1918.] N. Annandale : Sponges, etc. of flic Inlc Lahe. 11 



so. The surface is fairly smooth but minutely hispid. The colour 

 is usually bright oreen, but sometimes, without apparent cause, the 

 chlorophyl bodies that produce this colour are absent and it is not un- 

 common for the upper half of a sponge to be green and the lower half 

 yellowish white. Sponges on bamboo posts are brownish yellow. 



The skeleton, as might be expected from the softness of the sponge, 

 is very sparse and the number of spicules smaller than usual in the 

 Spongillidae. Slender spicule-fibres can, however, be detected forming 

 an open and fairly even network in the parenchyma. The radiating 

 fibres are more clearly defined than the connecting fibres and can be 

 traced from near the centre of the sponge to the surface. They bifurcate 

 at fairly regular intervals. On the surface they support the epidermal 

 membrane over a fairly extensive subdermal space and project through 

 it as microscopic spines. 



There are no '" bnbble-cells." 



The skeleton-spicules are slender and sharply pointed. Though 

 often a little irregular in outline, they never appear, even under the 

 highest powers of the microscope, granular or spinv. Abnormal 

 macroscleres of cruciform or bifid outline are not uncommon. 



There are no free microscleres. 



The gemmule-spicules are of the type normal in the species, with 

 shafts considerably longer than a single rotule. They bear few but 

 often very stout and long spines, which project at a right angle. These 

 spines are often arranged in a circle round the middle of the shaft. 

 The rotules are unevenly and deeply denticulate but well-developed and 

 normal. 



The gemmules are ver\ small, spherical and of a bright vellow colour. 

 Their pneumatic layer is relatively thin and they are surrounded bv a 

 single row of gemmule-spicules. The microphyle is crateriform viewed 

 from outside but contains a small tubule that projects at right angles. 



Measurements {in millimetres). 



Length of skeleton spicule ... ... ... 0-238 — 0-357 



Diameter of skeleton spicule ... ... ... 0-012 



Length of gemmule spicule ... ... ... 0-028 — 0-032 



Diameter of rotule ... ... ... ... 0-02 



Diameter of gemmule ... ... ... 0-6 



Type-specimen. — No. P. 30/1, Zoological Survey of India {Indian 

 Museum). 



The most noteworthy features of this variety are the extreme softness 

 of the sponge, which often collapses in drying into a mere slimy layer, 

 and the regularity of the arrangement of the radiating fibres of the 

 skeleton. The first of these characters, though always well marked, 

 is variable in degree. All the sponges from any one spot as a rule are 

 similar in respect to it, but I was unable to correlate extreme softness 

 with any factor in the environment. 



The skeleton-spicules differ from those of the Himalayan forni^ of 

 the species in that they are not at all granular or spiny. 



1 E phyda Ha fluviaiilis suhs]^. himalayensis, Annsbxid^ile. Rer. Ind. Mvs, VII, p. 138, 

 fig. 1 (1912). See also Journ. As. Soc, Bengal, XI, p. 44.5 (1915). 



