BTIYOZOA FROM ZANZIBAR. 465 



Aetea truncata Landsboroiigh. (PI, LXIV. fig. 3.) 



There are only small fragments from Prison Island, Zanzibar 

 Channel. The creeping tube oi' stolon is dotted in just the same 

 way as the erect tube. 



Loc. Arctic ; British ; Danish ; Madeira, Naples, Rapallo, 

 Cette. Prison Island, Zanzibar Channel (505), 8 fath., collected 

 by Crossland. 



Fossil. Helvetian, Egypt (Canu). 



Brettia tropica, sp, n. (PI. LXIV. figs. 4, 5.) 



There are only the zocecia figured, and it will be seen that the 

 species is closely allied to J3. aush-alis Busk, but differs in the 

 shape of the area, which in B. trojnca is about the length of 

 a zooecium. There are on the dorsal surface the two light disks * 

 on each side as in B. longa Waters, but in B. tropica the distal 

 ones are very minute with the proximal one much larger. The 

 lower zooecium arises from a calcareous knob, from which stolons 

 spread out. The zooecium is calcareous, and most of the species 

 of Brettia are more or less calcareous, but Avith such small 

 fragments we cannot know much about its relationships. 



I found species of Brettia in the Arctic and one in the Antarctic, 

 and though the differences are very small it does not seem that the 

 present form can be placed with any of those already described. 

 Brettia may have avicularia, but then it has been called Coryno- 

 porella Hincks. 



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

 Crossland. 



Synnotum aviculare Pieper. 

 Waters, Rep. Sudanese Bed Sea, p. 129. 



Log. (additional). Wasin, Brit. E. Africa, 10 fath. (501) ; Ras 

 Osowamembe, 10 fath. (504) ; Meweni Bay, 6 fath. (510). 



Synnotum pembaensis, sp. n. (PI. LXIY. figs. 12-15.) 



Zoarium with a spreading ramifying stolon, from ^hich several 

 erect stems arise, just as in Stirparia etc. The stem is about the 

 same size as the creeping stolon, and is smooth for about the length 

 of two or three zooecia, then there is a short zooecium followed by 

 the pairs of zooecia. 



The zooecia are shorter and stouter than those of Synnotum 

 aviculare P. At one side, at the distal end there is a round 

 pedunculate avicularium, but no sessile avicularium as in ^S'. 

 aviculare. The first zocecium of each branch is uniserial, as 

 is also the case in S. avicidare, Notamia hursaria L., Dimetopia, 

 and Calicellia, whereas in Gemellaria Im'icata L. there is a pair 

 of zooecia at each fresh bifurcation. The pairs of zooecia turn 

 alternately slightly to right and left, and there aie x^adicles from 

 between the zooecia just as in Synnotum aviculare. There seem 



* There are similar disks in Catenaria and Vittatieella. 



