312 



T. testa ovatft aut obovata, magis minusve ventricosa, solidius- 

 cula, subnitidii, subltevigata, subsequilaterali, extus intusque albida, 

 lineis obsoletis pallidioribus subradiata, epidermide pertenui lutes- 

 cente induta ; margitie ventrab antice arcuato, postice sursum 

 acclinato; dorsali antice prope nates acutas subrecto deindeque 

 arcuato et subdeclivi, postice subretuso et valde declivi; latere 

 antico longiore, rotundato ; postico attenuate, angulato, et paululum 

 subrostrato ; flexura costaque umbonali satis conspicuis ; ligamento 

 promimdo; dentibus minimis. 



Ovate or obovate, more or less ventricose, not very strong, 

 rather glossy, nearly equilateral, whitish both M'ithin and without, 

 covered by a very thin yellowish ash-coloured epidermis, nearly 

 smooth being merely wrinkled by the lines of growth, peculiarly 

 marked with obsolete radiating lines; ventral edge arcuated in 

 front and rising behind ; anterior side rather the longer, its extre- 

 mity rounded, its dorsal edge at first nearly straight and then 

 arched and moderately sloping ; posterior side attenuated, angu- 

 lated, and very slightly beaked ; fold and flexure tolerably distinct ; 

 ligament short and slightly prominent ; teeth very small. 



Gambia. 



In typical examples there is a slight groove-bke depression 

 behind the fold, which does not exist in the next species. 



178 Tellina Cayennensis (pi. lxii. f. 190.) Psammobia C. 

 Lam. no. 1 1 ; Hani. Des. Cat. p. 58. sup. 1. 11. f. 48 ; Deles. Eec. 

 t. 5. f. 7 ; T. constricta, Phil., Ab. und Bes. Conch, part 3. t. 5. 

 f . 5 ; T. intastriata, Say, Jour. Ac. Nat. Sc. Philad. 



T. testa ovali-trigona, solida aut solidiuscula, magis minusve 

 ventricosa, subinaiquivalvi, subinsequilaterali, nitidiuscula, extus 

 intusque albida, epidermide cinerascente induta, sublsevigata; mar- 

 gine ventrali convexiuscido ; dorsali antice convexo et subdeclivi, 

 postice subrecto et declivi ; latere antico paulo longiore, rotundato ; 

 postico cuneiformi; natibus recte incurvatis; ligamento promi- 

 nulo, satis magno; flexura costaque umbonali satis conspicuis; 

 dentibus baud parvis. 



Triangularly-oval, more or less solid and ventricose, slightly 

 inequivalve and inequilateral, scarcely glossy, nearly smooth, whitish 

 within and without, covered by a very thin ashy epidermis ; ven- 

 tral edge slightly convex ; dorsal convex and moderately sloping 

 in front, straightish (never incurved) and strongly sloping behind ; 

 front side rounded, rather the longer ; hinder side wedge-shaped ; 

 beaks incurved ; ligament little prominent, and as well as the teeth, 

 of a moderate size ; fold and flexure tolerably distinct. 



