PELECYPODS 437 
ered with a multitude of erect scales. The ribs persist upon the interior of 
the shell. The “ears” are unequal in size. The coloris light orange to 
reddish-brown, with zones 
of darker and richer col- 
or. One valve is flatter 
than the other and more 
lightly colored. Greatest 
length about three inches; 
height three and a half 
inches. Thisisa Northern 
shell, belonging to the 
waters of Newfoundland, 
but its valves are fre- 
quently cast upon the New f 
England beaches. 
- trradians. The § 
common — shallow-water 
species of the Atlantic 
coast. This exceedingly 
abundant species does 
not range north of Bos- 
ton, but finds an exten- 
sive habitat to the south. 
Its metropolis is Cape 
Cod, Long Island Sound, 
and the Jersey coast Pecten islandicus. 
waters. This is the true 
scallop of the Boston and New York markets. Only the adductor 
muscle is eaten. In this species there is not so marked a difference in 
the convexity of the two valves. There are about twenty elevated and 
rounded ribs, the spaces between them being also rounded. The color 
is variable, from a blackish horn to ashengray. The “ears” are equal; 
the interior is shining, and grooved to correspond with the external ribs. 
Length two and three fifths inches, height two and a half inches. On 
clear, calm days the immature individuals of this species may often be 
seen in shallow water disporting themselves most gaily, skipping about 
and snapping their valves in great glee. Their mantle margins are very 
ornate in scarlet or orange, with rows of bright-blue eyes. Care must 
be taken in handling scallops, especially the large P. magellanicus, for a 
finger caught between the valves will be badly bruised. 
P. dislocatus. South of Hatteras this species takes the place of its 
Northern relative, P. irradians. It is somewhat more globular and per- 
haps not quite so large, but the resemblance between the two species is 
very marked. It has from twenty to twenty-two rounded ribs, with very 
numerous concentric wrinkles between them. In coloritis white, tinged 
with purple or yellow, with occasionally a system of blood-red lines 
crossing the ribs transversely. The diameter is about one and a half 
inches. This species has the same playful habits as P. irradians, and is 
not at all easy to capture. When pursued it dives into the mud, and sets 
up such a commotion by the spasmodic opening and shutting of its 
valves that the water at once becomes roiled, and the scallop is safely 
hidden in 1ts murky depths. . 
