1 92 1.] Mampur Molluscs. 631 



been unable to include in m}' revision of the Indian species of the 

 genus Sphaeriniii {supra, p. 614) owing to insufficient information. 

 As a result of my examination of the unique type I am now able 

 to confirm the author's opinion of his species from Burma being 

 a distinct species. In the Indian Museum I was also fortunate 

 in finding a specimen in Theobald's Burmese collections of Uni- 

 onidae which is referrable to this species. Unfortunately the 

 exact locality of Theobald's specimen is not known. 



I have nothing to add to Tapparone-Canefri's description, 

 but give below the measurements of the type-shell and of Theo- 

 bald's specimen. I have also taken this o^Dportunity to publish 

 a figure of the shell and the hinge-teeth of the type-specimen. 



Measurements {in millimetres). 



Tj'pe-specimen. Theobald's specimen. 

 Length .. .. 8-2 8-i 



Breadth . . . . 7-3 7-4 



Thickness . . . . 4 3-9 



Tapparone-Canefri compared his species with S. indicum . 

 Deshayes, but was doubtful as to its possible identity with S. 

 avanum, Theobald. The species, however, has no relationship 

 with S. avanujii, and forms a distinct group with S. indicum and 

 S. austeni. From either of these species it is easily distinguished 

 by its subquadrate shape, less tumid shell, less prominent umbones, 

 which do not project so far upwards and inwards as in the other 

 two species, proportionately larger lateral teeth and in having 

 the two lamellar cardinals of the right valve distinctly separated 

 from each other by a fairly deep notch. 



[B. Pr.\shad.] 



