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Show 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 \ariablo distance, and that the polyps are restricted to the upper regions. In representative specimens there are 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 corresponding 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 vary from 0*12-0*3 m m . in length and from O'Ol-0'02 m m . in breadth ; those of the stem from 0*16-0*3 m m . in length and 0*016-0*02 m m . in breadth. Loccdity. Zanzibar. Previously recorded from Tumbatu Island, (>ff Zanzibar. PARASPONGODES STRIATA Thomson k Henderson. A very fine specimen, 15 centims. in height by 12 centims. in maximum breadth. In its preserved state it is quite flaccid and has an umber-brown colour. The polyps are borne in bundles of 9-21 ; all the polyps in a bundle reach nearly the same level. They are about 1 m m . in length and 0*75-0*9 m m . in breadth. The polyp -spicules are slender spindles, usually straight and covered with few warts. They are from 0*16-0*4 m m . in length and from 0*015-0*04 m m . in breadth. The stem-spicules may be divided into three groups :-(a) long slender spicules with few spines, from 0*3-0*9 m m . in length and from 0*02-0*035 m m . in width; (b) ball-like spicules with many prominent spines; and (c) small irregular X-shaped spicules, very rough and with prominent spines. The two last types vary in length from 0*06- 0*2 m m . and in breadth from 0*04-0*12 m m. Locality. Wasin, 10 fathoms. Previously recorded from the Gulf of Manaar. Subfamily SIPHONOGORGIN^E. SlPHONOGORGIA INTERMEDIA, sp. 11. (Plate XXX. figs. 1 k 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 completely 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 |