PECTENIDES. MOLLUSCA. PECTEN. 133 



upper valve moderately convex ; valves widely gaping near the 

 hinge, surface everywhere sculptured with radiating, punctured 

 lines, or grooves, about half as wide as the spaces between them, 

 somewhat zigzag in their course ; these lines are crossed by 

 closely arranged lines of growth, which, on the convex valve, are 

 scolloped or vaulted over the radiating lines; flattened valve 

 white, convex valve dingy reddish-brown, or flesh-colored. Hinge 

 margin narrow, straight, ears equal, the notch in the lower valve 

 rounded, and shallow. Interior white, smooth, glossy, willi 

 minute radiating lines not corresponding to the exterior grooves. 

 Length 5 inches, height 5J inches, breadth 1 J inch. 



This shell is not common on the Massachusetts shore ; but single 

 valves, of a very large size and very solid, are occasionally thrown up, 

 and smaller ones are found in the stomachs of fishes! Its proper habitat 

 is farther north, and along the eastern part of the coast of Maine it is 

 found abundantly in its greatest perfection. It does occasionally pass 

 to the south of Cape Cod, (the usual terminus for northern species) 

 for I have a fine specimen which was drawn up alive, by a hook, off 

 Block Island. 



The general aspect of the lower valve is smooth ; nor do we see 

 any thing like ribs on the upper surface. 



PECTEN ISLA'NDICUS. 



Shell sub-orbicular, reddish or orange-brown; ears unequal; 

 surface covered with small ^ crowded, irregularly disposed, scaly ^ 

 radiating ribs, which re-appear ivithin. 



FIGURE 89. 

 State Coll., No. 151. Soc. Cab., No. 2039. 



O'strea Islandica, MULLER ; Zool. Dan., Prod., No. 2990. LIN. ; fter IVestrogoth., 

 200, t. 5, f. 7. GMELIN ; 3326. No. 55. SHAW ; Zool. Misc., xxiii. I. 978, 987. 

 FABR.; Fauna GrcenL, 415. KNORR ; Delices, fyc., t. i. pi. B. f. 3, 4. LISTER ; 

 Conch., t. 1057, f. 4. GUALT. ; Test., t. 73, f. R. SEBA ; Mus., ii. t. 87, f. 7. 



Pecten Islandicus, CHEMN. ; Conch., vii. t. 65, f. 615, 616. TURTON ; Cotif.lt. 

 Diet., 258. Brit. Biv., 216. DESHAYES ; Encyc. Mttlt., Vers, iii. 724. FLEM- 

 ING ; Brit. Mm., 385, pi. 212, f. 1. LAM.; An. sans Vert., vii. 145. SAY; 

 Amer. Conch., pi. 56. 



O'strea cinnabarina, BORN ; Mus., 103. DILLWYN ; Catal., 256, No. 20. SCHKOET. ; 

 Einl., iii. 326, No. 9. 



Pecten Pealii, CONRAD ; Jlmcr. Mar. Conch. , 12, pi. 2, f. 2. 



