398 



University of California Puhlications in Geology 



[Vol. 12 



Discussion. — The section of a mandible, no. 23195 (figs. 132, 140), 

 containing three premolars, and a second specimen representing M^, 

 no. 23215 (figs. 136a, 141), are but slightly worn, and illustrate the tall, 

 downwardly tapering crowns of the unworn stage. The is in about 

 the same stage of wear as that represented in the cross-section of Pj 

 of the jaw specimen. The teeth of an associated series, no. 23194 

 (fig. 133), are somewhat more worn, but generally similar to those of 

 the former specimen, no. 23195. The small molar tooth of no. 23194 

 is of considerable interest in showing the reduction in size of the 

 posterior portion of the series in this type. The small jaw fragment 

 containing Mj and Mg (fig. 139) is important in showing the relatively 

 small size of M;? of the worn teeth. 



141a 



141c 



141b 



140 



Figs. 140 to 141c. ?PIio}nppus edensis, n. sp. Lower cheek teeth of medium 

 size, lateral view, X Fig. 140, three premolar teeth, no. 23195 (for occlusal 

 view see fig. 132). Fig. 141a, molar, no. 23215 (for occlusal view see fig. 136a) ; 

 fig. 141b, no. 23352 (for occlusal view see fig. 137a); fig. 141c, Pj, no. 23194 (see 

 fig. 133 for occlusal view of series). Eden beds, California. 



Measurements 



Anteroposterior length of meta- 



No. 2 



3195 



No. 233.52 



Ps 



Pj 



Molar 



25.5 mm. 



25 mm. 



25 mm 



12.5 



14.5 



13.2 



12.9 



12.6 



12 



No. 23226 

 Molar 



25.2 mm. 



13.2 



12.3 



Large Lower Cheek Teeth, near ( ?)Pliohippus edensis 



subform b 



Material. — A second premolar, no. 23326 (fig. 144) ; premolars, nos. 23285, 

 23295 (figs. 146a-146&), 23212, 23223 (figs. 145a-145c, 145b) ; molars, nos. 23232, 

 23224, 23296a, 23294 (figs. 142a-142b, 143a, 143b, 143c) ; and last molar, no. 23288 

 (fig. 147). All in Univ. Calif. Coll. Vert. Pal., all Univ. Calif, loc. 3269'. 



