174 ZOOPHYTOLOGY. 



The cells are disposed in longitudinal series, one above the 

 other — but alternate with each other in the contiguous series. 

 The mouth of the cell is contracted, circular, and simple. 



On a New Species of Bugula. By Joshua Alder, Esq. 



Bugula turbiiiata, PI. XVII, figs. 1 — 4. 



Polyzoary orange-coloured or yellowish, paler when dry ; one to two 

 inches high, forming an ascending spiral, the branches dividing dichoto- 

 mously, truncated at top, and arching outwards. Cells in two to five series, 

 elongated, the aperture reaching nearly to the bottom; a single erect 

 spine at each upper angle. Avicularia of two sizes, those on the outside 

 moderately large, with a rounded head, and a short back abruptly bent at 

 the point ; situated on the upper part of the margin of the cell ; inner 

 avicularia small. Ovicapsules subglobose, with a rim rising into a peak in 

 front. 



Cellularia avicularia, Pallas, 'Elencli. Zooph.,' 68 (?). 



Gosse, 'Ramb. Dev. Coast.,' p. 195, t. x. 



This species has hitherto been confounded with Bu- 

 gula avicularia, to which it bears a strong resemblance, 

 but is nevertheless quite distinct. In its mode of growth it 

 is rather more robust than that species, and may readily be 

 distinguished from it by the number of cells increasing to 

 three, or occasionally even to five longitudinal rows in some 

 of the branches ; in B. avicularia, there are never more than 

 two tliroughout. On examining the two kinds microscopi- 

 cally, other differences are found. The cells in B. turbinata 

 have invariably only a single large spine on the outer angle ; 

 B, avicularia has two spines, as correctly represented by 

 Professor Busk,^ though the smaller one has been frequently 

 overlooked. The avicularium is rather smaller in B. turbi- 

 nata than in B. avicularia, and has the head more rounded, 

 and the beak much shorter and more abruptly bent at the 

 point (fig. 4). It is also set higher up on the margin of 

 the cell, frequently close below the spine. The ovicapsule 

 in this species is smaller, and has a border generally rising 

 into a peak in front. 



The only published figure of this species that can ])c re- 

 cognised with certainty is that of Mr. Gosse, in his inte- 

 resting ' Rambles on the Devonshire Coast,' where it is well 

 described under the name of Cellularia avicularia. The 

 magnified figures g, h, pi. xxxviii of Ellis's ' Corallines,' 

 would seem to represent this species, having only a single 



* ' Catalogue of jMarinc Polyzoa,' \>\. liii. 



