210 COl^CEYUA—DITHYRA. 46. 



Shell about two inches in diameter, infinitely varying in colors, 

 shades and markings, with the surface very rough to the touch : the 

 outline is a little oblique, and the under valve is flatter. 



subrufus. Pecten testd wquivalvi aquilaterali glabra, radus 20 rotundatis leevi- 

 bus. 

 Shell equivalve equilateral and smooth, with 20 rounded smooth 

 rays. 



Tab. nost. 17, fig. 1. 

 Ostrea subrufa. Donovan, British Shells, i. tab. 12. 



Turton, Linn Syst. iv. p. 264. 

 Mus. nost. From Torbay. 



Shell about an inch in diameter, of an uniform rufous-brown 

 color, and entirely smooth except a few transverse scaly marks to- 

 wards the margin : the valves are equal, and it has not the oblique 

 outline always observable in the Pecten opercularis, and the ribs are 

 rounded and smooth. 



sinuosuf. Pecten testd suborbiculari incequivalvi, vari^ distortd, radmjiumerosis 

 ■'■ echinatis. 



Shell somewhat orbicular inequivalve, variously distorted, with nu- 

 merously prickly rays. 



Tab. nost. 9, fig. 5. 

 Ostrea sinuosa. Gmelin, Syst. p. 3319. 



Turton, Linn. Syst. iv. p. 261. 



Linn. Trans, viii. p. 99. 



Dorset Catal. p. 38, tab. 10, fig. 3 and 6. 



Dillwyn, Descript. Catal. p. 262. 



