532 MR. A. W. WATERS ON 



The tentacular sheath is attached to the operculum close to its 

 border, and on the inner side of the opercular region there is a 

 small globular body (fig. 2), immediately below which the new 

 bud grows. We see the same thing in various species, among 

 others, in "i Bifaxaria vagans Thorn., J. poli/stomella Rss., etc., 

 and it is very large in Adeona foliacea vdv . fascialis Kirchenpauer, 

 being about 0*4 mm. in diameter, which is about double the 

 diameter of the globe in the present species. The wall is thick 

 and it may give support to the new bud. 



There are about 13-14 tentacles. A. distoma has 14-16. 



It would seem that the ovicellular zooecia very frequently occur 

 near to a bifurcation, and there may be a group of three or four 

 ovicellular zooecia close together. The few ovaria seen consist of 

 two very small ovarian cells, at first situated at the distal end of 

 the zocecium, but others, no doubt older, occur by the pi-oximal 

 end of the ovicellular sac. The ovaria are similar to those of 

 Bugula, and are of about the same size in Adeonella platalea, 

 A . polystomella *, and A . crosslandi. The early stages of develop- 

 ment have not been made out. 



The ordinary zocecia may have the polypide entirely surrounded 

 by a testis, in fact, may be practically filled with it. 



Loc. Wasin, Brit. East Africa, 10 fath. (500, 501), collected by 

 Crossland. 



EXPLANATION OF THE PLATES. 



Plate LXIV. 



Fig. 1. Aetea anguina L. Showing the ovicell {ov.) at the end of the tubiilar pro- 

 jection ; the retractor muscles (rjw.) attached just 

 below the tentacles, and also attached at the other 

 end near the commencement of the basal expansion, 

 where the ovaria {oa.) also occur. X 85. Frosn 

 Wasin (500). 



2. Do. do. Front view, showing the operculum and the tentacular 



sheath {ts.) to which the muscles are attached. X 250. 



3. Aetea trimcata Landsborough. X 25. From Prison Island (505). 



4. Brettia tropica, sp. n. X 85. Dorsal surface. From Wasin (501). 



5. Do. do. X 25. Anterior surface. 



6. Catenaria diaphana Busk. X 25. From Eas Osowamembe (504). 



7. Do. do. Lateral view, X 25. 



8. Do. do. Operculum, X 85. 



9. Do. do. X 25. Section showing embryos (l.) in the ovicell; 



also an ovum (ov.) in the zocecium, and ovaria below 

 the ovicell {oa.). 



10. Do. do. Ovarium, X 250. 



11. Do. do. X 85. Section of zooecium showing ovicell {ov.), 



diaphragm {d.), compensation-sac (es.). 



12. Synnotum pemhaensis, sp. n. X 25. From Chaki-Chaki Bay, Pemba 



Island (517). 



13. Do. do. Mandible, X 250. 



14. Do. do. Avicularium, X 85. 



15. Do. do. X3. 



16. Synnotum contorta, sp. n. X 25. From Chaki-Chaki (517). 



17. Do. do. Avicularium, X 150. 



18. Do. do. Mandible, X 250. 



* A. polystomella occurs in the Red Sea, as I find from the examination of a 

 specimen in the British Museum, since m^^ Red Sea paper was written. There is 

 also a specimen from Brisbane (65.5.29.4). 



