252 CALIFORNIA ACADEMY OF SCIENCES. 



figured is the type, which came from the lower San Pedro series at Deadman Island, 

 and is now in the United States National Museum. 

 Pleistocene. — San Pedro (Arnold). 



253. Trophon (Boreotrophon) scalariformis Gould. 



Plate VI, Fig. 10. 



Fiisus scalariformis Gld., Invert. Mass., p. 288, fig. 208. 



Trophon scalariformis Gld., Trvon, Man. Conch., Vol. II, p. 141, PI. XXXI, fig. 314, 18S0. 



Shell small, fusiform, spire elevated, subacute; whorls four or five, convex, crossed by about 

 thirteen prominent rounded ribs, most prominent in middle of whorl; body- whorl ventricose; 

 suture impressed, distinct; aperture broadly ovate; outer lip slightly effuse; inner lip curved, 

 smooth; columella long, rather narrow, curved, smooth; canal of medium length, narrow. 



Dimensions. — Long. i6mm. ; lat. 7.5 mm. ; body-whorl 10.5 mm.; aperture, including canal, 

 8 mm.; canal 3 mm.; defl. 44 degrees. 



Somewhat resembles T. multicostatus, but is distinguishable by lack of angula- 

 tion in whorls, longer columella and canal, but rather more ventricose body-whoid; 

 easily distinguishable from 7\ pedronna by more depressed aspect of .shell and lack 

 of spiral lines. Very faint spiral lines .sometimes visible. Specimens identified by 

 Dr. Dall. 



Rather common in lower San Pedro series, rare in Pliocene of Deadman 

 Island; found in the lower San Pedro series at San Pedro; and in the upper San 

 Pedro series at Crawfish George's. The specimen figured is from the lower San 

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



Living. — Circumboreal. Gulf of St. Lawrence. 



Pleistocene. — San Pedro (Arnold). 



Pliocene. — San Pedro (Arnold). 



254. Trophon (Boreotrophon) stuarti Sviiih. 



V\..\TK VI, Fic. 4. 



Trophon shiarli Smith, Proc. Zool. Soc, 1S80, p. 481, PI. XLVIII, fig. 6. 



Trophon orpheiis Old., Cpr., Brit. Assn Rept., 1863, p. 663 (in part). Trvon, Man. Conch., 



Vol. II, p. 139, PI. XXXI, fig. 310, 1880 (in part). Cooper, 7th Ann. Rept. Cal. St. 



Min., 1888, p. 268 (in part). Keep, West Coast Shells, p. 21, 1892 (in part). 



Shell of medium size, fusiform; spire elevated, acute; whorls seven, sharply angular, crossed 

 by nine to eleven frill-like varices which rise to sharp points on angle; whorls ornamented with two 

 to three sharp, spiral ridges, one of which revolves on angle; aperture semielliptical; outer lip 

 thickened, smooth within; inner lip incrusted, projecting; columella long, twisted, squamose; canal 

 long, narrow, slightly curved. 



Dimensions. — Long. 30 mm.; lat. 13 mm.; body-wliorl 2 mm.; aperture, including canal 

 16.5 mm.; canal 8 mm.; defl. 52 degrees. 



Distinguishable by prominent, frill-like varices and sharp spiral lines, which 

 give latticed appearance. Specimens identified by Dr. Dall. 



