116 
Hab. Singapore; on dead shells, ten fathoms, in coarse sand and 
gravel. Mus. Cuming; one small specimen. 
5. ANOMIA ACHUS. 
Shell purplish, smooth ; umbo rather acute ; upper valve generally 
convex ; inside purplish white. 
Upper muscular scar large, lower edge slightly arched; lower 
sears 2, small, nearly equal-sized ; the hinder rather lower than the 
other. 
Hab. Indian Ocean, Kurachee, mouth of the Indus. Brit. Mus. 
and Mus. Cuming. 
Major Baker has kindly sent to the Museum a very large series of 
the dorsal valves of this species, collected at Kurachee. They are ex- 
tremely variable in form, surface, colour and thickness, and they also 
offer considerable variety in the disposition of the muscular scar. In 
all the upper scar is largest, but variable in shape from round to 
broad cordate. In most the two lower scars are close together, but 
separate, and nearly on the same line. In others the lower scar is 
rather lower than the middle one, and in a few (four) specimens, which 
are mostly produced posteriorly, the lower scar is much lower; that 
is to say, in some the upper edge is parallel with the lower edge of 
the middle one. In one specimen the two lower scars are on the 
same line, and are confluent together, forming a scar about the same 
size as the upper scar, yet showing that the lower scar is formed by 
two muscles; so that this valve cannot be confounded with a Placu- 
nanomia. 
The examination of this series of specimens from the same locality 
-T think shows, that though the comparative size and disposition of the 
scars may furnish good characters for the distinction of the species, 
yet they are not to be implicitly relied on. 
6. ANoMIA BELEsIS. (Mollusca, pl. 4. fig. 3, 4.) 
White or red; the upper part of the centre of the dorsal valve 
white, externally radiately striated; apex acate, at some distance 
from the dorsal edge. 
Upper valve with three separate scars, the upper one very large 
oblong, and rather transverse; two lower ones very small, nearly equal- 
sized, and nearly on the same line. 
Hab. Indian Ocean? General Hardwicke. Brit. Mus. 
+tt American. 
7. ANOMIA ACONTES. 
Yellowish white, suborbicular, flat, smooth; disk pearly. 
Upper scar moderate, stbcircular ; lower scars smaller, distant, 
circular, subequal, the lower one nearly on a line with the lower edge 
of the middle one. 
Hab. Jamaica; Gosse. Mus. Cuming; one small specimen. 
8. ANOMIA FIDENAS. 
White, pearly, thin, flat, smooth externally, pearly within, with a 
thick white disk. 
