walker, which he received from Miss 

 Blackburne from the coast of Cheshire," Fleming. Scarborough, 

 very rare, W. Bean. Tynemouth, Miss Ellen Forster. Dredged 

 from thirty-five fathoms, Copinstra, Lieut. W. L. Thomas, R.N. 



Poly2Didom several inches in height, or growing in confervoid 

 spreading tufts, almost membranous, of a white or brownish colour, 

 bushy, dichotomously divided, the segments narrow-linear, subcylin- 

 drical, composed of a double series of semialternating cells divided 

 by a waved septum ; cells contiguous throughout, oblong, elongate, 

 with smooth semitransparent parietes, truncate above, the outer 

 angle projecting into a very short spine ; aperture large, oval, with a 

 smooth margin : ovarian capsules pearly, subsessile, globular, or 

 rather formed like the young shells of a Nerite, for which they were 

 at one time mistaken by Ellis. 



Polypidoms are occasionally to be found without a single nerite- 

 like operculum upon them. The branches of these are more slender 

 than the fruitful specimens. 



Cellularia neritina is recorded as an Irish species on the authority 

 of Mr. Templeton, who is said to have found it in Belfast Lough 

 and in Dublin Bay. Loudon's Mag. Nat. Hist, ix. 4G9. The 



