1906.] ALCYONARIANS FROM ZANZIBAR. - 407 



by iiari'ow stolons but mainly by a coherent membrane. The 

 polyps may attain a length of 5 mm., not inchiding tlie tentacles, 

 which are usually about 3 mm. long. The breadth of a fully- 

 extended polyp is slightly under a millimetre. Some of tlie 

 polyps have their tentacles wholly retracted, and are themselves 

 contracted into sugar-loaf -like prominences about 3 mm. in height. 

 There is no evidence of calcareous bodies either in tentacles or 

 polyps, and the colour of the preserved specimen is translucent 

 white. 



The most characteristic featui-es are presented by the tent&^cles. 

 They measure almost half a millimeti'e at the base, but naiTow 

 somewhat quickly and end in a fine point. They appear to be 

 slightly convex aboi'ally and slightly concave orally. When fully 

 expanded they foi-m a circle about 3'25 mm. in diameter. The 

 pinnules are about nine in number on each side, but the four 

 nearest the base of the tentacle are very short, the longest pinnules 

 being usually numbers 4 and 5 from the distal end ; they are 

 sepai-ated from one anothei' by short intervals ; and towai'ds the 

 base, beginning at the sixth, there is a gradual shunting from a 

 latei-al position on to the oi'al surface of the tentacle. In shape 

 the pinnules ai-e cylindiical, and have a somewhat rugose appear- 

 ance due to conti'action. 



In another specimen, which had a red colour when living, some 

 of the polyps attain a length of 10 mm., not including the tentacles, 

 and are densely packed with eggs and embryos. In the majority 

 the tentacles and the 03Sophageal region ai-e completely retracted 

 within the smooth-walled calyx. In some parts of the colony the 

 polyps are connected by narrow stolons about 1 mm. in diameter ; 

 in others there is a continuous membrane. 



Locality. Cape Yerde Islands. 



Olavularia pregnans, sp. n. (Plate XXX. fig. 3.) 



This interesting form is well marked by two peculiarities. In 

 the fii'st place, the pinnules occur all round the tentacles. This 

 unusual arrangement is also seen in C. inflata Schenk, but, aj)art 

 from the generic characteivs, there is little else in common between 

 the two species. The second peculiarity is that many of the 

 polyps show a large expansion of the body, containing a large 

 embryo or as many as thi'ee. 



There is a thin basal membrane growing over a polyzoon. The 

 polyps, sometimes marked by contraction-rings, are about 5 mm. 

 in length and 1 mm. in breadth, with slender tentacles of 2"5- 

 3 mm. in length by 0'35-0"4 in breadth. No bare streak is 

 to be seen on the tentacles, which ai-e surrounded by short* conical 

 pinnules with a kind of spiral arrangement. Crowded zoo- 

 chlorellfe produce here and there a glistening appearance, but no 

 trace of spicules could be seen. 



Many of the polyps show at a short distance below the tentacles 

 a prominent expansion (2*5 mm. in diameter) of the tube con- 

 taining up to three embryos. As these grow one side of the 



