PHARELLA. 343 



Shell transversely elongated, gaping and rounded at the 

 extremities. Hinge usually with two hooked primary teeth 

 in one valve, and three in the other. Pallial line with a 

 deep, rounded sinus.. 



Genus PHARUS, Leach. 



Siphons separate, diverging, fringed at the ends. 



Shell thin, compressed, sub-equilateral, invested with an 

 epidermis, beaks sub-central; valves, beneath the hinge, 

 strengthened by a strong, oblique rib. Hinge with three 

 teeth in the right valve, the central one bifurcate ; a single, 

 compressed, primary tooth, and a bifid, sub-lateral one in the 

 left valve. Anterior adductor impression elongate, hori- 

 zontal; pallial line with a short, wide sinus. 



Sf/n. Solecurtoides, Desmoid. Polia, D'Orb. Cerati- 

 solen, Forbes. 



Fa;. P. legumen, Linnaeus, pi. 92, fig. 3. Shell, P. 

 legumen, fig. 3, a, 3, b. 



A single species only of this genus is at present known, 

 inhabiting the sandy shores of the Mediterranean, the Red 

 Sea, Senegal, and the British Islands. It is found in a 

 fossil state in the Pliocene of Italy. 



Genus PHARELLA, Gray. 



Siphons shortly produced and separate. Foot large, ab- 

 ruptly truncate. 



Shell sub-cylindrical, transversely greatly elongated, 

 rounded and gaping at both extremities, beaks sub-anterior. 

 Hinge composed of two teeth in one valve, and three in the 

 other. Anterior adductor scar elongate, sub-trigonal ; pallial 

 line with a small sinus. 



