TRIBE PECTINIDES. 269 
obliquely plicated ; with from twelve to fourteen somewhat depressed 
rounded ribs which are broad and sulcated, yellowish white or yel- 
lowish brown, angularly spotted (chiefly at the umbones) with red 
or brown. 6..65. England, Mediterranean. The common Scallop 
P. Simiuis Sow. Th. f. 116,7. Closely resembling the last, but 
the ribs in the concave left valve more elevated, in the smoothish 
right valve more grooved. 32..3, England.? 
P. Jacopxus* Chem. f. 588.— Lam. 3.—Fhillippi. p. 78.—Poli. 
t. 27. f..1,2, 3.—E. t. 209. f. 2.—Sow. Th. f. 107, 108, 153.—Os- 
TREA J. Lin. 1144,.—ZLast. t. 165.—W.t. 11. f. 2. Suborbicular, 
spread at the sides, rather depressed ; upper valve concave near the 
umbo,the sides elevated; ears broad rectangular concave and grooved 
near the margin; ribs fourteen to sixteen, in the left valve much 
elevated rounded concentrically striated, in the lower valve much 
elevated, quadrate, with strong radiating moniliform sulci, the 
interstices concentrically striated; yellowish white or yellowish 
fuscous, angularly spotted with red or fuscous. 6.. 63. Lngland? 
Mediterranean. 
P. Laqueatus Sow. Th. t. 15. f 101. Rounded; right valve 
with seven broad somewhat smooth subquadrate flattened ribs, which 
are obsoletely and radiatingly grooved ; the interstices narrow, flat: 
white, tinged with purple at the umbo. NW. W. America. 35. 4s 
The other valve is unknown. 
P. Mepius Lam. 2.—E. vol. 3. p. 715,— Sow. Th. f. 102, 3,4. 
—Ch. f. 586,7,8.? Suborbicular, rather depressed, smooth ; 
flattened valve rather concave near the umbone, sides slightly ele- 
vated, with fourteen narrow ribs which are angulated at the sides 
and flat; ears equal, broad, concave and grooved near the margin: 
ribs in the convex valve sixteen, broad, divided, somewhat rounded, 
depressed ; yellowish white or fuscous with red spots, red with 
either white spots or purple bands. 3,3..2,8. WW. Indies. 
P. Sutcicostatus Sow. Th. f. 35,6. Rounded, radiately sul- 
cated, rather ventricose ; ears wide, concave, striated; theribs twelve 
in the upper valve, (which is pale fawn with angulated streaks of 
red,) elevated, rather square and sulcated ;in the purple lower valve, 
rounded and striated, with scarcely any interstices; interstices of 
the left valve sulcated and as wide as the ribs. 14,, 13 
P. Susviripis Sow. Th. f. 165,6. Suborbicular, subventricose ; 
upper valve concave near the umbones, the sides elevated; ears 
broad rectangular, concave and grooved near the margin, the thirteen 
central ribs rounded smooth and elevated in the upper valve, the 
lateral ones smaller; in the lower valve obsoletely grooved, the 
interstices concentrically striated ; upper valve greenish brown, 
lower valve white, yellow at the umbo, and brownish in the middle. 
2..21 Allied to Jacobeus. 
