166 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. 37. 
OLIVELLA COLUMELLARIS Sowerby. ‘ 
Oliva columellaris SowpRByY, Tankerville Cat., App. 1825, p. xxx1v.—REEVE, 
Conch. Icon. Oliva, 1850, fig. 62. 
Beach of Sechura Bay, near Matacaballa. 
Distribution.—Central American coast, Panama and southward to 
Paita and Sechura Bay. ; 
Shell small, polished, spire acute, short, last whorl expanded in 
front, feebly axially striated; pale grayish or lead color, with a 
heavy whitish body callus, and usually a yellowish spiral band at the 
middle of the whorl and behind the suture. There is a single strong 
plait on the anterior edge of the pillar; interior of the aperture pur- 
ple, showing one paler band. The animal, unlike that of Olhwa, 
possesses a small horny operculum. These shells in prehistoric times 
were used as beads. 
OLIVELLA SEMISTRIATA Gray. 
Oliva semistriata Gray, Zool. Beechey’s Voy., 1839, p. 130, pl. 36, fig. 10. 
Dredged in Sechura Bay, in about 5 fathoms, west of Matacaballa. 
Mstribution.— Gulf of California and southward: to Sechura Bay. 
This species is very similar to the last, but has a proportionately 
longer spire and is less compressed in front. Neither of the species 
has any present economic value. 
MARGINELLA CURTA Sowerby. 
Marginella curta SowERBY, Proc. Zool. Soc. of London for 1832, p. 105; Thes. 
Conch., vol. 1, p. 397, pl. 76, figs. 88, 89. 
Dredged in Sechura Bay, between Bayovar and Matacaballa; found also at the 
Chincha Islands and Lobos de Aiuera Island. 
Mstribution.—From Panama southward to Iquique, Chile. 
Shell small, polished, of a purplish brown, the spire very short, the 
aperture narrow, nearly as long as the spire, the pillar with four 
well-marked plaits; the surface without sculpture except faint incre- 
mental lines. 
This species has no present economic value, but the prehistoric 
tribes ground off the apex of the spire, strung the shells on a cord, 
and used them for beads. 
MITRA ORIENTALIS Gray. 
Mitra orientalis Gray, in Griffith’s Cuvier, 1834, pl. 40, fig. 5. 
Taken on rocks of beach at Ancon; one dilapidated specimen. 
DMstribution.—V alparaiso, north to Ancon. 
Shell elongate, turrited, covered with a thick black periostracum 
which in drying peels off, coarsely feebly spirally striated; the last 
whorl longer than the spire; aperture about half as long as the shell, 
