145 



at the margin. Length four inches ; breadth five ; rarely 

 found ib large in the BriLifJi feas. 



This fpecies very much refembles the P. maximus, but 

 the fijies rife higher towards the hinge ; and it is at once 

 diitinguifhed by the under valve being pure white ; and 

 by the flat, angulated ribs. 



It is a rare fliell, but has fometimes been dredged up on 

 our coafl:, particularly in DorfefJJdre, at Poole and at 

 Weymouth; as we are allured by Doftor Pulteney. 



Da Costa informs us he received it from the fame 

 coafl, as well as from Cornwall, and Scarborough in 

 YorkJJiire. 



3. 

 Ofli-ea opercularis. Lin. Syjl. p.ll46. — Gmel. Syft. p. 3325. 51. Opercularis. 



Pult. Cat. Dorfet. p. 36. 



Turt. Lin. iv, p. 266. 



Lijler Conch, t. 190. f. 21. 2'$,.— Id. Ang. t.5, 

 f. 30. 

 PeiSten opercularis. Chan. Conch, vii. t. 67. f. 646. 



Favan. t. 54. L. 2. 4. 

 Oftrea fubrufus. Don. Br. Shells \. t. 12. 

 PeCten fubrufus. Br. Zool. t, 60. f. 63. 

 Peaen pidus. Da Cojia p. 144. t. 9. f. 1. 2. 4. 5. 



Lin. Trans, vi. t. IS. f. 7. 8. (IVood.) 



P. with a fub-orbicular fliell, with about twenty rounded 

 ribs, finely ftriated tranfverfely : colour various, mofl fre- 



V quently 



:.* 



