280 
Z. ASCIDIOIDA. 
Membranipora. 
5. L. trispinosa, cells radiating from a centre , the aperture 
armed below with 3 long spines . G. J. 
Plate xxxiv. Fig. 5. 
Discopora trispinosa, Johnston, in Edin. Phil. Journ. xiii. 222. Bere- 
nicea trispinosa, Johnston, in Trans. Newc. Soc. ii. 268. 
Hab. 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 below 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. 
Berenicea immersa, Flem. Brit. Anim. 533.' B. flava, Johnston, in Trans. 
Newc. Soc. ii. 268. La B. immergee, Blainv. 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 wdien entire are longer 
than the diameter of the cell. 
34. Membranipora,* Blainville. 
Character. Polypidom encrusting , membrano-calcareous y 
spreading irregularly y formed of a single layer of alternating ap- 
proximated cells; cells oval , horizontal , membranous , the aper- 
ture patulous with a hard calcareous rim. — Polypes ascidian. 
1. M. pi los a, aperture of the cells with one long hair and se- 
veral spmoas 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 iropog. 
