188 W. Theobald — Descriptions of new Land and [No. 3, 



radiatim striata. Dentibtis cardinalibus fortibus, in callo costiformi positis, 

 in valva dextra duobus alteraque singulis, subverticalibus. Cicatricibus 

 valde depressis. Pallii impressione valde conspicua. 



Diam. maj. 97, minor 40, crass. 25 mm. 



Habitat in Kistna flumine prope ' Gutparba falls,'' teste A. B. Foote. 



This shell has its valves divided into two subecmal areas by a strong 

 ridge running back and down from the beaks. The lower and anterior por- 

 tion is strongly compressed, simulating the appearance of Area subtorta, 

 though there is no true ' version' in the valves. The strong cardinal rib 

 which supports the cardinal teeth is also a marked feature of this species, 

 as well as its radiating striae intersecting the concentric lines of growth. 

 Unfortunately the beaks are much decayed in my two specimens and their 

 sculpture wholly effaced. 



I am indebted to my colleague Mr. Foote for both shells collected by 

 him at the ' Gfutparba' falls. 



Pisidifm Bomb ay ahum, n. sp. 



Testa subovali, tumida, tenui, inceauilaterali, postice rotundata, viz 

 truncata ; antice rotundata elongata ; exilissime et confertim concentrice 

 striata ; dente cardinali minutissimo ; dentibus lateralibus in valva dextra 

 geminis, in sinistra autem singulis. 



Lat. 4-30, alt. 3"70, crass. 2*70 mm. 



Habitat in Indies occidentalis regione " Western Ghats" dicta, teste 

 W. T. Blanford. 



I have long had specimens of this shell from Western India, and it is 

 the same as that mentioned by Mr. Nevill when describing his _P. Clarkea- 

 num (J. A. S. B., 1871, Part II, p. 9, PI. I, Fig. 4.). The subangulation 

 mentioned by Nevill is more discernible in young shells than in adults, 

 which are symmetrically rounded. This species is extremely closely allied 

 to P. Clarheanum, but is more convex posteriorly. By an inadvertence of 

 the describer the posterior side of P. Glarheanum is described as the 

 longer instead of the anterior as correctly shown in the figure. 



Pisidittm Nevilliakum, n. sp. 



Testa trigona, tumidiuscula, tenui, inaequilaterali, postice modice con- 

 vexa, antice elongata, subacuminata, exilissime concentrice striata ; umboni- 

 bus Icevigatis. 



Lat. 3-60, alt. 3"50, crass. 2-20 mm. 



Habitat prope JRurJci. 



A single specimen only of this species was communicated to me by Mr. 

 Gr. Nevill. Its trigonal form most readily distinguishes it from its 

 allies. 



