CO^GRYLIA—DITHYRA. 12. 41 



Pennant, Br. Zool. iv. p. 178. 

 Donovan, Brit. Shells ii. tab. 41, fio-. 1, 

 Linn Trans, viii. p. 50. 

 Turton, British Fauna, p. 151. 

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

 Dillwyn, Descript. Catal. p. 86. 

 Turton, Conch. Diet p. 172. 

 Mus. nost. From Dawlish and Guernsea. 



Shell more than half an inch 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 the 

 larger end, curving over the flat 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. 



