BRYOZOA FUOM ZANZIBAR. 483 



Loc. Madeira (-5.); St. Paul's Rocks, IST. Atlantic {Challenger), 

 shallow water. lias Osowamembe, Zanzibar Channel, 10 fath. 

 (504) ; Prison Island, Zanzibar, 8 fath. (505), collected by 

 Crossland. 



Oatenicellid^. 



In the Oatenicellidae the ovicells are of much more use in 

 classification than has been generally recognised, but Levinsen 

 has ignored them in his synopsis of the genera, nor has he used 

 the shape of the opercula. 



Based upon the form of the ovicells, there are two main 

 divisions : — 



First, those in which the ovicell is a terminal gonoecium, as 

 Scuticella Lev., Costaticella* Maplestone, Crihricella 'f Lev., all 

 three of which have an operculum with a straight or but slightly 

 curved edge, and Galpidmm, which has a sinus. In all these 

 genera the ovicelligerous zooecium has a much wider operculum 

 than the ordinary zooecium, but the proximal edge is straight, 

 although in both the gonoecium of all of these, and the ordinary 

 zooecium of the first three, there may be an apparent sinus in 

 the calcareous wall. 



Second, those in which the ovicell occurs in a node with other 

 zooecia ; divided into 



I. Species with the ovicell occurring between two zooecia in a 

 straight line and the operculum straight or nearly so on the 

 proximal edge ; and here we have Vittaticella t Maplestone, in 

 which the ovicell is partly imbedded in the superior zooecium and 

 is surrounded by a beaded structure ; also Catenicella delicatula 

 Wilson and Claviporella pulchra MacG. have the ovicell in the same 

 position but perforated all over. Perhaps a new genus is required 

 for these two, and C. %mxhonata% B. may have to be included. 



II. Species with the tuberculate imperforate ovicell at the end 

 of a mother zooecium of a biglobulus, namely, C. perforata B., 

 C. taurina B., G. cornuta B., but very few ovicells have been seen 

 in this group, and perhaps it is a matter of secondary importance 

 whether they are on a biglobulus or a triglobulus. 



III. Species with the ovicell belonging to the mother zooecium 

 of a triglobulus, mcXnding Pterocella Lev., which has a double area 

 to the ovicell and the ovicelligerous aperture difierent from those 

 of the ordinary zooecia ; Strong ylopora \\ Maplestone, with a per- 

 forated ovicell and the operculum straight at the proximal edge 



* " Further Desc. of the Tert. Polyzoa of Victoria," Proc. Roy. Soc. Vict. vol. xii. 

 n. s. p. 9 (1899). Levinsen, in making the genus Gosticella, evidently overlooked 

 the fact that Maplestone had already made a genus Costaticella, of which the type 

 was lineata, a species included bj' Levinsen in his Costicella. 



t As indicated in the ' Zoological Recoi'd,' the name Grihricella has already been 

 used by Canu for a fossil belonging to the family Adeonidse. 



X The surface of none of tlie Vittaticella seem to be perforate, but smoath or 

 papillose, but some have wrongly been described as perforate. 



§ Described vmfusca bj' MacGillivra^y. 



II This Levinsen calls Tlincksiella, but Maplestone has priority, as his gen is was 

 described in 1899 (Proc. Rov. Soc. Vict. vol. xii. p. 4). 



Piioc. ZooL. Soc— 1913, No. XXXIII. 33 



