SPONGES. 213 



the sponge in various directions (but mostly more or less at right angles to the 

 surface), and not by any means confined to the neighbourhood of the larger canals. 

 These bands are, as already suggested by SCHUJ^ZE for closely similar structures in the 

 Adriatic bath sponge, probably muscular, and their function appears to me to be to 

 effect the contraction of the sponge as a whole and thus squeeze the water out very 

 thoroughly when necessary. 



This Ceylon bath sponge appears to differ from most of the varieties of Euspongia 

 officinalis in the greater slenderness of the very pale-coloured secondary or connecting 

 fibres of the skeleton. SCHULZE gives the average thickness of these fibres in 

 Euspongia officinalis as 0'03 millim. to 0'035 millim., while in our variety they 

 attain only a thickness of about 0'02 millim., and are often less. 



Owing to this character the sponge acquires a remarkable softness, but at the same 

 time loses somewhat in durability. This want of durability may impair its value as 

 an article of commerce, but in view of its softness and elasticity and its great absorbent 

 power, combined with its good shape and size, I am inclined to think that it would 

 be worth while to experiment in the way of placing it upon the market if it can be 

 obtained in sufficient quantity. 



R.N. 37 (several specimens in spirit); 101 (dry). All from Trincomalee. 



Euspongia tenuiramosa, n. sp. 



Sponge consisting of irregular, slender branches, usually only about 5 millims. or 

 6 millims. in diameter and apparently repent. The branches are more or less angular 

 or nodose, and usuaUy very crooked. The surface is more or less concealed by coarse, 

 calcareous debris, such as the shells of large Foraminifera, &c. Where free from 

 foreign matter, it is covered with small, sharp conuli, scattered at very various intervals. 

 Vents small and few ; pores not observed. Colour (in spirit) purplish-brown or 

 nearly black. Texture, where free from foreign matter, which occurs internally as 

 well as at the surface of the sponge, compressible and resilient. The longest branch 

 is about 60 millims. in length by 5 millims. in diameter, but the diameter varies 

 much. 



The skeleton is an irregular but fairly close, polygonal- or sometimes quadrangular- 

 meshed network of rather dark-coloured fibre varying much in diameter. Here and 

 there primary fibres can be recognised running into the surface conuli, and these may 

 contain a rather slender core of broken sponge-spicules. The primary fibres have ;i 

 diameter of about 0'05 millim. The connecting fibres vary from about the same 

 diameter downwards to about O'OOB millim. The diameter of the meshes varies so 

 much that it is useless to give measurements. 



The material is not very well preserved for histological investigation, but, so far 

 as 1 have been able to make out, the internal anatomy offers no features of special 

 interest and agrees closely with that of other species of the genus. The flagellate 

 chambers are small, about 0'024 millim. in diameter, and nearly spherical, and the 



