158 Records of the hidian Museum. [Voi,. X, 1914.] 



tions, therefore, the skeleton is composed of slender tylostyles 

 of very variable size and proportions. One extremity is sharpl^?^ 

 and gradually pointed, while the other forms a distinct head, 

 which usually bears some resemblance to an acorn, being divided 

 into a rounded terminal portion, as a rule longer than broad, 

 and an enlarged ring-like base. The differentiation is, however, 

 not always distinct and the exact form of the whole head is 

 very variable. The largest macroscleres are about 0"033 mm. in 

 length and their stem nowhere exceeds 0"0i56 mm. in thickness. 

 The curvature of the spicules is usually slight and regular, if 

 they are not absolutely straight; but some are a little sinuous 

 and a few are always to be found in which the stem is curved or 

 angularly bent at one point. The head is relatively small, as a 

 rule distinctly longer than broad. 



Type No. Z.E.V. ^¥*' Ind. Mus. 



Habitat. — Chilka Lake, Orissa, near the east coast of India, 

 in brackish water on leaves of Halophila and shells of Ostrea; 

 also on the latter in the backwater at Bnnur near Madras. This 

 sponge has been found at two places in the Chilka Lake, namely 

 about a mile off Burkul near the inner shore and at Manikpatna 

 in the outer channel a few miles from the mouth.' At the former 

 place several very young specimens were found in July on the 

 leaves of a plant actually floating on the surface but probably 

 detached from the bottom in about 6 feet of water. The speci- 

 mens from Manikpatna are larger and were found in September on 

 the external surface of the valves of oysters {Ostrea sp.) living 

 in about 4 feet of water. 



In its form and method of growth this sponge approaches 

 Prosuberites , Topsent, but the possession of horizontal spicule- 

 fibres distinguishes it from the species of that genus. 



^ Further particulars about the distribution, etc., of this sponge will be given 

 in a subsequent paper on the fauna of the Chilka Lake. Feb. 24th, 1914. 



