ARNOLD — THE PALEONTOLOGY AND STRATIGIIAPHY OF SAN PEDRO. 259 



and slender sliapo. The sculpture of this species is less prominent than on the other 

 species of this genus. 



Several specimens from the lower Ran Pedro series of Deadraan Island. 



Living. — Catalitia Island (Dall). 



Pleistocene. — San Pedro (Arnold). 



267. Ocinebra micheli Ford. 



Plate V, Fig. 15. 



Shell small, elongate-fusiform; spire elevated, acute; whorls five or six, strongly angulated 

 above, crossed by about nine prominent, rather sharp ridges, which are most prominent on angle; 

 anterior portion of whorl with four or five strong, squamose, raised lines, between which are numerous 

 squamose, incremental liruLx-; suture deeply appressed, distinct; aperture subovate; outer lip thick- 

 ened, smooth interiorly; inner lip incrusted, slightly raised; columella long, twisted, squamose; canal 

 long, narrow, nearly covered. 



Dimensions. — Long. 16 mm.; lat. 7 mm.; body-whorl 11 mm.; aperture, including canal, 

 8.5 mm.; canal 4 mm.; defl. 40 degrees. 



Roscmhles 0. perita somewhat, but is distinguishable by more slender form, 

 longer columella, and greater number of transverse ridges. Identified by Dr. Dall. 



One specimen from the upper San Pedro series at Crawfish George's, which is 

 figured, and is now in the collection of Delos Arnold. 



Living. — West Coast North America. 



Pleistocene. — San Pedro (Arnold). 



268. Ocinebra perita Hinds. 



Murex perilus Hds., Proc. Zool. Soc, 1843, p. 129; Voyage Sulphur, p. 9, PI. Ill, figs. 23, 24, 1844. 

 Ocinebra perita Hds., Trvon, Man. Conch., \'ol. II, p. 124, 1880. 

 Muricidea perita Hds., Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 252. 



Shell of medium size, fusiform; whorls five, sharply angulated, with about six or seven rather 

 sharp, transverse ridges which are most prominent on angle; surface ornamented with numerous 

 raised lines, with squamose, incremental lirulae in the interspaces; suture deeply appressed, wavy; 

 aperture subovate; outer lip thickened, denticulated; inner lip smooth, incrusted; canal long, 

 straight, narrow, sometimes covered; columella somewhat twisted, slightly widened; umbilicus 

 subperforate. 



Dimensions. — Long. 24 mm.; lat. 12.5 mm.; body-whorl 17 mm.; aperture, including canal 

 14 mm.; canal 6 mm.; defl. 60 degrees. 



Distinguishable from 0. barbarensis by less prominent points on angle of whorl, 

 and by less prominent spiral lines. Identified by Dr. Dall as probably 0. perita. 



Several specimens labeled by Dr. Dall as "0. interfossa, leaning toward 

 0. perita" had about one more transverse rib to the whorl than does the tj-pical 

 0. perita, the ribs were not .so prominent on the angle, but the spiral lines were 

 stronger than in the latter species. Comparing a series of both forms they are seen 



