CONCHYLIA—D/Tl/ Fli^. 21. 6i 



Mus. nost. Scotch and western coasts. 



Shell a quarter of an inch long, and nearly half an inch broad, 

 white, but often covered or blotched with an ochraceous coat, 

 obscurely wrinkled transversely : beaks placed near one end, 

 obtuse : one of the teeth in each valve erect, the other much bent 

 inwards and sloping downwards. 



MoNTACUTA testa ohlongd leevi, dentibus erectis. obionga. 



Shell oblong smooth, with all the teeth erect. 



Tab. nost. 11, fig. 11 and 12. 

 Mus. nost. From sand in Torbay. 



Shell resembling the last, but is about half the size, smooth or 

 very obscurely striate transversely, glossy. It has probably been 

 overlooked for a half-grown specimen of the former shell, but 

 differs essentially in having all the teeth erect. 



21. LEPTON—TC/i? TOA'. 



Testa compressa, suborbicularis, a-quivalvis, ccquilateralis, la- 

 teribus subhiantihus. Cardo valvce alteritis dente unico et 

 laterali utrinque lineari transverso ; alterins fovea media et 

 dente utrinque laterali transverso bipartito, segmentis ab 

 umhone divaricatis. Ligamentwn internum. 



