76 CLASS I. TROPIOPODA. ORDER I. BIMUSCULOSA. 



the genus Sanguinolaria being exactly intermediate between the genera 

 Solecurtus and Psammobia. 



The shell of Sanguinolaria is equivalve, inequilateral, transverse, some- 

 what elliptic, compressed, thin, and a little gaping at both sides ; the 

 margins curved and not parallel to each other. There are two cardinal 

 teeth situated close to each other in each valve, sometimes bifid ; and 

 there is also a prominent testaceous appendage or fulcrum on the um- 

 bonal margin, as in many of the Solenacea. The muscular impression of 

 the mantle exhibits a large sinus. 



Examples. 



PI. LII. Fig. 1 and 2. 



Sanguinolaria rosea, Lamarck, Anim. sans vert., new edit., vol. vi. 



p. 169. 

 Tellina rosea, Gmelin. 

 Solen sanguinolentus , Dillwyn. 

 Psammobia rosea, Deshayes. 



PI. LII. Fig. 3 and 4. 



Sanguinolaria diphos, Sowerby, Genera of Shells, No. 25. 

 Solen diphos, Chemnitz. 

 Solen rostratus, Lamarck. 

 Psammobia rostrata, Deshayes. 

 Soletellina radiata, De Blainville. 



PSAMMOBIA, Lamarck. 



Testa transversa, oblonga vel ovato-oblonga, lateribus subhiantibus ; 

 epidermide tenui, cornea, induta. Cardo, in valva altera dentibus 

 brevibus duobus, plerumque bifidis ; in altera unico. Ligamentum 

 externum. Impressio muscularis pallii sinu maximo. 



