203 



Spindle i)art 6 x 02, spines 0'3 long giving in all 06 x 0-5. 



„ 0-6 X 0-22, „ 0-275 „ „ „ „ 06 x 0-495. 



,. 0-6 X 0-2, „ 0-38 „ „ „ „ 0-6 x 0-58. 



(d) Irregular forms with warted branches on one side, smooth spines on 

 the other, 0-6 x 0-5 ; 0-6 x 0-48, i.e., inclusive of spines. 



{(') Warty spindles, 0-6 x 0-1. 



(/) Spindles bifurcated at both ends, 0-6 long, 0-18 in thickness and 

 25 l)etween the terminal points. 



(//) Irregular plates with warty branches, 0-6 x 0-3. 



(//) Smooth spindles of the anthocodise, 05 x 0-03 ; 052 x 003 ; 046 x 0-02. 



Locality : Kalpeni Bank, Laccadives. Marine Survey. 



Another fragmentary si)ecimen is recorded from Arakan Coast ; 13 fathoms. 



Echinomuricea andamanensis, n. sp. 

 Plate I. hg. 8 ; Plate VIII. fig. 2. 



A complete colony of a brown colour growing on a piece of rock covered 

 with Polyzoa ; it is 90 mm. in height and 80 mm. in maximum diameter. The 

 branching is in one plane. At a short distance from the base the main stem 

 bifurcates ; the subsidiaiy stems ascend almost vertically, but are joined at 

 two points by fusion with secondary branches. The branching is quite irregular, 

 but nearly all the branches arise almost perpendicularly ; many keep their 

 original course but others curve and twist in the interspaces. Fusion however 

 is not infrequent. 



The axis is horny and comjmratively hard though flexible ; the surface has 

 a bright sheen of a dark bronze colour. 



The coenenchyma is fairly thick so that the branches have an almost uniform 

 diameter throughout, except at the tips which are swollen and club-shaped. 

 The surface has a glistening arenaceous appearance. 



The polyps are disposed irregularly over the whole coenenchyma but in some 

 places an almost spiral arrangement is discernible. The verruca? are not 

 prominent but give the surface an undulating contour. They are more spinose 

 than the ccenenchyma, and around the ai)erture there is an indefinite serrate 

 margin. The anthocodipe are almost completely retractile but show a distinct 

 octo-radiate horizontal operculum. This consists of a collaret of about three 

 rows of curved spindles surmounted by eight triangles each composed of five 

 spicules. Four of these are arranged " en chevron " enclosing an acute angle, 

 while the fifth, which is considerably smaller, fills the basal interspace. The 

 spicules are colourless. The following are the more prominent types with 

 measurements, length by breadth, in millimetres : — 



