222 CYREXID.K. 



strong fairly dis-tant ribs, periostraciim yellowish-brown ; anterior 

 side elongated, pointedly rounded, posterior side much shortened, 

 obtuse, umbones much inflated, prominent, generally eroded ; 

 upper margin curved, gradually passing into the side margins ; 

 anterior margin narrow, rounded, gradually passing into the mucli 

 arched and long ventral margin ; posterior margin slightly curved 

 and merging into the dorsal and ventral margins ; ligament shoi-t, 

 fairly strong and prominent ; interior of shell dull, nacre white, 

 marked with fine narrow brown rays, of ^^hich three are equally 

 divided over the surface, running from the umbones to the ventral 

 margin, while the remaining two run towards the hinge-margin, 

 terminating at the lower side of the latter; hinge-margin fairly 

 broad ; cardinal teeth small, not grooved above ; lateral teeth 

 elongated, depressed, the posterior being shorter. 



Long. 9. lat. 10, diam. 8 mm. 



Hnh. ? India. 



3Ge3. Corbiciila ncetlingi, v. Martens. 



Coiiiicula 7ia'tli)i(/i, v. Martens, Arch. Natg. Berlin, Ixv, 1899, p. 47, 



pi. 4, tigs. 7-9. 

 ? Cyrena moussoniana (Deshayes), Sowerhy in Reeve, Conch. Icon. 



XX, 1878, pi. 17, US'. 97 (uou moitssoni, Uesh., Cat. Brit. Mus., 



Conchif. 1854, p. 227). 



Shell posteriorly elongated, in form somewhat resembling Venus 

 or Tapes ; dorsal margin descending more obliquely anteriorly 

 than posteriorly ; anterior margin rounded ; posterior margin 

 rounded above and below, vertically descending in the median 

 region; ventral margin moderately rounded; concentric ribs 

 strong, narrow, half the breadth of the sjmces between, anteriorly 

 and posteriorly becoming gradually reduced to slight stride ; 

 hinge strong ; lateral teeth long, the anterior one bent at the 

 anterior end, the posterior one fairly straight ; interior of shell 

 bright violet. 



Long. 22, lat. 29, diam. 14 mm. 



Hah. Hpaung, N. Shan States (in a small pool). 



The author mentions a small variety which is still more posteriorly 

 elongated and rounded (fig. 7 in the reference to the original 

 description quoted above). 



Long. 10, lat. 22, diam. 11 mm. 



Hah. Bakmio. 



364. Corhicula arata {Sowerhy). 



Cyrena arata, Sowerby, Conch. Icon, xx, 1878, pi. 17, fig. 93. 



Original description : — Testa ovata, tenuissima, rosacea, tumi- 

 dissima, liris magnis, distantibus ad latera suboblique termiuantibus 

 rugata, epidermide aurantio-flavida induta ; latere antico rotundo, 



