40 GO^CUYUA—DITHYRA. 12. 



The specific name incequivalvis, originally given to this and the 

 Tellina insequivalvis, is now quite inapplicable in consequence of its 

 forming an essential part of the generic character. We have there- 

 fore, after Lamarck, been induced to exchange them for names more 

 appropriate. 



12. T A^^DOn A~LAMARCK. 



Testa transversa, cequivalvis, incequilateralis, latere antico hiante. Car- 

 do valv(B planatcB dente unico cum foveold longitudinali ; valvae con- 

 vexts foveolis duabus longitudinalibus : lateralibus nullis. Ligamen- 

 tum internum. 



Shell transverse, inequivalve, inequilateral, open at the anterior end. 

 Hinge of the flat valve with a single tooth and longitudinal cav- 

 ity, of the convex valve with two longitudinal cavities : lateral 

 teeth none. Ligament internal. 



luargaritacea PaNDOEA 



Tab. nost. 3, fig. 11 to 14. 

 Tellina inaequivalvis. Linn. Syst. Nat, p. 1118. 

 Gmelin. Syst. p. 3233. 

 Turton, Linn. Syst. iv. p. 189. 

 Chemnitz, vi. p. 115, tab, 11, fig. 106. 

 Montagu, Test. Brit. p. 75, suppl. 27. 



