1915J Fauna of the Chilka Lake . Sponges. 41 



Gemmules are developed abundantly. Individually they resemble those found 

 in the other phase of the species, but they form, instead of a flat basal layer, serpentine 

 masses (fig. 6, p. 39) that meander through the sponge-like veins of mineral in a rock. 

 Bach of these masses has in its centre some foreign body such as a filament of alga 

 or a branch of Bimeria and there is no essential difference in the two phases except 

 that the gemmules in phase B are attached to foreign bodies of the kind instead of 

 to the basal membrane. 



Suberites sericeus was described from Kagoshima in Japan and has not hitherto 

 been recorded, so far as I am aware, from any other locality. In the Chilka Lake 

 we found it both in the outer channel and in the main area. In the latter we dis- 

 covered accidentally that the bottom of the '' Lady of Chilka ' , which then lay off 

 Barkuda Id. , was coated with masses of the sponge in its more robust phase. 

 This was in July, 1914. In the outer channel specimens of the less robust form 

 were taken in September, 191 4, at four stations, in all cases in very small quantities. 



The sp. gr. of the water, which was quite fresh in the outer channel in Septem- 

 ber, was 10145 at Barkuda Id. in July. The depth at which the sponge was collected 

 varied from about 2 feet to about 2 fathoms. 



The species seems to stand alone in the genus ; from other species the structure 

 of its skeleton, as well as the form of its spicules, separates it. It has no close relation- 

 ship to the genus Laxosuberites , to which Topsent, who had evidently not seen a' 

 specimen, proposed to assign it (pp. cit., 1900, p. 184). 



The phase A was found in the Chilka Lake coating the leaves and stems of 

 Halophila ovata and other plants, while in Japan it was taken on the shells of 

 Gastropod molluscs. The phase B has only been found on the bottom of a steam- 

 launch. The small size and feeble development of the former may possibly be 

 connected with the small area to which it was confined, while the circumstances in 

 which the robust sponge was growing, on the only occasion on which it has yet been 

 seen, were perhaps unusually favourable for its growth. The fact that one phase 

 was taken in brackish and the other in fresh water was probably accidental. 

 Gemmules were found in both forms in the circumstances described. 



On the f Lady of Chilka ' the sponge had grown over an assemblage of small 

 mussels (Modiola striatula) as. well as many colonies of the hydroid Bimeria flumina- 

 lis. Some of the latter seemed to be quite dead, but others were valiantly holding 

 their own and budding out fresh polyps on the surface of the sponge. Of the 

 mussels a few also survived and had succeeded in keeping open, over the tips of 

 their shells, slit-like apertures through which they could obtain food and water. 

 But the majority had perished and been completely buried. In some cases the 

 two valves were found still cohering at the narrow end but forced widely apart at 

 the other and coated inside and out with living sponge. In others the valves were 

 shut or almost so, and the remains of the animal, not yet completely liquified, were 

 still held between them. In yet others the sponge was beginning to force the shells 

 apart at the broad end and to invade their inner surface ; the remains of the animal, 

 rendered liquid by putrefaction, were being gradually absorbed. These facts are 



