T^ol III, IS^o, 1.] Notes on the Freshwater Fauna of India. 21 



of the genus which have hitherto been recorded from India. It is 

 -common in Calcutta. 



Trochospongilla LATogcHiAXA. sp. nov. (Fig. 5.) 



Sponge forming small, shallow, cushion-shaped masses on the 

 stems and roots of water-plants, pale, yellowish-brown in colour ; 

 surface minutely hispid ; pores and oscula inconspicuous ; older 

 specimens divided into two transverse layei's by a definite mem- 



FlG. 5. Trochosponyilla latouchiana. 



Spicules, X about 200. 



brane, the gemmules being confined to the lower layer. Skeleton 

 spicules smooth, stout amphioxi about 15 times as long as bx'oad 

 in the middle, subfusiform, often with one or several irregular 



( Stout amphistrongyli, often dilated in the middle, 

 them occasionally)- Skeleton verv loose and 



projections. 



occur 



among 



iiTegular. No flesh spicules. 



occasionally), 



Birotulates 



of 



very 



simple structure ; 



the rotulse circular, flat or nearly flat, sometimes not quite equal ; 

 •diameter of rotulas 4i to 5 times that of the shaft, which is about 



2i times as 



long as broad. 



Gemmules small, scattered, non- 



adherent, spherical, covei'ed with a thin layei' of miorocell sub- 



stance ; the apei'ture on a slight prominence. 



Avei'age diameter of gemmule 



length of skeleton spicule 



ji 



„ birotulate spicule 



diameter of x-otula 



* * ■ 



0-2 



0-28 



00175 



0-02 



mm 



)» 



J? 



»» 



MeniarJc 



w 



■ This form is related to the N. Amencan species Trochospongilla 

 leidyi ( Bowerbaiik ), from which it is differentiated by its more 

 slender skeleton spicules and the flat or nearly flat discs of its 

 birotulates. Possibly it is no more th 

 species. I have not seen a specimen 

 long and a quarter of an inch deep. 



and elongate, owing to tlie fact that they Avere on 



mencan 



heen 



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