BRYOZOA FROM ZANZIBAR. 513 



Cargados, 28 fath. Wasin, Brit. East Africa, 10 fath. (501); 

 Ras Osowamembe, Zanzibar Channel, 10 fath. (504, 514); Prison 

 Island, Zanzibar Channel (505) ; Chuaka Bay : collected by 

 Crossland. 



Smittina trispinosa, var. protecta Thornely. 



Smittia trispinosa, var. protecta I'hornely, Ceylon Pearl-Oyster 

 Fisheries, vol. iv. Polyzoa, p. 123 (1905); Waters, "Mar. Biol, 

 of the Sudanese Red Sea," Journ. Linn. Soc, Zool. vol. xxxi. 

 p. 173, pi. xvii. figs. 5, 6(1908). 



Smittia nitida Hincks, Ann. Mag. Nat. Hist. ser. 5, vol. vii. 

 p. 159, pi. ix. fig. 5 (1881). 



There are two specimens with the large avicularia situated 

 diagonally distal to the oral aperture. The ovicells of this vai-iety 

 and of typical nitida are similar, and there are some specimens 

 with a large, almost spinous, process at the proximal part of the 

 peristome, with a similar process on the ovicell just distal to the 

 area of pores. An identically similar form occuis off the Cape 

 Verde Islands, and Osbiirn * mentions an umbo in some forms of 

 nitida " behind the orifice," and he shows how *S'. trispinosa var. 

 nitida is subject to great variation with regard to the avicularia 

 and the peristome. 



Loc. Gulf of Manaar {Th.) ; "Africa" (J.); Red Sea (W.). 

 Wasin, Brit. E. Africa, 10 fath. (520), collected by Crossland. 



Smittina trispinosa, var. spathulata MacGillivray. 



Waters, " Mar. Biol. Sudanese Red Sea," Journ. Linn. Soc, 

 Zool. vol. xxxi. p. 156. 



The ovicell has a distinct area, the border of which sometimes 

 rises as an umbo, or is divided into two sharp, erect processes. 

 S. trispinosa var. biniucronata Hincks belongs to this group, but 

 it is doubtful whether it should be separated as a variety, as there 

 is normally such considerable variation in the zooecia. From 

 (504) there are very large vicarious avicularia, directed either 

 distally or proximally. 



Smittina is used instead of Smittia, though not including all 

 that Levinsen refers to it, for I consider it a group in which the 

 operculum is usually very thin, almost membranous, with the 

 lower edge straight. In the species so far examined, the oral 

 glands are quite small and usually more or less attached to the 

 tentacular sheath. In the aperture a lyrula is usually found with 

 the operculum under the cardellfe but over the lyrula. Pseiidn- 

 /lustra solida Stimp., and Lepralia jjaUasiana, together with its 

 allies, show many difi'erences and do not seem to belong here. 



Loc. Bass's Straits ; Torres Straits ; Red Sea. Wasin, Brit. E. 

 Africa, 10 fath. (520) ; Ras Osowamembe, Zanzibar Channel, 

 10 fath. (504), collected by Crossland. 



* "The Brvozoa of the Woods Hole Region," Bull. Bur. of Fisheries, vol. xxx. 

 p. 246 (1912)." 



