OCR Text |
Show 426 PROF. J. A. THOMSON AND MR. W. D. HENDERSON ON [Apr. 10, base. On the tentacles there are transverse rows of spicules. All the spicules are warty spindles. As there is no sign of the union of the polyps into bundles, this form cannot lie referred to the genus Spongodes (Kiikenthal's Denclronephthya). It falls rather into the old genus Spongodia, one of the features of which was the occurrence of isolated polyps. This is now termed Stereouephthya by Kiikenthal, and defined as follows:- Very stiff Nephthyida?, whose polyps are not disposed in lappets or bundles, but occur singly or in small groups directly on the stem or on the main branches, which have few twigs or none. Polyps with Stiitzbiindel. The spiculation of the anthocodia (15-20 pairs of spicules in each double row) is one of the well-defined diagnostic features distinguishing this form from the eight species recognised by Kiikenthal. Loccdity. Zanzibar, Chuaka. LITHOPHYTUM ELEGANS (Kiikenthal) = AMMOTHEA ELEGANS May. In this specimen the polyps vary from 1*1-1*25 in length and have a diameter of 0*7 mm. The polyp-spicules vary from 0*16- 0*17 mm. in length with a diameter of 0*01 mm.; the stem-spicules vary in length from 0*3-0*4 mm., and in breadth from 0*01-0*02 mm. The colour of the specimen when living was pink with brown zooids. Loccdity. Zanzibar Channel, 10 fathoms, also Chuaka Bay, East Coast of Zanzibar. Previously recorded from Tumbatu, an islet near Zanzibar. LITHOPHYTUM VIRIDE (Kiikenthal) = AMMOTHEA VIRIDIS May. This species is represented by several specimens, which agree in every detail with the description given. The polyp-spicules vary in length from 0*1-0*24 mm., and in breadth from 0*015-0*03 mm. The stem-spicules vary from 0*08-0*18 m m . in length and from 0*04-0*06 m m. in breadth. The spicules in the inner canal-walls of the stem are in length and breadth, in millims.:-0*54x0*12; 0*3x0*067; 0*4x*07. Loccdity. Wasin, 10 fathoms. Previously recorded from Baui and Muemba. LITHOPHYTUM BRASSICUM (Kiikenthal) = AMMOTHEA BRASSTCA May. This species is represented by one specimen, which agrees very closely with the type. The polyps vary from 1-1*2 m m . in length and from 0*6-0*7 m m. in breadth. The polyp-spicules vary from 012-0*34 mm. in length, and in breadth from 0*016-0*02 mm.; the stem-spicules, which are slender with few wart-like spines, vary in length from 0*14-0*4 mm. and in breadth from 0 02- 0*03 mm. Mr. Crossland describes the colour of the living specimens as " weak cocoa." |