168 PROCEEDINGS OF THE NATIOXAL MVSiEVM. vol.. 37. 



surface with revolving striae; spire acute, shorter than the body 

 whorl; color white, gray, or ohvaceous, with chocolate clouding 

 especially on the back of the body whorl, which is sometimes nearly 

 all chocolate colored; length 18 mm. 



These small shells have no economic value in themselves; but they 

 drill the very young 03"sters when about 10 mm. in diameter, pierce 

 the thin shell, and suck the juices of the animal. If very numerous 

 they might be a serious detriment to the maintenance of growing 

 oysters. 



ASTYRIS UNICOLOR Sowerby. 



Columbella unicolor Sowerby, Proc. Zool. Soc. of London for 1832, p. 119. — 

 Reeve, Conch. Icon., Columbella, pi. 19, fig. 105. 

 Dredged in Callao harbor, in 2J fathoms, near San Lorenzo Island. 



Distribution. — From Chiloe Island northward through Chile, Peru, 

 and the Galapagos Islands. 



Shell very small, ovate, smooth with revolving strife near the 

 canal; color chocolate or chestnut brown, with or without a lighter 

 band revolving on the periphery; aperture brownish within; outer lip 

 and pillar with a few obscure denticles in the adult; length about 

 12 mm. 



This small shell, remarkable for its wide geographic range, has no 

 economic relations. 



ALECTRION (HIMA) DENTIFERUS Powys. 



Nassa dentifera Powy.s, Proc. Zool. Soc. of London for 1835, p. 95.— Orbiony, 

 Voy. Am. Mer., vol. 5, 1841, p. 432, p'. CI, figs. 22-23. 

 Dredged in about 9 fathoms, muddy bottom, in Ancon Bay. 



Distrihution. — Coasts of Chile and Peru, from Valparaiso north- 

 ward to Panama. 



Shell small, turrited, rather thin, obscurely reticulately sculptured, 

 chocolate brown, inside and out, with occasionally a paler peripheral 

 spiral band; outer lip sharp, thin, in the adult having an obscure 

 varix behind it; the sculpture variable in strength; length 20 mm. 



This small and unattractive species has no economic importance. 



CONCHOLEPAS CONCHOLEPAS Bruguiere. 



Plate 22, fig. 1. 



Buccinum concholepas Bruouiere, Encycl. Meth., 1789, p. 252. — Dillwyn, Rec. 



Sh., vol. 2, 1817, p. 611. 

 Concholepas peruvianus Lamarck, An. s. Vert., vol. 7, 1822, p. 252. — Tryon, Man. 

 Conch., vol. 2, 1880, p. 199, pi. 1G2, figs. 314-316. 

 Pata de burro, of the southern region. Common on some of the rocks some yards 

 from sliore and at or below low-water line. 



Distribution. — Chincha Islands. Mollendo, and south to the Magel- 

 lanic region. Also northward, according to E. von Martens, to the 

 west coast of Mexico. 



