250 CO^GRYUA—DITHYRA. 56. 



Tab. nost. 11, fig. 18. 

 Tellina lacustris. Gmelin, Syst. p. 3242. 



Turton, Linn. Syst. iv. p. 197. 



Chemnitz, vi. p. 139, tab. 13, fig. 135. 



Pennant, Brit. Zool. iv. p. 184. 



Linn. Trans, viii. p. 60. 



Wood, Conch, p. 197- tab. 47, fig. 5. 



Dillwyn, Descript. Catal. p. 104, 



Turton, Conch. Diet. p. 180. 

 Cardium lacustre. Montagu, Test. Brit. p. 89. 



Turton, British Fauna, p. 154. 

 Pectunculus pusillus rostratus. Lister, tab. 159, fig. 15. 

 Mus. nost. Stagnant waters, and slow streams. 



Shell a quarter of an inch long, and a little more in breadth, 

 slightly angular at one side, thin, transparent, often covered with 

 an ochraceous coat, sometimes black towards the beak from the 

 dried and shrunk animal, rather flat : beaks very prominent and 

 obtuse, like tubercles, which however are less visible in the young 

 ones. 



** ohliqum, incequilaterales, 4, 5. 

 oblique and inequilateral. 



amnica. Cyclas testd obliqud subdepressd incequilaterali transversim sulcata) 

 umbonibus tumidis. 

 Shell oblique rather flat inequilateral, with transverse grooves and 

 the beaks tumid. 



