igig.] B, Prashad : Asiatic Unionidae. 411 



at the tip. The branchial aperture occupies nearly the whole of 

 the curved posterior end of the shell and hence the anal is placed 

 higher above ; it is separated from the anal by a distinct notch and 

 has three rows of elongated papillae on its margin. The anal is 

 about half the size of the branchial and is smooth ; it is separated 

 from the supra- anal by a mantle connection a little more than half 



O.G. 



P." 



Text-fig. 5. — Animal of U)i{o (^Eolymntiim) fei-ni/ualts. reference lettering- 

 same as in tig. 2. 



the size of the anal and very much smaller than the supra-anal. 

 The foot is rather poorly developed. 



The glochidia are unknown, as none of the specimens are 

 gravid. 



This sub-genus comes near the group of U . pictorum^ but differs 

 in the general shape of the animal, the shape and size of the gills, 

 the relations of the branchial, anal and supra-anal apertures, and 

 in the poorer development of the foot. 



