PECTENIDES. MOLLUSCA. PECTEN. 133 



upper valve moderately convex ; valves widel}- gaping near ilie 

 hinge, snrface everywhere sculptured with radiating, punctmed 

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

 somewdiat zigzag in their course ; these lines are crosi^erl 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, uii!i 

 minute radiating lines not corresponding to the exterior grooves. 

 Length 5 inches, height 5^ inches, breadth II inch. 



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

 valves, of a very large size and very solid, are occasionally tlnow n uo, 

 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, (tbo usual terminus for northern spcc'es) 

 for I have a fine specimen which was drawn U() alive, by a hoolc, off 

 Block Island. 



The general aspect of the lower valve is smooth ; nor do v.e sec 

 any thing like ribs on the upper surface. 



Pecten Isla'ndicus. 



Shell .sulj-orlicniar, reddish or orange-hrown ; ears unequal; 

 surface covered toith small.) crowded, irregulurhj disposed, ^cahj, 

 radiating ribs, which re-appear loithin. 



Figure 89. 



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



O'strea Islandicn, Mulleh; ZooL Don , Prod., No. 2990. Ljn.; /tri- Wfslrogoth., 

 200, t. 5, f. 7. Gmklin ; 3326. i\o. 55. Shaw ;. Zool. .Misc., .\xiii. I. 978, .087. 

 Fabr.; Fauna llrcenl., 415. Knoru ; Delices, 4'C., I. i. pi. B. f. o, 4. Listkr ; 

 Conch., t. 1057, f. 4. Guaf.t. ; Test., t. 73, f. R. Skba ; .\his., ii. t. 87. f. 7. 



Pecten Islandicus, Chemn.; Conch., vii. t. f)5, f. 015, (510 Thrton ; Conch. 

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

 ing ; Brit. .Intnl., 385, pi. 212,1". 1. Lahi. ; j^n. sans Vert., vii. 145. Say; 

 Amer. Conch., pi, 50. 



O'slrea cinnabaruiii, Born ; Mus., 103. Uillwvn ; Catal.,2o(), No. 20. Schkoet. ; 

 Einl., iii. 320, No. !). 



Pecten Pealii, Cokbad ; Amcr. Mar, Conch., 12, pi. 2, i'. 2. 



