2;38 CONCHYLIA— DIT/yrKyi. 53. 



ostrcoides. DiSClNA 



Discina ostreoides. Liamarck, Syst. vi. p. 377. 

 Orbicula Norwegica. Ijumarck, Syst. p. 242. 

 Patella anomala. Gmelin, Syst. p. 3721. 



Turton, Linn. Syst. iv. p. 585. 

 Anomia turbinata. Dillwyn, Descript. Catal p. 286. 

 Patella distorta. 3Iontagu, in Linn. Trans, xi. p. 195, tab. 13, 

 fig. 5. 



Turton, Conch. Diet. p. 140. 

 Mtis. nost. Attached to submarine stones. 



Shell hardly half an inch in diameter, rather flat, rugged and 

 very irregular in the circumference; the upper valve brown, 

 with a small wart-like protuberance which is not quite central . 

 in'^ide minutely granulate : the under valve thin, white or blueish 

 white, and attached to submarine stones. 



1 



53. A^ODON— LAMARCK. 



Testa transversa, fpqtiivalvis , ina^qni/aferalis, laterihus subhi- 

 antibus. Cardo edentutns, lamina iransversd anticd sinii 

 terminatd. JLigamentum externum. 

 Shell transverse, equivalve, inequilateral, a little open at the 



sides. Hinge without teeth, furnishod witii a transverse lamina 



