t^^l

222 CTEEXIDTE.
strong fairly distant ribs, periostracum 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 much
arched and long ventral margin -, posterior margin slightly curved
and merging into the dorsal and ventral margins ; ligament short,
fairly strong and prominent; interior of shell dull, nacre white,
marked with fine narrow brown rays^ of which three are equallv
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.
Bab. ? India.
363. GorMcula ncetliagi, v. Martens.
Corhicula nostlingi, v. Martens, Arch. Natg. Berlin, Ixv, 1899, p. 47,
pi. 4, figs. 7-9. ^
? Vyrtma moussoniana (Deshayes), Sowerhy in Reeve, Conch. Icon.
XX, 1878, pi. 17, fig. 97 (non moussoni, Desh., Cat. Brit. Mus.,
Conchif. 1854, p. 227).
Shell posteriorly elongated, in form somewhat resembling Vemts
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 spaces between, anteriorly
and posteriorly becoming gradually reduced to shght strisB ;
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. 16, lat. 22, diam. 11 mm.
Uab. Bakmio.
364. Corl)icula arata (Sowerby).
Cyrma arata, Sowerhy, Conch. Icon, xx, 1878, pi. 17, fig. 93.
Original description:—Testa ovata, tenuissima, rosacea, tumidissima,
liris magnis, distantibus ad latera suboblique terminantibus
rugata, epidermide aurantio-flavida iiiduta; latere antico rotuudo.