PANAMIC-PACIFIC PELECYPODA 165 



sometimes mottled with white and under a lens seen to be sprinkled with 

 small white dots or streaks. Interior generally white or slaty gray. Anterior 

 right ear with a deep, byssal notch. 



Common along the beaches of northwestern Peru. 



Range — Gulf of California to northern Peru. For northern records, the 

 writer is referred to Hertlein and Strong. Panama: Panama City; Guanico. 

 Canal Zone: Venado Beach; Palo Seco. Ecuador: Santa Elena; Manta; 

 Esmeraldas. Peru: Tumbez; Zorritos; Mancora; Lobitos; Negritos; Paita. 



Subgenus LEPTOPECTEN Verrill, 1897 



Type species by original designation, Chlamys monotimeris (Conrad), 

 [C. latiaurita (Conrad)]. [As a subgenus of Chlamys.'] 



Shell small, thin or of medium weight, with nearly equal and similar 

 sculptured valves of slight convexity, that of the right valve is a trifle less. 

 Sculpture consists of narrow, rounded ribs, their interspaces flattened and 

 as wide or wider, the whole crossed with fine or coarse, concentric threads, 

 and below these fine radial threads. Ears subequal, except the right an- 

 terior which is cut into by a deep byssal notch, bordered on the disk side by 

 several, sharp, pectinate teeth. 



Aeqaipecten (Leptopecten) Telero (Hertlein) Plate 21, figures 1-la 



Pecten (Leptopecten) velero Hertlein, 1935, Proc. California Acad. Sci., ser. 4, vol. 21, 

 No, 25, p. 316, pi. 19, figs. 13, 1+ Bahia Honda, Veragua, Panama in 3 to 9 

 fathoms. — Hertlein and Strong, 1946, Zoologica, vol. 31, pt. 2, p. 60. 



The shell is small, thin, flattened, the left valve noticeably inequi- 

 lateral, the right valve less so, and sculptured with low, rounded or flattened 

 smooth or slightly scaly ribs, generally about 15 in the left valve, and 

 about 13 in the right; in the left valve, usually every third rib is somewhat 

 larger than the others, sometimes also in the right. Spaces between the ribs 

 on the umbones are as wide as the ribs and usually strongly sculptured 

 with coarse cross threads; this sculpture may extend over most of the 

 surface but usually the interspaces ventrally are smooth or nearly so. 

 Ears are large, the anterior, right ear elongated and provided with a deep, 

 byssal notch bordered below by small pectinate teeth. Ears are usually well 

 sculptured, the right anterior ear with strong ribs. Color is usually a purplish 

 red, the left valve darker and often maculated, the right valve lighter, 

 sometimes white or yellow. Hinge line long, minutely wrinkled or striated. 



Length 11.4 mm., height 11.3 mm. left valve. 



Length 11.2 mm., height 11.3 mm. right valve. 



A relatively small species distinguished from the young of A. tum- 

 bezensis by its thinner shell and stronger sculpture, the umbonal ribbed 

 interspaces are heavily cross-threaded. Widely distributed but easily 

 overlooked because of its small size. 



I am indebted to Dr. L. G. Hertlein of the California Academy of 

 Sciences for the opportunity of examining typical specimens of this species. 



Range— Mt\\co to northern Peru. Mexico, El Salvador, and Nicaragua, 

 see Hertlein and Strong; Panama: Bahia Honda (Hertlein and Strong); 

 Concepcion beach near Las Tablas. Peru: Mancora. 



