ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 253 



Rare in Pliocene of Deadman Island and Tiniin's Point; also reported from 

 lower San Pedro series at Deadman Island. The specimen figured is from the 

 Pliocene at Deadman Island, and is now in the collection of Delos Arnold. 



Living. — Sitka to Straits of Fuca; Washington (Cooper). 



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



Pliocene. — San Pedro (Arnold): San Diego well (Dall). 



255. Trophon (Boreotrophon) stuarti Smith var. praecursor, var. nov. 



Plate VI, Fig. 5. 



Shell small, elongate-fusiform; spire elevated, acute; whorls six or seven, angulated above, 

 crossed by about fifteen sharp varices, and with two sharp spiral lines; suture deeply impressed 

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

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



Dimensions. — Long. 15 mm.; lat. 5.5 mm.; body-whorl 10 mm.; aperture, including canal, 

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



Distingnishable from T. »tuarti by smaller .size, le.ss prominent transverse 

 frills and spiral lines, and slenderer form; distingni.shable from T. ditiparilis by much 

 more sharply defined sculpture and more angulated whorls. Pronounced var. jjrre- 

 cursor of 7\ studiil by Dr. Dall. Type from Pliocene of Deadman Island. 



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

 Found also in Pleistocene at bath-house, Santa Barbara. The specimen figured is 

 the type, which 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. 



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

 Cal., Vol. II, p. 70, 1869. Trvon, Man. Conch., Vol. II, p. 139, PI. XXXIII, fig. 359, 

 1880. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 268. 



Shell small, fusiform; whorls five, angulated above, forming a slightly sloping, tabular band 

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

 impressed; aperture elliptical; outer lip 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 8 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). 



