1906.] ALCYONARIANS FROM ZANZIBAR. 425 



the stem ; the stem gives oS a large number of primaiy branches 

 which break up into secondaries and these bear the twigs with 

 umbels of polyps. The trunk and base ai'e wanting. The spicules 

 on the surface of the genei'al coenenchyma are transparent near 

 the base and pale yellow higher up. Just below the polyp-bearing 

 twigs some of the yellow spicules show a red core, and there is 

 thus a gradual transition to the crimson-red spicules of the polyp- 

 stalk, anthocodia, and tentacles. 



The polyps are arranged in small clusters of 7-10 ; and these 

 are again grouped into larger umbels. Though there is no 

 crowding, the polyps form a fairly continuous covering. A polyp is 

 usually about 1"5 mm. in length and is covered by longitudinally 

 disposed spindles. Three large ones form a strong Stiitzbiindel 

 which projects beyond the anthocodia for about 1 mm. The 

 anthocodia stands almost at right angles to the polyp-stalk, and is 

 supported by red spindles in 8 double rows, about 7 pairs in each 

 row. A distinctive feature is that the topmost spicules of each 

 double row project in triangular points beyond the bases of the 

 tentacles. The tentacles are white, but bear numerous small red 

 spicules ari'anged transversely, so that a fine tentacular operculum 

 is formed over the contracted polyp. 



The spicules are spindles with fine warts oi' short blunt spines, 

 and show a great range of colour. Some are red, some are yellow, 

 some are combinations of these colours, and others are ti'ansparent. 



The largest are those of the Stiitzbiindel, about 4 mm. in length 

 by 0"2 in breadth, and some of those on the polyp-stalk ai'e about 

 3 "5 mm. in length. Those of the general surface of the 

 coenenchyma are : 2x0-15 mm.; 1-8 x 0-15 ; 1*5 x 0*1; 1-35 x 0*1; 

 0-8 X 0-1; 0-35 X 0-04; 0-3 x 0-03. 



The red spicules of the anthocodipe are mostly about 0*6 x 0"04 ; 

 a projecting one had a length of 1'2 x 0"06. 



Locality. Wasin. 



Stereonephthya zanzibarensis, sp. n. (Plate XXXI. figs. 3 

 &4.) 



A small but complete colony of a yellowish tint, 10 mm. in 

 height and 8"5 in breadth. The trunk of the colony is limp, but 

 the main polyp-bearing part is stifF and brittle. The polyps have 

 shoi't stalks about 1 mm. in length ; some arise from the trunk, 

 bvit most are borne on the branches. They occur close together, 

 bvit ai'e not united into bundles. The anthocodia stands at right 

 angles to the stalk and has its oral opening dii-ected towards the 

 branch. The Stiitzbiindel has one main projecting spicule 

 (l"2x0'125 mm.) supported by 2 or 3 bent spindles on either 

 side ; below these there are a few in the direct line of the 

 projecting spicule, passing continuously into the superficial sjjicules 

 of the coenenchyma (0"6, 0*4, and 0'25 mm. in length). On the 

 antliocodia3 thei'e are eight double rows of spindles, each row 

 consisting of 15-20. The oj^posite members of a double row slope 

 towards one another at an acute angle, which widens towards the 



