ARNOLD — THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDRO. 215 



A slender, deeply sutured form, with a comparatively long canal; these 

 characteristics distinguishing it from others of the genus. Specimen identified by 

 Dr. Dall. ' • 



Rare in Pliocene and lower San Pedro series of Deadman Island; one 

 specimen from each horizon. The specimen figured is from the Pliocene of Dead- 

 man Island, and is now in the collection of Delos Arnold. 



Living. — West Coast. 



Pleistocene. — San Pedro (Arnold). 



Pliocene. — San Pedro (Arnold). 



192. Mangilia striosa 0. B. Adams. 



Pl.ATK IX, FiC. .s. 



Mangilia striosa C. B. Ads., Ann. N. Y. Lye. Nat. Hist., Vol. V, 1852, p. 147. Tryon, Man. 

 Conch., Vol. VI, p. 249, PL XXXIV, fig. 96, 1884. Williamson, Proc. U. S. Nat. 

 Mus., Vol. XV, p. 208, 1892. 



Shell small, elongate-fusiform; spire much elevated; ape.x acute; whorls six, subangular, 

 with numerous fine, slightly wavy transverse ridges, which become obsolete at the sutures; spiral 

 sculpture nearly obsolete; suture very deeply depressed, giving a rather frail appearance to the 

 spires; aperture narrow, elliptical, tapering anteriorly to a short, truncated canal; posterior sinus 

 small; outer lip thin, simple, arcuate; columella smooth; straight on anterior portion. 



Dimensions. — Long. 9.2 mm.; lat. 3 mm.; body-whorl 5.2 mm.; aperture 4 mm.; defl. 

 22 degrees. 



This species is distinguishable by its numerous fine, transverse ridges, deep 

 suture, subangular whorls, and slender form. Resembles M. sciilpttiraia somewhat in 

 outline, but has less angular whorls and more numerous, finer ribs. Distinguishable 

 from 2/. oldrnijdi by the angle being nearer the middle of the whorl, the ridges being 

 finer, the pillar .shorter, and the suture deeper. Specimens identified by Dr. Dall. 



Rare in upper San Pedro series of San Pedro and Los Cerritos. Found also 

 in Pleistocene at Spanish Bight, San Diego. The specimen figured is from the upper 

 San Pedro series at Los Cerritos, and is now in the collection of Delos Arnold. 



Living. — Panama (Carpenter): San Pedro (Williamson). 



Pleistocene. — San Pedro; San Diego (Arnold). 



Subgenus Taranis Jeffreys. 



Shell minute, cancellated; whorls angulated, slightly exserted at base; aperture pyriform; 

 outer lip thin, simple; sinus obsolete; canal short. 



l^arnnis morchii Malm, is a characteristic species. 



193. Mangilia (Taranis) strongi, sp. nov. 



Plate IX, Fig. 7. 



Shell small, elongated; spire elevated; apex mammilliform; whorls six, angulated near 

 middle, upper surface concave, lower surface convex; two strong spiral ridges, one on angle, the 



