Zoological Society. 216 



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 

 I 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. 



White or red ; the upper part of the centre of the dorsal valve 

 white, externally radiately striated; apex acute, 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. 



ttf American. 



7. Anomia acontes. 



Yellowish white, suborbicular, flat, smooth ; disk pearly. 



Upper scar moderate, subcircular; 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. 



Upper scar large, elongate, arched below ; lower scars 2, small, cir- 

 cular, far apart, the lower one considerably below the other. 



Hab. America, west coast. Panama ; on Pinna at low water. 

 Mus. Cuming, No. 2 ; three specimens. 



9. Anomia adamas. 



Red, thick, with numerous indistinct radiating ribs, most distinct on 

 the edge of the lamina ; internally red, pearly, with a small white disk. 



Upper muscular scar oblong, arched below ; lower scars subequal, 

 separate, but close together, and nearly on the same line. 



Hab. Galapagos ; Lord Hood's Island, attached to Avicula mar- 

 garitifera at nine fathoms. Mus. Cuming, No. 5 ; three specimens. 



10. Anomia pacilus. 



Red, with distinct radiating ribs ; internally reddish pearly, with a 

 thick white disk. 



