BRYOZOA FROM ZANZIBAR. 523 



is a pair of the minute aviciilaria at the si<le of the zooeciuin 

 to which I referred in my lieport of the Sudanese Bryozoa, but 

 none were found in H. bispinata. Further, the operculum of 

 H. albirosli-is has a muscular ridge turning sharply inwards and 

 ending off sliort, whereas the operculum of H. bispinata has a 

 ridge, very thick at the base, extending as a thin band nearly to 

 the apex. U. albirostris has a veiy long oral gland nearly the 

 length of the polypide, while the gland of S. bispinata, though 

 also cylindrical, is much smaller. 



Loc. Florida, 25-35 fath. (Sm.) ; Heard Island, 35 fath. (ChalL); 

 New South Wales [IVaters); Victoria (2IacG.) ; Amirante, 12-18 

 inth. (I'korneli/). Wasin, B. East Africa, 10 fath. (501); Ohuaka, 

 Zanzibar, 3 fath. (525), collected by Crossland. 



Fossil. Australia, N. Zealand (11^) ; Victoria [31acG.). 



MiCEOPORELLA CILIATA Pallas. 



Loc. ISTorthex-n Seas ; British ; Atlantic ; Mediterranean ; Red 

 Sea ; Ceylon ; Australasia and varieties in Japan, Australasia ; 

 Zanzibar (ff.), the IST. Indian Ocean. Wasin, Brit. E. Africa, 10 

 fath. (500), collected by Crossland. 



Fossil. Pliocene and Miocene of Europe, and Tertiary of 

 Australia and New Zealand. 



Rhynchozoox profundum, var. laminatum, nov. (PI. LXXII. 

 fig. 11.) 



The specimens from Wasin may be the i?. j)'>'ofundu'm as first 

 described by MacGillivray, but it is not the profundum of the 

 Prodromus, which MacGillivray considers is the same as R. longi- 

 rostre Hincks. 



The species of Rhynchozoon are difficult to distinguish, but the 

 ovicell has a lamina in the front like the lamina of Retepora, to 

 which it is related, and the shape of the lamina furnishes specific 

 characters of value. In this Zanzibar variety the lamina is long 

 and rounded at the end, whereas in R. profimdtiin it is shorter, 

 very broad, and spreads out at each side. In R. bisjnnosum Johns, 

 it is quite short. 



In this variety as in R. pi'ofundum the denticle is broad and 

 uncinate, and the ovicell is but little raised above the general 

 surface. There are narrow pointed avicularia over the surface, 

 as usual in Rhynchozoon. 



Loc. Wasin, Brit. East Africa, 10 fath, (520), collected by 

 Crossland. Noumea (in A. W. W. coll.), 



Retepora hirsuta Busk. 



Reiepora hirsuta Busk, Zool. Chall. Exp, vol. x. p, 119, pl.xxvi. 

 fig. 4 (1884) ; Waters, " Mar. Biol, of the Sudanese Red Sea," 

 Journ. Linn. Soc, Zool. vol. xxxi. p. 175, pi, xviii, figs. 24-26 

 (1909), 



Specimens from (500) and (520), which are undoubtedly the 



