CONCHY U\—DITHYRA. 12. 41 



Pennant, Brit. Zool. iv. p. 178. 

 Donovan, Brit. Shells, ii. tab. 41, fig. 1. 

 Linn. Trans, viii. p. SO. 

 Turton, British Fauna, p. 151. 

 Wood, Conch, p. 201, tab. 47, fig. 2 to 4. 

 Dillwyn, Descript. Catal. p. 86. 

 Turton, Concli. Diet. p. 172. 

 Mus. nost. From Davvlish and Guernsea. 



Shell more than half an incii long, and twice as broad, oval- 

 oblong, white with a pearly gloss, smooth or marked with a few 

 transverse ridges, sloping to the anterior end in a rather curved 

 manner; the convex valve angular down the slope; beaks near 

 tlie larger end, curving over the fiat valve which is slightly striate 

 transversely on the outside, and longitudinally within : the tooth 

 is prominent and obtuse, placed rather longitudinally. 



Young shells have the cardinal margin nearly straight, with 

 the anterior end obtuse and rounded ; and in this state are the 

 Solen Pinna of Pennant, p. 175, tab. 67, fig, 3, and of Montagu, 

 p. 566, and Suppl. 27, tab. 15, fig. 3. 



