536 ZOOPHYTA. FLUSTRAD^. Flustra. 



absence of prominent denticles on the walls of the cells ; dorsal surface glossy. 

 Body of the animal cylindrical, head subglobular, surrounded by twenty -two 

 tentacula of nearly equal thickness throughout, and about one-third of the 



length of the body. Ova produced singly in the cells, ovate and ciliated 



See a valuable paper by Dr Grant on the history of this species, in the Edin- 

 burgh New Philosophical Journal. 



143. F. setacea. — Dichotomously divided, rounded dorsally, 

 the face with two or three rows of oval cells, having a setaceous 

 notched tooth. 



F. Ellisii, Flem. Wern. Mem. ii. 251. t. xvii. f. 1 Along with Cellepora 



cervicomis, from deep water, Zetland. 



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. 



144. F. avicularis. — Dichotomously divided, flat, thin ; cells 



in two, three, four, or five rows, with spines at the end. 



Corallina cum appendiculis lateralibus avium capitum forma, Ellis, Coral. 



t. xx. f. 2., and t. xxxviii. f. "].— Sertularia av. Linn. Syst. i. 1315 



Cellularia av. Pall. EL G8.— F. av. Sower. Brit. Misc. t. lxxi. Cellaria 



av. and Flustra angustiloba, Lamk. Hist. ii. 141. and 158 Crisia av. 



and flustroides, Lamour. Cor. Flex. 141 — On various parts of the coast. 



Height upwards of an inch ; leaves narrow, slightly truncated ; back 

 smooth ; sides denticulated with appendages from the middle of the cells, 

 nearly resembling a parrot's head and bill, the rudiments of tubular proces- 

 ses ; cells quadrangular, lengthened, with produced spinous processes at the 

 sides or summit. In its young and most slender condition it has only two rows 

 of alternate cells, in which state it has been considered a Cellaria ; but, in 

 the same branch we have observed the cells in two, three, or four rows. It 

 is not rare in the Frith of Forth, and it likewise occurs in the Zetland seas. 





Spreading, adnate. 



145. F. mcmbranacea. — Expansion with the margin undi- 

 vided; cells quadrangular, lengthened, with spinous processes 

 at the angles. 



Linn. Syst. i. 1301. Sol. Ellis, Zooph. 18 — On broad-leaved fuci, com- 

 mon. 



Encrusting uniformly the surface; rough; cells linear; the processes at 

 the angles are blunt, and not equal to the breadth of the cell. 



1 46. F. unicornis. — Expansion with the margin divided ; 

 cells ovate or subquadrangular, with a blunt hollow conical pro- 

 cess at the summit of each. 



F. membranacea, Mull. Zool. Dan. t. cxvii. f. 1, 2. — F. un. Flem. Edin. 

 Phil. Journ. ii. 87 — Common, especially on stones, near low water- 

 mark. 

 The margins of the cells are a little thickened ; the cells themselves are 

 shorter and wider than the preceding species, with which it has hitherto beeu 

 confounded. 



