36 Melvill, Molluscan Fauna of the Arabian Sea, etc. 



Periploma indicum, sp. nov. 

 (PI. 2, f. 4.) 



P. testa incequilaterali, inceqiiivalvi, valva sinistra 

 mifiore, valvis ventricosulis, tenuibus, sotdide dlbis, super- 

 ficialiter irregnlariter concentrice striatis, striis rudibus, um- 

 bonibus contiguis, incurvis, margine dorsali utrimque declivi, 

 postice curto, subtruncato, antice ovato-i'otundo, margine 

 ventrali convexiusculo, ab umbonibus tisque ad lateris 

 postici extremitatem unicarinata, carina obtusa, cardine 

 in valva utraque obliquo, cochleari, intus alba, nitida, vix 

 iridescente. 



Alt. 12, lat. 15, diam. 5 mm. sp. maj. 



Hab. Jask ; 4 to 6 fathoms, sand and mud. 



Resembling in form, though not in texture, P. trape- 

 zoides Lam., from California. It is of a dirty white hue, 

 smoothish, the left valve smaller than the right, umbones 

 contiguous, incurved, ligament obscure externally, the 

 shell dorsally declining on both sides of the umbones, the 

 posterior side curtly truncate, the anterior roundly ovate, 

 merging with the convex ventral margin, while an obtuse 

 keel runs from the umbones to the posterior extremity in 

 both valves. The hinge is oblique, spoon-shaped, one in 

 each valve, the shell within is white, shining, not iridescent. 



Seven or eight examples. 



