CELLEPORID.E : MEMBRANIPORA. 327 



genus will become necessary ; and I have to remark that the sections 

 into which I have thrown the species are quite artificial. They may, 

 perhaps, he more naturally arranged under three sections as follows : 

 I. Cells laid on a thin basilar circumscribed crust : L. hyalina, 

 tenuis, assimilis, granifera, and Landsborovii. II. Cells complete, 

 simply aggregate, not circumscribed : L. Hassallii, simplex, ventri- 

 cosa, Hyndmanni, ansata, ciliata, spinifera, annulata, figularis, bi- 

 foris, Peachii, Ballii, pertusa, punctata, ovalis, pediostoma, verrucosa, 

 and unicornis. III. Cells confluent, forming a crust in which they 

 are more or less immersed, the margin of the crust unfinished or 

 marked with lines which are the commencement of new cells : L. 

 auriculata, linearis, coccinea, trispinosa, immersa, and violacea. 



14. MEMBRANIPORA,* Blainville. 



CHARACTER. Polypidom encrusting, memlrano- calcareous, 

 spreading irregularly, formed of a single layer of alternating 

 approximated cells ; cells oval, horizontal, membranous, the 

 aperture patulous with a hard calcareous rim. 



1. M. PILOSA, aperture of the cell with one long hair and 

 several spinous denticles. Ellis. 



PLATE LVI. FIG. 6. 



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

 Pall. Elench. 50. Flustra pilosa, Lin. Syst. 1301. Mull. ZooL Dan. prod. 253. 

 Ellis and Soland. Zooph. 13. Esper Pflanz. Flust. tab. 4. fig. 1, 2. Berk. Syn. 

 i. 214. Lam. Anim. s. vert. ii. 159 : 2de dit. ii. 224. Grant in Edin. New Phil. 

 Journ. iii. 111. Flem. Brit. Anim. 537. Risso L'Europ. Merid. v. 335. Johnston 

 in Trans. Newc. Soc. ii. 265. pi. 9. fig. 5. Lister in Phil. Trans, an. 1834, 384, 

 pi. 12. fig. 2. Templeton in Mag. Nat. Hist. ix. 469. Membranipora pilosa, 

 Johns. Brit. Zooph. 280. pi. 34. fig. 10-12. Couch Corn. Faun. iii. 119. Van 

 Beneden Recherch. 53. pi. 7. fig. 1-10. 



Var. a. Polypidom assuming a stellate form. Membranipora stellata, W. TJiompson 

 in Ann. Nat Hist. v. 101. Hassall in Ann. and Mag. N. Hist, vii., 369. 



Var. /3. The long bristle abortive or destroyed. Ellis Corall. pi. 29. fig. D. Ellis in 

 Phil. Trans, abridg. x. 492. pi. 12. fig. 4. D. Flustra dentata, Ellis and Soland. 

 Zooph. 15. Turt. Brit. Faun. 209. Lam. Anim. s. vert. ii. 158 : 2de edit. ii. 224. 

 Templeton loc. s. cit. 469. Flustra lineata, Esper Pflanz. Flust. tab. 6 Membra- 

 nipora pilosa, Farre in Phil. Trans, an. 1837, 412, pi. 27, fig. 1-5. 

 Hob. On the Laminariae and lesser sea-weeds most abundant, and 



not uncommon on old shells. 



Polypidom incrusting, membrano-calcareous, irregular, following 



the shape and form of the objects it grows upon, straw-yellow, thick- 



From membrana, a thin skin or film, and -rropOQ. 



