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 tliem, 

 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. Hmge 

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

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

 minute radiating lines not corresponding to the exterior grooves. 

 Length 5 inches, height 5| inches, breadth H inch. 



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

 valves, of a very large size and very solid, are occasionally throv/n 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 IMaine 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, oflT 

 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. 



*S'//e// sub-orhicnlar , reddish or orange-brown; ears unequal; 

 surface covered ivith small, crowded, irregularly disposed, scaly, 

 radiating ribs, wMch re-appear toithin. 



Figure 89. 



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



O'strea Islandica, Muller; Zool. Dan., Prod., No. 2990. Lin.; Iter iVestrogoth., 

 200, t. 5, f. 7. Gmelin ; 3326. No. 55. Shaw ;. Zool. Misc., xxiii. t. 978, 987. 

 Faep..; Fauna Grcenl., 415. Knorr ; Delices, ^'C, t. i. pi. B. f. 3, 4. LiSfER ; 

 Conch., t. 1057, f. 4. Gualt. ; Test., t. 73, f. R. Seba ; Afus., ii. t. 87, f. 7. 



Pecten Islandicus, Chemn. ; Conch., vii. t. 65, f. 615, 616. Turton ; Couch. 

 Diet., 258. Brit. Biv., 216. Deshayes ; Encyc. Jrlith., Vers, iii. 724. Flem- 

 ing ; Brit. Jlnim., 385, pi. 212, f. 1. Lam.; Jin. sans Vert., vii. 145. Say; 

 Amer. Conch., pi. 56. 



O'strea cinnabarina, Born ; Mas., 103. Dillwyn : Catal., 256, No. 20. Schroet. ; 

 Einl., iii. 326, No. 9. 



Pecten Pealii, Conkad ; Amer. Mar. Conch., 12, pi. 2, f. 2. 



