ARNOLD — THU PALKONTOLOdY AND STKATKiUAPH Y OF SAN PEDIIO. 253 



Ivarc ill IMiocenc f»t I )(';iiliiiaii Islaiul and riiiiiii's Point; also reported from 

 lower S.iii IVdro series at Deadmaii Island. The specimen fifjiired is from the 

 Pliocene at Di-adman Tslaml, and is now in the collection of Delos Arnold. 



JAi-hiij.- Sitka (o Straits of Fuca; Wa.sliington (Cooper). 



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



Pliocene. — San Pedro (Arnold): San Dieijo w(dl (Dall). 



255. Trophon (Boreotrophon) stuarti .s'/k/V// var. praecursor, var. nov. 



I'l.ATK VI, Fuj. 5. 



Shell snuill, clonq^atf-fusitorm: spire elevated, acute; whorls .si.x or seven, angulated above, 

 crossed by^lbo^lt fifteen sharp varices, and with two shari> spiral lines; suture deeply impresseil 

 distinct; aperture subelliptical; outer lip effuse, smooth; inner li]) smooth; columella long, straight, 

 nearly smooth; canal long, narrow, very slightly curved. 



Dimensions.— \Mn^. 15 mm.; lat. 5.5 mm.; botly-whorl 10 mm.; aperture, including canal, 

 8 mm.; canal 4.2 mm.; defl. 35 degrees. 



I)istin_n'iii.slialde from T. stnartl by smaller size, less prominent transverse 

 frills and spiral lines, and slenderer form; distinguisliable from 7\ dit^pnrilis by much 

 more sharply defined sculpture and more angiilated whorls. Pronounced var. prre- 

 cui-snr of .7'. stiiard by Dr. Dall. Type from Pliocene of Deadman Island. 



Not uncommon in Pliocene and lower San Pedro series of Deadman Island. 

 Found also in IMcistocene at i)ath-house, Santa Barbara. 'I'he specimen figured is 

 the ty]tc, wiiicli was found in the Pliocene of Deadman Island, and is now in the 

 collection of Delos Arnold. 



Pleistocene. — San Pedro (Arnold). 



Pliocene. — San Pedro; Santa Barbara (Arnold). 



256. Trophon (Boreotrophon) tenuisculptus Carpenter. 



Troplion tcnuisculplus Cpr., Ann. & Mag. Nat. Hist., 3rd Ser., Vol. XVII, 1866, p. 277. Gabb, Pal. 

 Cal., Vol. II, p. 70, 1869. Tryon, Man. Conch., Vol. II, p. 139, PL XXXIII, fig. 359, 

 1880. Cooper, 7tli Ann. Rept. Cal. St. Min., iSSS, p. 268. 



.Slifll small, fusiform; whorls live, angulated above, forming a slightly sloping, tabular band 

 above; ornamentations of numerous transverse ridges and several spiral lines; suture deeply 

 impressed; aperture elliptical; outer li[) thin: inner lip incrusted, smooth; canal narrow; columella 

 long, twisted. 



Dimensions of a Young Specimen. — Long. 14.5 mm.; lat. 6.1 mm.; body-whorl 10 mm.; 

 aperture and canal S mm.; canal 4.5 mm. ; defl. 50 degrees. 



Distinguishable by numerous transverse ridges, which are more numerous 

 than in any other member of this genus found in this locality. Type of species 

 from Pleistocene of Santa Barbara. Specimen identified by Dr. Dall. 



Rare in Pliocene of San Pedro district. 



Pleistocene. — Santa Barbara (Carpenter). 

 Pliocene. — San Pedro (Arnold). 



