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



base. On the tentacles there ai'e transverse I'ows of spicules. 

 All the spicules are warty spindles. 



As there is no sign of the union of the polyps into bundles, this 

 form cannot be referred to the genus S2:>ongodes (Kiikenthal's 

 Dendronejjhthya). It falls rather into the old genus Spongodia, 

 one of the features of which was the occuri'ence of isolated polyps. 

 This is now termed Stereonejjhthya by Kiikenthal, and defined 

 as follows : — 



Yery stiff Nephthyida;, whose polyps are not disposed in lappets 

 or bundles, but occui' singly or in small groups directly on the 

 stem or on the main branches, which have few twigs or none. 

 Polyps with Stutzblindel. 



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. 



Locality. Zanzibar, Ohuaka. 



LiTHOPHYTUM ELEGANS (Kiikenthal) =Ammothe A 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 Avith 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. 



Locality. Zanzibar Channel, 10 fathoms, also Ohuaka Bay, 

 East Ooast 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 vaiy from 0-08-0-18 mm. in length and from 

 0-04-0-06 mm. in breadth. The spicules in the inner canal-walls 

 of the stem are in length and breadth, in millims. : — 0'54x0"12; 

 0-3 X 0-067; 0"4x-07r 



Locality. Wasin, 10 fathoms. Previously recorded from Baui 

 and Muemba. 



LiTHOPHYTUM BRASSicuM (Kiikenthal) = Abimothea brasstca 

 May. 



This species is represented by one specimen, which agrees very 

 closely with the type. The polyps vary from 1-1 "2 mm. in length 

 and from 0"6-0'7 mm. in breadth. The polyp-spicules vary from 

 0"12-0*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 O'l 4-0*4 mm. and in breadth from 02- 

 0"03 mm. Mr. Orossland describes the colour of the living 

 specimens as " weak cocoa." 



