AliNOI.Ii niK I'AI.KOSTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 249 



Tlie piovailiiii^- type of tliu San Pcdio fossil specimens does not correspond 

 exactly lo any of the ik\scri[)tions of tiie living varieties of this species as {^iven by 

 Dr. I>all ill the paper cited above. It comes nearest to var. uiiispinosn, differing 

 iroin that fiiini liy having a straight canal. 'I'lic name vnv. jileistocenensis is suggested 

 for the San I'cdro fossil foian. 



liare in the u[)per San Tedio series of San I'edro; one specimen from lower 

 San Pedro series at Deadman Island. Fonnd also in the Pleistocene at Twenty- 

 sixtii Street, San Diego. The specimen figured is fium the upper San Pedro series 

 at San Pedro, and is now in the collection of Delos AiiinM. 



JAcing. — California to \'cne/.iiela (J)all). 



Pki»tocene. — San Petiro (Arnold): San Diego (Dall; Cooper; Arnold): 

 Pacific coast of Lower California; head of tlic(!ulf of California (Dall). 



248. Eupleura muriciformis var. curta, var. iiov. 



Pl.ATK VIII, I'u:. 9. 



Shell small, broadly fusilbrm; whorls I'uur, angular, Hat above, convex below; two sharp 

 spiral ridj>es on upper whorls, si.x on body-whorl correspondinjj to obsolete spines on varix; one 

 prominent varix on body-whorl, other varices obsolete; whorls crossed by prominent, narrow, 

 routided ridije.s, of which there are twelve on the penultimate whorl; aperture elliptical; outer lip 

 thickened by a row of six denticles; inner lip smooth, projecting; canal short, narrow. 



Dimensio>is. — Long. 15 mm.; lat. 10 mm.; body-whorl 11 mm.; aperture, including canal, 

 9.5 mm.; canal 2.2 mm.; defl. 65 degrees. 



DifTers from /:,'. iituricifoni/ix in having ob.solete varices, transverse ridges 

 in.stead of nodes, inncii shorter canal, and in general much stronger sculpture. 



The type, which is figured, is from the upper San Pedro series at San Pedro, 

 and is now in the United States National !\riiscum. 



Pleistocene. — San Pedro (Arnold). 



Genus Trophon Montforl. 



Varices numerous, lamcllitorm or laciniated; s[)ire prominent; aperture ovate; canal open, 

 usually turned lo llic Icit; shell uhitc, often dark colored within the a])ertuie. 



2ropho7i clntliniliif^ Linn, is a characteristic species. 



Subgenus Boreotrophon Fischer. 



249. Trophon (Boreotrophon) cerritensis, sp. uov. 



Platk VI, Fig. 6. 



Shell of medium size, elongate-fusiform, heavy; whorls six, angular, with angle in middle, 

 crossed by about eighteen strong, tran.svcrse ribs; lower portion of whorls ornamented with two or 

 three strong, spiral ridges, one of which is on the angle, the two systems of ridges giving a can- 

 cellated surlace; body- whorl and columella cancellated; suture deeply impressed, distinct; aperture 



( 3.> ) Marv h JJ. 1903. 



