CARDITA.— Plate III. 



here represented is the true Cardita incrassata of Sower- 

 by. Conrad appears to have figured an ordinary speci- 

 men of the Cardita antiquata for it (American Marine 

 Conchology, pi. 8. p. 39); that shell cannot however be 

 described as being " oblong," and this may still have 

 been one of the species referred twenty years since to the 

 Chama antiquata. 



Species 12. (Mus. Cuming.) 

 Cardita marmorea. Card, testa elliptico-ovatd, postic'e 

 rotundatd, antice peculiariter brevi ; lacted, nigro 

 umbones versus maculatd ; costis quindecim sedecimve, 

 recto -elongatiuscule radiantibus, latescentibus; anti- 

 cis crenatis, intus eburned. 



The marble-like Cardita. Shell elliptically ov: 

 rounded posteriorly, peculiarly short anterior 

 milk-white, spotted or rather blotched towards 

 umbones with black; ribs fifteen or sixteen 

 number, increasing gradually in width and radiat 

 in a rather straightly elongated direction ; ante 

 ribs crenated, interior white as ivory. 

 Reeve, Pro. Zool. Soc, 1843. 

 Hab. New Holland. 



This shell may be recognised by its peculiarly nar 

 elongated form, the ligamental area describing a c 

 plete angle with the anterior ; the ribs do not rad 

 from the umbones in a curved direction as in the 

 ceding species, but nearly straight. 



