346 



Cell. (Lagenipora) socialis and Cell. (Celleporella) pijijmaeu, on the other hand, there 

 is on the circumference of each zooeciuni a small number (6—8) of widely sep- 

 arated, thin canals by means of which each zooecium is connected with its neigh- 

 bours. At the bottom of each canal there is a rosette-plate with one pore. This 

 agreement in regard to the interzocecial connection cannot however be considered 

 as an index of a close relationship between the two species mentioned, as we 

 must refer them to two diJTerent genera owing to a presumably more important 

 difference in the structure of the oa'cia. 



hi the majority of the species belonging to this family the ooccium consists 

 of two calcareous layers, of which the ectoooecium is as a rule provided with 

 [)ores. These may however be lacking in a few species, for instance in Cell, soci- 

 alis and in C. ramiilosa the ooecia are only rarely provided with pores, hi a small 

 group of species, concerning which Waters' has already expressed the ojjinion 

 that they should form a special genus owing to the structure of the ooccium, the 

 ectoooecium is only partially calcified, and the frontal wall of the endoooecium 

 has a flat, semilunar, semicircular or circular area which is covered by a mem- 

 branous part of the ectoocucium, whilst the part of the endooa'cium correspond- 

 ing to the area is provided, sometimes with radiating grooves or fissures, 

 sometimes with scattered pores. For this group we would propose the name 

 Siniopelta. An ocrcial cover may sometimes appear, for instance in Cell. ai)iciil(tris- 

 and Cell, socialis. 



Cellepora Linne. 

 Cellepora Busk, Hincks part.; Olleporella Hincks part.; 

 Lagenipora Hincks, Scliismojiora Mac Gillivray part.; 

 Osthimosia Jullien. 



The ectoooecium is wholly calcified and generally furnished with pores, in 

 lare cases without such. With exception of Cellepora Costazzi all the species of 

 Cellepora described by Hincks in British Marine Polyzoa belong to this genus, 

 and with exception of C. riidis all those which Busk refers to the group S 2 in 

 his Challenger Brtjozoa. Other species have been described by Mac Gillivray, 

 Waters, Jullien and others. To this genus I must also refer Lagenipora socialis 

 Hincks, of which 1 have examined a number of colonies lent me by the British 

 Museum and by Mr. Waters. The ectoooecium is without pores but wholly 

 calcified and furnished with an ooecial cover which hides its basal half. Among 

 the ordinary zooecia there is a number of flat kenozooecia wliich Hincks men- 



' 113, p. 13; 108, p. 20. « 103, PI. IX, figs. 194—96, 



