196 AMERICAN MARINE CONCIIOLOGY. 



2. P. Islandicus, Miiller. Fig. 538. 



(Ostrea.) Zool. Danica, Prod. No. 2990. 1776. 

 Pecten Pealii, Conrad. Am. Mar. Conch., t. 12, f. 2. 1831. 



Shell oblong, orbicular, slightly oblique, valves nearly equal. 

 Surface covered with numerous, small, scaly, radiating ribs ; ears 

 unequal in size. Valves closed except at the notch. Color light- 

 orange to dark reddish-brown, frequently zoned or blotched on 

 the upper valve, lower valve lighter in color; white within, except 

 a large roseate spot near the beaks. 



Length 3.5 inches. 



New England. (Eur.) 



3. P. irradians, Lamarck. Fig. 530. 



Anim. sans Vert., vi. Pecten No. 37. 1819. 

 P. concentrieus, Say, Jouni. Philad. Acad., ii. 259. 1822. 



Shell orbicular, with from eighteen to twenty elevated, rounded 

 ribs, and numerous concentric wrinkles; inferior valve slightly 

 ventricose or gibbous towards the umbo ; ears large and nearly 

 equal. The upper valve is generally brown with pale zones, and 

 the lower valve yellowish or whitish with pale brown zones. 

 Diameter 2-3 inches. 



Whole Coast. 



The animal of the "scallop'' is eaten, and is comparable in 

 flavor to the lobster. The species is particularly numerous and 

 well-grown on the shores of Long Island and New Jersey, where 

 .the young shells, on a clear calm day, may be observed skipping 

 along to a considerable distance on the surface of the water; the 

 movement being accompanied by the noise occasioned by the rapid 

 closing of their valves. The adults are not active. 



4. P. dislocatus, Say. Fig. 540. 



Journ. Philad. Acad., ii. 260. 1824. 



Shell suborbicular, with twenty or twenty-two rounded ribs, and 

 very numerous concentric wrinkles; longitudinal stria 1 none; 

 whitish tinged with purple or yellow, with a few narrow, trans- 

 verse, interrupted and dislocated sanguineous, undulated lines, 

 and sometimes five or six pale-reddish, almost obsolete spots 

 .towards the margin ; ears subequal. 



Diameter 1.5 inches. 



North Carolina, southward*. 



