ARNOLD — THK PALEONTOLOCY AN'D STK.VTlii 1!A I'll V OK SAN I'EDUO. 251 



251. Trophon (Boreotrophon) multicostatus h'.fchsrhollz. 

 I'l.ATK VI, Fi(i. 9. 



Murex mullicoslnlus EsrH., Zool, Atlas, Vol. II. ]>. 11, PI. IX, f\^. 4, 1829. Kuster, Afiirex, 



p. 45, Pi. XVIII, fig.s. 5 ami 6, 1837. 

 TropAon Hiit//icos/afus KscH.. H. & A. An.VMS, den. Rec. Moll., Vol. i, p. 77. Cfk., Hilt. Assn. 



Rept., 1863, p. 663 (in part). Tkvon, Man. Concli., Vol. II, p. 141, Pi. XXXI, fig. 



316, 1880. CoopiiR, 7tli Ann. Kept. Cal. St. Min., 1888, p. 269 (in part). Keep, 



West Coast Shells, p. 21, 1892 (in part). 



Shell small, fusitbrni; wliorls five, anjjular aijove, with twelve to fourteen raised varices; no 

 spiral sculpture; aperture subeliiptical; outer lip not etifuse; inner lip smooth; canal sliort, slightly 

 curved. 



Dimensions. — Long. 10.5 mm.; lat. 4.5 mm.; body-whorl 7 mm.; aperture, including canal, 

 5 mm.; canal i mm.; defl. 40 degrees. 



The shell described is a small one. Distinguishable tfom T. gracilis by 

 having larger number of varices, less prominent varices, more slender shell, a less 

 effuse outer lip, and less sharply angulated whorls. Identified as "7'. iini/firostntiin 

 var.?" by Dr. Dall. 



Rare in the lower San Pedro series at Deadman Island, and in upper San 

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

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



Living. — Sitka to Monterey; circurapolar (Cooper). 



Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold). 



252. Trophon (Boreotrophon) pedroana, sp. nov. 



Plate VI, Fio. 12. 



Shell small, elongate-fijsiform, thin; spire elevated, acute; whorls six, convex, with very 

 slight angle about one-third width fi-oni posterior margin; body-whorl slightly ventricose; whorls 

 ornamented with about fourteen slightly raised, rounded transverse ridges, and two faint spiral 

 ridges, one of which is on the angle of whorl; suture deeply impressed, distinct; aperture semiovate; 

 outer lip thin, not effuse; inner lip smooth; columella long and slender, smooth; canal long, narrow, 

 nearly straight. 



Dimensions. — Long. 12 mm.; lat. 4.8 mm.; body-whorl 9 mm.; aperture, including canal, 

 7 mm.; canal 3 mm.; defi. 35 degrees. 



The thinnest, most delicate of the Trophons of thi.-< locality. Distinguishable 

 from var. pnecursor by thinness, less angulation of whorls, less prominence of 

 sculpture, and simple outer li[); distinguishable from 7'. sc.alariforiiux. by its thinness, 

 narrowness, and spiral lines; distinguishable from T. diapariliK Dall by smaller size, 

 more numerous whorls, and more prominent transverse sculpture. 



Pronounced a new species by Dr. Dall, wlio also says that it is near T. dis- 

 parilis, which has been dredged at Gray's Harl)or, Alaska. 



Rather common in the lower San Pedro series at San Pedro and Deadman 

 Island; found also in upper San Pedro series at Crawfish George's. The specimen 



