CELLULAEIA. 341 



the base of some of the cells there arises a long setaceous 

 bristle, that bends over the upper surface of the polypidom, 

 and it is moveable. We doubt not that this formidable 

 lash is to keep off intruders, and to sweep them away when 

 they have made encroachments. 



*** Apertures superior and' very large. 



6. CELLULARIA AVICULARIA, BirdVhead Coralline, Ellis. 

 (Plate XIX. fig. 72.) 



Hab. On corallines in deep water. Salcombe, common, 

 Eev. T. Hincks ; Peterhead, Mr. Peach. 



The polypidom is erect, bushy, greyish-white. The cells 

 have a spine at each of the upper angles, and the aperture 

 is generally covered with a round pearly operculum. " On 

 the outside of each cell we discover the appearance of a 

 bird's head, with a crooked beak, opening very wide." 

 (Ellis.} It is distinguished from Flustra avicularis by 

 having two conical spines at the angles, whereas it (F. avi- 

 milaris] has four, which also differ in appearance. The colour, 

 likewise, is fainter when dried. I have it from Mr. Tuma- 

 nowicz, Hastings. 



*#-** Apertures lateral and very large. 



7. CELLULARIA NERITINA, Miss Blackburne. 



Hab. " Miss Blackburne, Cheshire," Dr. Fleming; Scar- 



