44 BIVALVES. CARDIUM. 



CARD1UM Cockle or Heart-shell. 

 DIVISION I. HEART-SHAPED, VALVES COMPRESSED, UM- 



BONES ALTERNATING. 



Cardissa Venus' s heart. Roseum Smooth edged. 



Hutnanum Concave. Monstrosum Recurved. 



DIVISION II. SUB-CORDATE, LONGITUDINALLY RIBBED. 



FAMILY 1. Having a crescent shaped cavity beneath the 



umbones. 

 Retusum Diana* 's. 



FAMILY 2. Ribs armed with nodules, elevated rough strife, 



wrinkles, or scales. 



Edule Common. Regulare Regular. 



Unedo Strawberry. Glaucum Glaucous. 



Fragum White strawberry. *Fasciatum Banded. 

 Hemicardium Heart-shaped. *Elongatum Lengthened. 

 Tuberculatum Tuberculated. Leucostomum White-mouth 'd. 

 Isocardia Rasp. Magnum Yellow ribbed. 



Pecdniforme Pecten. Rigidum Rigid. 



Maculatum Spotted. 



FAMILY 3. With ribs armed, more or less spined. 

 Flavum Yellow. Rugatum Gaper. 



Spinosum Spined. Latum Broad. 



*Echinatum Rake. Ciliatum Ciliated. 



Lima Asiatic. *Aculeatum Spinous. 



Muricatum Prickly. *Muricatulum Minute. 



FAMILY 4. With ribs unarmed. 

 Costatum Pipe-ridged. Oblongum Oblong. 



Medium Marbled. Papyraceum Paper. 



Donaciforme Triangular. Fimbriatum Furbelowed. 



*Exiguum Pigmy. Rusticum Banded. 



Ringens Toothed. Islandicum Iceland. 



*Parvum Diminutive. 



