COBMCULA. 219 



striae ; anterior side rounded ; posterior side somewhat angularly 

 rounded; lateral margins sloped; ventral margin rounded, slightly 

 contracted towards the posterior side ; umboes large ; interior of 

 shell purplish-white. 



Long. 1O5, lat. 12 mm. 



Hob. Phenchooganj, Sylhet, Assam. 



Type in the Indian Museum, Calcutta. 



Allied to C. iravadica, Benson, but is more trigonal and more 

 swollen. 



357. Corbicula quilonica, Benson. 



Corbicula quilonica, Benson, A. M. N. H. ser. 3, vi, 1860, p. 260. 



Corbicula quilonensis [sic] Benson ; Prime, Ann. Lye. Nat. Hist. 

 N.Y. viii, 1866, p. 224, fig. 56; Cat. Corbiculidse, 1869-70, 

 p. 135, no. 87; Clessin, in Martini Chemnitz, 1879, p. 135, 

 pi. 24, fig. 10. 



Original description: Testa inaequilaterali, trigono-rhomboidea, 

 gibba, tenui, concentrice subremote costata, costis postice evanes- 

 centibii'i, sulcis intermediis latioribus, sub lente decussatim striatis, 

 albida vel lutea, radiis fuscis angustis ornata ; umbonibus promi- 

 nentibus, apice fere eroso ; latere antico breviore, valde arcuato, 

 angustiore, postico striato, latiore ; superue et basin versus 

 ungulata ; margine ventrali mediocriter arcuato ; ligamento ob- 

 longo intra nates attenuate ; pagina interna valde concava, albida, 

 maculis radiisque purpureis ornata ; dente mediana valvae dextra? 

 duplici, dentibus lateralibus brevibus serrulatis. 



Long. 8, lat. 10, diam. 5'5 mm. 



Hub. Xear Quilon, in (probably brackish) ponds. 



The author adds a note to his description from which the 

 following may be quoted : " The younger shells are more gibbous 

 towards the uinbones in proportion to their length than the larger 

 specimens. A tawny-yellow epidermis covers the fresher speci- 

 mens. The rays are numerous, more or less broad, sometimes 

 appearing as mere lines of small spots, and occasionally spreading 



so as to make the surface appear nearly black The 



shortness of the lateral teeth, on the anterior side especially, is a 

 notable character, as well as the insequilateral form, which is- 

 more conspicuous in the young than in the adult shell." 



358. Corbicula alberti, Preston, nom. nov. 



Corbicula violacea, Clessin, in Martini & Chemnitz, 1879, pp. 180- 

 181, p. 30, figs. 18, 19. 



Shell small, almost equilateral, swollen, fairly thin, polished, 

 shining, strongly and distantly ribbed, covered with a dark olive- 

 brown periostracum ; anterior side scarcely attenuated, rounded ;. 

 posterior side dilated, truncated ; vertical transverse section 

 cordate ; horizontal contour ovate ; umbones broad, inflated, 



