286 
Z. ASCIDIOIDA. 
Flustra. 
Vers, iii. 141. Corail. 45. Flem. Brit. Anim. 535. Hogg's Stock. 36. 
Grant in Edin. New Phil. Journ. iii, 111. Stark, Elem. ii. 437. John- 
ston in Trans. Newc- Soc. ii. 264, pi. 9, fig. 4. Templeton ut. sup. eit. 
469. JRoget, Bridgew. Treat- i. 165, fig. 63, 64; and 172, fig. 69, 70. 
Dalyell in Edin. New Phil. Journ. xvii. 413 ; and in Rep. Brit. Assoc, 
an. 1834, 603. La F. voile, JBlainv. Actinolog. 451. 
Hah. On shells from deep water. From Aberdeen, Skene. 
Leith shore, Mr Parsons. Not unfrequent at Seaton, Hartlepool, 
Whitburn, and other places on the coast of Durham, J. Hogg. Coast 
of Berwickshire, not uncommon, G. J. Ireland, Templeton. 
Polypidom frondose, fixed by a small disk, narrow at the base with 
thickened margins, dilating- upwards and becoming- very broad in 
proportion to the height, which at most is about two inches, thin, 
yellowish brown, deeply divided, the segments broad and somewhat 
rounded on the apex. Cells on one side only, large, and smooth. 
Polypes with about 22 tentacula, which are “ nearly a third of the 
length of the body, and there appear to be about 50 ciliae on each 
side of a tentaculum, making 2200 ciliae on each polypus. In this 
species there are more than 18 cells in a square line, or 1800 in a 
square inch of surface, and the branches of an ordinary specimen pre- 
sent about 10 square inches of surface ; so that a common specimen 
of the F. carbasea presents more than 18,000 polypi, 396,000 tenta- 
cula, and 39,600,000 ciliae.” Grant. 
5. F. setacea, cells in 2 or S rows , oval , with a setaceous 
bristle . Rev. Dr Fleming. 
Flustra Ellisii, Fleming in Wern. Mem. ii. 251, pi. 17, fig. 1 — 3 
F. setacea, Flem. Brit. Anim. 536 La F. setacee, Blainv. Actinolog. 
451. 
Hab. “ Along with Cellepora cervicornis, from deep water, Zet- 
land,” Dr Fleming. 
“ Height nearly two inches ; branches linear, not the tenth of an 
inch in diameter ; substance firm, brittle ; the base consists of small 
tubes, which by their union, form the branches, dorsally carinated 
by the union of the tubes, which, diverging to each side and dividing 
form two denticles and a long bristle, the latter serrated on one side ; 
cells oblique.” Dr Fleming. 
6. F. avicularis, cells in 4 or jive rows , oblong , with a strong 
conical spine at each side of the aperture . J. Ellis. 
Plate xxxvi. Fig. 3, 4. 
Corallina cum appendiculis lateralibus avium capitum forma, Ellis, Corail. 
pi. 38, fig. 7. Cellularia avicularia 0, Pall. Elench. 68. Flustra 
avicularis, Soverby Brit. Misc. ii. 21. pi. 71. Turt. Brit. Faun. 210. 
Flem. Brit. Anim. 536. Johnston in Trans. Newc. Soc. ii. 265 La 
