370 AXEL A. OLSSON 



Semele venusta (Reeve) Plate 66, figures 1, la 



Amphidesma venusta Reeve, 1853, Conch. Icon., vol. 8, Amphidesma, pi. 1, fig. 3 West 

 Colombia.— A. Adams, 1854, Proc. Zool. Soc. London for 1853, p. 96. 



Semele venusta (Reeve), Hertlein and Strong, 1949, Zoologica, vol. 34, pt. 4, No. 19, pp. 

 248, 249, pi. 1, fig. 13. 



Shell of medium size (31 mm., or less), obliquely oblong-elliptical, 

 moderately convex, the beaks high, placed a little behind the middle, the 

 anterior side hence much longer, its dorsal margin straight. Posterior side 

 wide, its surface impressed. Sculpture is produced by small, rounded, close- 

 set, concentric riblets between grooved spaces; on the right valve, the riblets 

 may divide as they pass over the posterior slope, while on the left valve, 

 the riblets in the same position are weak or obsolete. The pallial sinus is 

 large, and reaches almost to the anterior adductor scar. The surface color 

 is usually white or pale violet rayed with yellow; interior white or stained 

 lightly with purple. 



Length 30.8 mm., height 24 mm., diameter 12.3 mm. Palo Seco, Panama 

 Canal Zone. 



Much like S. guaymasensis, with which it often occurs, but is longer 

 and lacks the radial grooves on the dorsal submargins. 



Range — Coast of Mexico to northern Peru. Mexico: Santa Cruz and 

 Tangola-Tangola Bays (Hertlein and Strong). Panama: Pearl Islands. 

 Panama Canal Zone: Palo Seco: Ecuador: Manta; Puerto Callo. Peru: 

 Punta Picos. 



Semele margarita, new species Plate 66, figure 3 



Shell relatively small, oblong, the beaks placed a trifle anterior of the 

 middle, the two ends evenly rounded, depressed, rather solid. Dorsal areas 

 not defined. Sculpture is coarsely cancellate, consisting of strong, evenly 

 spaced concentrics, crenulated by irregular radial lines. Color white or 

 weakly tinted with red along the dorsal margin. 



Length 14.1 mm., diameter 11.5 mm., diameter of a right valve 2.4 mm. 

 Holotype, PRI 25935. 



Somewhat similar to S. pacifica but with coarser cancellation and higher, 

 more ovate shape. 



Jlange — Panama. Panama: West side of Rey Island, Pearl Islands. 



EXTRALIMITAL SPECIES 



Semele medlamericana Pilsbry and Lowe=S, proficna (Pulteney) (reticulata 



Reeve) 



Semele medlamericana Pilsbry and Lowe, 1932, Proc. Acad. Nat. Sci. Philadelphia, p. 

 92, pi. 12, figs. 1, la, 2. 



Described as a Pacific species from Nicaragua (collected by MacNeil), 

 the specimen evidently came from the Caribbean coast. Holotype, ANSP 

 53295. 



Genus CUMEfGL/l Sowerby, 1833 



Type species by subsequent designation, Gray, 1847, C. lamellosa 

 Sowerby. Panama-Pacific faunal province. 



Shell free or as a nestler in crevices or abandoned burrows, sometimes 



