MESODESMA. 413 



Genus paphta, Lamarck. 



Shell ovate, sub-trigonal, truncated and slightly keeled 

 behind. Hinge with the lateral teeth small, sub -equal, 

 smooth. Siphonal inflection distinct. 



Sy?i. Eryx, Swainson, not Daud. 



E,v. P. glabrata, Gmelin, pi. 106, fig. 1, 1, a. 



The shells of this genus are triangular and more equi- 

 lateral than in Donacilla or Mesodesma ; the species are 

 found in the sands in various parts of the world. 



Species of Paphia. 



glabrata, Gviel. mitis, Desh. 



intermedia, Desh. striata, Chnel. 



Layardi, Desh. sulcata, Desh. 



macrodon, Desh. trigona, Desh. 



Sub-gen. taria, Gray. 



Shell oblong, sub-equilateral, attenuated behind, hinder slope 

 keeled; lateral teeth very small. Siphonal inflection distinct. 



lnta, Desh. spissa, Reeve. 



Genus MESODESMA, Deshayes. 



Shell ovate, sub-equilateral. Hinge with the lateral 

 teeth short, smooth, sub-equal. Siphonal inflection distinct. 



Syn. Machaena, Leach. 



Ex. M. Novse Zelandiae, Chemnitz, pi. 100, fig. 2, 2, a 



The shells comprised in this genus are usually, when in a 

 vol. ii. 3 ir 



