OCR Text |
Show 424 PROF. J. A. THOMSON AND MR. W. D. HENDERSON ON [Apr. 10, Almost all the polyps are directed towards one of the two flattened surfaces. The polyp-stalk is about 1*5 m m . in length, and is loosely covered with longitudinally disposed spicules. On the anthocodia? there are eight double rows of spicules with about eight in each row. Two or three pairs at the top of each row are longer than the others and converge into a triangular projecting point. The orange-coloured Stiitzbiindel spicule projects slightly beyond the anthocodia for about 0*5 m m . The anthocodia has a rounded cauliflower-like form, and the tentacles are neatly incurved on the oral surface, exposing aboral rows of white spicules transversely arranged. The armature of the polyp is the distinctive feature of this species. Loccdity. Mouth of Wasin Harbour, 10 fathoms. SPONGODES ZANZIBARENSIS, sp. n. (Plate XXVIII. fig. 1.) A n incomplete specimen of a beautiful colony, predominantly of a canary-yellow with pink polyps. It belongs to the divaricate section of the genus, and as the contour is irregular and the polyparium flattened it should be referred to Kiikenthal's cervicornis group. The dimensions are 2*5 centims. in height, 2*5 centims. in maximum breadth, 0*8 centim. in thickness. The polyps are by no means crowded, and occur singly or in bundles up to seven in number. Their stalks are short, about 1 millim. in length ; their mouths are directed inwards and downwards: the Stiitzbiindel has a pair of projecting pink or yellow spicules extending for about 0*5 m m . beyond the anthocodia. On the wall of the anthocodia there are eight double rows of about ten pink spicules in each row; those on opposite sides converge, and each row ends in a triangular point. The tentacles bear a transverse series of yellowish spicules. Over the general surface there is a loose network of large, curved, yellow- spindles, below which there is a crowded stratum of small semitransparent forms. All the spicules are spindles with numerous small spines. The following measurements of spicules were taken :-(a) Stiitzbiindel 3x0*15; (b) superficial spindles 2*5x0*12; (c) pink spindles of anthocodia? 0*9 X 0*08 ; (d) subjacent coenenchyma spicules 0*2x0*03. This form does not agree with any of the short-stalked species in the cervicornis group. Loccdity. Wasin Channel, 10 fathoms. SPONGODES KUKENTHALI, sp. n. (Plate XXXI. fig. 5.) A very beautiful species which seems to be referable to a position near S. (Dendronephthya) coronata. It belongs to the umbellate type, is slightly flattened, and has an approximately regular outline. Its dimensions are 6 centims. in height, 6*5 in breadth, and 3*75 in thickness. The stem and branches are very rigid; five of the lower branches are foliate and nearly encircle |