ARNOLD — THE PALEONTOLOCY AND STUATKlUArHY OF SAN I'EDKO. '2'>\ 



251. Trophon (Boreotrophoni multicostatus /Cxclisihullz. 



I'LATK. VI, l>'l(i. !). 



Murex multicostatus Esru., Zool. Atlas, Vol. II, \>. 11. I'l. IX, fijr. 4, 1.S29. Kuster, yl///r<'jr, 



p. 45, PI. XVI II, figs. 3 and 6. 1837. 

 Trophon viii/tkostatiis P^scH., H. & A. Adams, ("k-ii. Ric. Moll., XOJ. 1. p. 77. Cpk., Hrit. Assn. 



Rcpt., 1863, p. 663 (in part). TkVON, Man. Comii., Vol. II. p. 141, PI. XXXI, fig. 



316, 1880. Cooi'Kk, 7th Ann. Kept. Cal. St. Min., 1S88, p. 269 (in pari). Keep, 



West Coast -SliL-Jls, p. 21, 1892 1 in part). 



Shell small, rusitonn; whorls five, angular above, with twelve to fourteen raised varices; no 

 spiral sculpture: aperture subclliptical; outer lip not effuse; inner lip smooth; canal short, slightly 

 curved. 



Dimnisions. — Long. 10.5 mm.; lal. 4.5 mm.; body-whorl 7 mm.; aperture, iiuluding canal, 

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



Till' sliell (lescfil)e(l is a small niio. Distiii,niiislial)l(! t'foiii T. grari/l:< by 

 having larger iitiiuber of varices, less pi-oiiiiiieiit varices, inore slender shell, a less 

 efftise outer lip, and less sharply aiigulated whorls. Identified as "7'. multicostntiis 

 var.?" by Dr. Dall. 



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

 Pedro series at Han Pedro. The specimen fignred is frotn the lower San Pedro series 

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



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



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



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



Pl.vtk VI, Fic. 1-2. 



Siiell small, elongate-fusiform, thin; spire elevated, acute; whorls si.K, convex, with very 

 slight angle about one-third width from 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.; detl. 35 degrees. 



The thinnest, most delicate of the Trophoitx of llii- locality. Distinguishable 

 from var. prcnoirsor by thinness, le.^s angulation of whorls, less prominence of 

 sctilpture, and sitnple outer li[); distingtiishable from 7'. scdlarifonnis by its thinness, 

 narrowness, and spiral lines; distingiiisiialile from 7'. dif^p'd'i/iK Dall by smaller size, 

 more numerous whorls, and mure pr((miii(iil transverse sculpture. 



Pronounced a new species liy Dr. Dall, who also says that it is near ?'. dis- 

 p(irili!<, which has been dredged at (iiay's Ilariior, 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 



