428 PROF. J. A. THOMSON AND MR. W. D. HENDERSON ON [Apr. 10, 



of the stalks, that the stalks are united with one another for 

 a variable distance, and that the polyps are restricted to the upper 

 regions. 



In representative specimens there ai-e several upright branches 

 dividing into finger-shaped ends, which bear numerous polyps 

 not densely disposed. One colony is 6"5 centims. in height and 

 5 centims. in breadth at the top. The whole colony is soft 

 and compressible, with longitudinal grooves coi'resjDonding to the 

 canals. The preserved specimens are whitish yellow. 



The spicules are long slender spindles with very few small and 

 distant spines. The polyp-spicules vaiy from 0*1 2-0-3 mm. in 

 length and from 0'01-0'02 mm. in breadth ; those of the stem 

 from 0"16-0'3 mm. in length and 0-016-0"02 mm. in breadth. 



Locality. Zanzibar. Previously I'ecorded from Tumbatvi Island, 

 off Zanzibar. 



Pakaspongodes striata Thomson & Henderson. 



A very fine specimen, 15 centiius. in height by 12 centims. in 

 maximum breadth. In its pi'esei-ved state it is quite flaccid and 

 has an umber-brown colour. The polyps ai-e borne in bundles of 

 9-21 ; all the polyps in a bundle reach nearly the same level. They 

 are about 1 mm. in length and 0"75-0'9 mm. in breadth. 



The polyp-spicules are slender spindles, usually straight and 

 covered with few warts. They are from 0'16-0"4 mm. in length 

 and from 0'015-0"04 mm. in breadth. The stem-spicules may be 

 divided into three groups : — («) long slender spicules with few 

 spines, from 0"3-0"9 mm. in length and from 0"02-0'035 mm. in 

 width ; (5) ball -like spicules with many prominent spines ; and 

 (c) small irregular X-shaped spicules, very rough and with pro- 

 minent spines. The two last types vary in length from 0"06- 

 0"2 mm. and in breadth from 0"04-0'12 mm. 



Locality. Wasin, 10 fathoms. Previously recorded from the 

 Gulf of Manaar. 



Subfamily Siphonogorgin^. 



SiPHONOGORGiA INTERMEDIA, sp. n. (Plate XXX. figs. 1 ife 2.) 



The most puzzling specimen in the collection is a small cream- 

 coloured colony, with four finger-shaped lobes on a short trunk. 

 On each lobe there are a few relatively distant polyps occurring 

 all round. Most are well-expanded, but some are all but com- 

 pletely retracted into the coenenchyma. 



At first sight the colony suggested a small Alcyonium ; but the 

 polyps have a well-developed anthocodial armature, and the walls 

 of the stem-canals are supported by numerous spicules, some very 

 large. Moreover, the whole somewhat granular surface is covered 

 with a delicate but coherent layer of small spicules. 



The anthocodial part of the polyp is supported by eight triangles 

 of sloping spindles, which diverge into a brush-like apex at the 

 base of each tentacle. In some there were 4-5 distinct pairs of 



