CLASS PELECYPODA 
57 
SECTION PATINOPECTEN Dali, 1898. 
Pecten caurinus Gould, 1850. 
Plate 6, fig. 1 and Plate 4, fig. 1. 
Proc. Boston Soc. Nat. Hist., 3 :345. Arnold, Tert . Pectcns Cal.; pi. 38, 39. 
Shell large, rather thick, nearly circular, a little inequilateral, and 
slightly oblique; the valves unequal; the upper valve is purplish-red, 
slightly convex marked with delicate lines of growth, and with 20 or 
more slightly raised, rounded ribs, about half as wide as the interspaces, 
diminishing toward the sides, and sometimes nearly subdivided by one 
or more furrows; the lower valve more convex, white, and becoming 
reddish toward margins, and with about 21 ribs, equal to the interspaces, 
elevated, flattened at summit, and with the sides vertical, and even 
incumbent; sometimes there are obsolete intervening ones. The ears are 
transverse, nearly equal, the anterior ones faintly rayed with scattered 
lira; the sinus broadly rounded; beaks roseate, compressed; interior milk- 
w r hite, with a silky lustre, and roseate marginal line. Length, 3 ; height, 
2J4 ; diameter, 1 poll.* (Gould.) 
Type in Boston Soc. Nat. Hist. Type locality, Port Townsend, 
Admiralty Inlet. 
Range. Wrangell, Alaska, to Siletz Bay, Oregon. 
SECTION LEPTOPECTEN Verrill, 1897. 
Pecten latiauritus Conrad, 1837. 
Plate 22, fig. 2. 
Jour. Acad. Nat. Sci. Phila., 7:238; pi. 18, fig. 9. 
Shell inequilateral, thin, compressed; ribs 14, flattened on the back, 
slightly sulcated; interspaces striated; ears very wide, unequal, both 
acutely angulated at the extremity; color reddish brown and white, varie¬ 
gated or spotted. Length, 30; height, 34; diameter, 6 mm. (Conrad.) 
Type in Phila. Acad. Sci. Type locality, near San Diego, California. 
Range. Monterey, California, to the Gulf of California. 
Pecten latiauritus monotimeris Conrad, 1837. 
Plate 40, figs. 1, 2. 
Jour. Acad. Nat. Sci. Phila., 7 :238; pi. 18, fig. 10. 
Shell ovate, oblique, thin, compressed, with concentric striae; ribs 13, 
rounded; ears subequal; color brown, with white stripes and spots. 
Length, 20; height, 19; diameter, 9 mm. (Conrad.) 
Type in Phila. Acad. Sci. Type locality, San Diego, California. 
Range. Monterey, California, to the Gulf of California. 
* Poll, equals an inch. 
