tiENUS VI. TELLINA. 57 



Cardium ; but as they do not quite agree in their teeth with 

 the other Cardiums, perhaps it would be better to follow 

 Lamarck, and make a separate genus of them. 



Lamarck has di\ided this genus into four, as follows: 

 Cyclas. Shell nearly orbicular, or a little transverse, without 

 any fold on the fore part ; cartilage external ; hinge with 

 two or three centre teeth, the lateral ones lengthened, 

 compressed, and intruded (Tellina cornea, Pennant's Brit. 

 Zool. 4. t. 49. f. 36. See/j/. 2. /. 15). 

 LuciNA. Shell nearly orbicular or transverse, without any 

 fold on the fore part ; the centre teeth variable ; two 

 lateral teeth remote (Tellina divaricata Linn. See pi. 3. 

 /. 16). 

 Tellina. Shell orbicular or transverse, having an irregular 

 fold on the fore part ; one or two centre teeth, and remote 

 lateral teeth (Tellina radiata Linn. See pi. 'i. /. 17). 

 Pandora. Shell regular; valves unequal and inequilateral, 

 with two oblong unequal and diverging teeth at the centre 

 of the upper valve, and two oblong corresponding hollows 

 in the other valve ; cartilage internal, two muscular im- 

 pressions (Tellina ineequivalvis. See pi. 2. f. 1 8). 

 It may be remarked here, that probably some shells that 

 have hitherto been arranged with the Tellince will be placed in 

 the genus Sangiduolaria, and also some in Capsa. Perhaps 

 we may place here Lamarck's genus of Corbula, and also 

 Mr. Parkinson's Trigonellites, which are described by them 

 as follows : 



