280 Z. ASCIDIOIDA. Membranipora. 



5. L. TRispiNOSA, cells radiating from a centre^ the aperture 

 armed below with 3 lonp spines. G. J. 



Platk xxxiv. Fig. 5. 



Discopora trispinosa, Johnston, in Edin. Phil. Journ. xiii. 222 Bere- 



nicea trispinosa, Johnston, in Trans. Newc. Soc. ii. 268. 



Hob. On shells from deep water, rare. Berwick Bay. 



Crust thin, circular, adherent, yellowish, or of a silvery white co- 

 lour with minute yellow dots : cells in rows radiating from the cen- 

 tre, horizontal, immersed, the apertures raised, round, cleft, but not 

 deeply, above, and belov/' armed with three spines of which the mid- 

 dle one is the longest. — The margin of the crust is a thin pellicle 

 marked with the raised lines which are to form the partitions between 

 the future cells. 



6. L. IMMERSA, crust Spreading irregularly^ the cells immersed 

 with small round apertures^ having a tooth on the proximal and 

 several spines on the distal margin. Fleming. 



Plate xxxiv. Fig. 8. 



Bereniceaimmersa, F/em. Brit. Anim. 533 B. flava, Johnston, in Trans. 



Newc. Soc. ii. 268 La B. immergee, JBlainv. Actinolog. 445. 



Hab. On stones and shells from deep water, frequent. 



Crust rather thick, spreading irregularly, ochre-yellow, or some- 

 times cream-yellow, roughish and punctured to the naked eye by the 

 apertures of the cells which do not radiate from a centre, though ar- 

 ranged in regular series. They are immersed in the crust so that 

 their divisions are indistinct ; the apertures contracted with a tooth 

 on the upper edge and several spines on the lower margin which are 

 very brittle and liable to be broken off, but when entire are longer 

 than the diameter of the cell. 



34. Membranipora,* Blainville. 

 Character. Polypidom encrusting, membrano-calcareous, 

 spreading irregularly, formed of a single layer of alternating ap- 

 proximated cells; cells oval, horizontal, membranous, the aper- 

 ture ■patulous with a hard calcareous rim. — Polypes as'cidian. 



1. M. PI LOS A, aperture of the cells with one long hair and se- 

 veral spinous denticles. J. Ellis. 



Plate xxxiv. Fig. 10-12. 

 Irregular spongy foliaceous Coralline, Ellis, Corall. 73, no. 4, pi. 31. 



* From membrana — a thin skin or film, and Trepm. 



