OStREA. 129 



the upper-valve a little convex, with a whitish depression 

 near the hinge, the ribs strongly striate, which gives them 

 a somewhat angular appearance, of a deep rufous brown 

 color j the lower valve white, very convex, with the ribs 

 much rounded and the grooves between them very deep, 

 and nearly smooth or with only a few longitudinal lines 

 on the lateral ribs ; in which last circumstance it is distin- 

 guished from O. maxima : ears equal, striate in a decussate 

 manner; inside white, rufous round the margin: length 

 three or four inches ; breadth four or five. 

 Western coasts, and Dublin bay. v. v. 



3. Ostrea opercuhiris. Painted Scallop. 



Lister, pi. 182. f. 19, pi. 190. f. 27, pi. 191. f. 28, and 

 192. f. 29 Pennant, pi. 63. f. 2 Da Costa, pi. 9. f. 1, 

 2, 4, 5 Linn. Trans, vi. pi. 18. f. 7, 8 Dorset Cat. pi. 9. 

 f. 1,2, 4, 5. 



Pecten subrufus. Donovan, pi. 12. 



Shell nearly orbicular, with about twenty rounded ribs, 

 striate both longitudinally and transversely, giving the sur- 

 face a roughened or slightly beaded appearance ; one of 

 the valves much more convex than the other : color and 

 markings in endless varieties of white, yellow, brown, red, 

 or purple, sometimes plain, but mostly marbled or spotted, 

 and which are much more richly displayed on the deeper 

 valve j inside white, polished", frequently tinged with other 

 colors, with a tooth-like projection each side in each valve 

 just below the ears : ears nearly equal, ribbed transversely 

 and striate longitudinally : diameter two inches and a half. 



Variety. White, with a red longitudinal line down the 

 centre of the ribs, on the convex valve. Fig. 74. 



Lister, pi. 170. f. 7. 



Ostrea lineata. Da Costa, pi. 10. f. 8 Donovan, pi. 116, 

 Dorset Cat. pi. 10. f. 8. 



It will be clear to any one who closely examines 

 this variety, that the supposed subearinated appearance 

 of the ribs, is merely caused by the red line down the mid- 

 dle of each. In all other respects it is precisely similar to 

 the O. opercularis. The ribs in both are rounded at the 

 bottom of the shell, and put on a gradually more sharpened 

 edge as they approach to the hinge 3 and we have observed 



that 



