BIVALVES. 



PLATE LVII. 



Genus. SOLEN. 



Character. Shell oblong, and gaping on each side ; tooth concealed, not inserted 



into the opposite shell ; the lateral margin smoothed off. 



Species. 



No. 1. Solen viride. Shell green without, white and red within, party-coloured 

 red and green, oval shaped and flattened, kidney shaped, the ends termi- 

 nating unequally in respect to size. A native of the Asiatic Seas and 

 Coasts. 



No. 2. Solen angulatum. Shell olive coloured, and marked with longitudinal 

 green veins, long and tapering from the hinge each way. A native of the 

 Coasts of Spain. From a shell in the collection of Mr. Bullock. 



No. 3. Solen flammeum. Shell of a bright, red and orange colour, oval and 

 rounded, richly marked with scarlet streaks and spots. From the African 

 Seas. 



No. 4. Solen legumen. Shell of a rich brown colour, streaked across with dark 

 veins, ends rotundate, in form slightly angular and curved, in the manner 

 of a scythe. A native of the Coast of Sierra Leone. 



Genus. CARDIUM. 

 Character. Shell equilateral, equivalve, generally heart-shaped ; the hinge having 

 two teeth, the side teeth inserted remote. 

 No. 1. Cardium cruentum. Shell heart-shaped and pointed; the body richly 



variegated with red spots, the valves nodding to each other, leaving a 



hollow recess underneath the hinge. From a shell in the Collection of 



Mr. Bland. 

 No. 2. Cardium costatum. Shell of a pale brown, with white ribs of different 



sizes, having yellow bands inserted between each ; the ribs angular, pointed, 



and projecting. 

 No. 3. Cardium fragum. Shell white, shaded, and spotted with brown, flattened 



and angular in its general form, with narrow projecting ribs placed 



irregularly. A native of the American Seas. . 



REMARKS. 



The genera Solen and Cardium are essentially distinguished by the different form of the 

 hinge, and the thin transparent character of the former, the Cardium being generally very 

 thick and strong, and more rounded in its shape. In this last genus i% comprehended the 

 Cockle, so familiarly known that it needs no particular description. The Cardium is fre- 

 quently found in a fossil state, in beds of clay or slate in the interior parts of England and 

 France, but no instance has hitherto occurred of the Solen in a fossil state, which, however, 

 is very plentiful in a recent state, upon all the European coasts, under the name of the Razor 

 Bill. As it differs very much in the varieties of its external form, there might be, perhaps, 

 no impropriety in forming it into two different families according to its shape ; but till the 

 knowledge of Nature becomes more extended, we shall find the Genera of Linnaeus the 

 most illustrative and comprehensive. 



