494 University of California Publications in Geology [Vol. 10 



A third or fourth superior tooth (fig. 12), no. 19860, does not 

 differ essentially in general shape from the superior tooth in no. 19864. 

 The triturating surface is worn more deeply to a median valley, while 

 the posterior as well as the anterior border is beveled. The crown of 

 the tooth is also longitudinally concave along the outer side. As 

 in N. shastense this tooth possesses a concave posterior face, the inner 

 and outer faces are grooved, and the anterior face is broadly convex. 

 The tooth narrows toward the outer side. 



The last upper tooth (figs. 14a, 14&) no. 21473, is wider trans- 

 versely than most corresponding teeth from Rancho La Brea, being 

 slightly larger in this direction than specimen 634 in the collections 

 of the Museum of History, Science and Art of Los Angeles. It is 

 relatively thinner anteroposterior^ than specimens from the asphalt 

 beds. The shja^eof M- in the Rancho La Brea formes remarkably 

 nwre^tronglyltw is directed more 



anteriorly and with a better defined longitudinal groove. The anterior 

 face is convex toward the outer side and slightly concave toward 

 the inner. It approximates the posterior face more closely toward 

 the inner side than in M- from Rancho La Brea. The posterior face 

 is deeply concave transversely. The triturating surface is beveled 

 anteriorly. The crown of the tooth is longitudinally concave anter- 

 iorly and slightly so laterally. 



A last inferior tooth (fig. 15), no. 19862, is comparable in size 

 and shape to corresponding teeth of Nothrotherium from Rancho 

 La Brea. It is larger than no. 8338 from Potter Creek Cave, but the 

 latter evidently belonged to a younger individual. The tooth from 

 Hawver Cave is characterized by the well-rounded inner face and the 

 deep median groove of the outer face. The anterior and posterior 

 faces are planes and are joined by the broadly rounded inner side. 

 The faces join the outer side in well-rounded corners. The inner 

 posterior border of the triturating surface is beveled as in Megalonyx 

 jeffersoni. 



Measurements 



No. 19864— 



Width of palate between alveoli of M 3 24 mm. 



Length from anterior end of M- to posterior end of M 1 , alveolar 



measurement 48.5 



M 1 , greatest anteroposterior diameter at triturating surface 12.7 



M 1 , greatest transverse diameter at triturating surface 17 



