ia 
CONCHOLOGY. 09 
dermis; the surface beneath is white, with several violet streaks 
radiating from the summit to the margin; two furrowed cardinal 
teeth upon one valve, three upon the other, the middle one being 
largest and callous; muscular impressions double and lateral. 
Inhabits the rivers of Ceylon. One species. 
Galathea radiata. 
FAMILY X. 
Carpiacea. Five Genera. 
1. Genus Cardium. Pl. VII. 
Animal. Body somewhat inflated; mantle edged with tenta- 
cular cirri in all its inferior part ; tubes united, of moderate size, 
and provide with cirri at the extremity; mouth transverse, very 
wide, with moderate labial appendages ; foot very large, cylindri- 
cal, somewhat inclined anteriorly ; branchie thick, rather small, 
especially the external lamine: the internal united in all their 
extent. 
Shell. Inflated, equivalve, sub-cordiform (when viewed ante- 
riotly, usually costated from the apex to the circumference) ; 
summits very evident, but slightly flexed to the front; hinge com- 
plex, similar, formed of two oblique, conical cardinal teeth, and of 
two distant lateral teeth, upon each valve ; ligament dorsal, poste- 
rior and very short. Inhabits the European and American seas. 
Fifty-seven living species. Fourteen fossil. 
’ Cardium indicum. Cardium costatum. 
C. Asiaticum. C, ringens. 
C. fimbriatum. C. tennicostatum. 
C. aculeatum. C. psudolima. 
C. tuberculatum. C. erinaceum. 
C. apertum. C. Basilianum. 
C. bullatum. C. papyraceum. 
©. echinatum. C., ciliare. 
C, biradiatum. C. levigatum. 
C. pectinatum. C. eolicum. 
C. isocardium. C. elongatum. 
C. angulatum. C. rugosum. 
C, serratum. C. unedo. 
