510 University of California Publications in Geology [Vol.10 



distal face of the astragalus. With a position internal, as in Hapalops, 

 the facet for the sustentaculum borders the oblique interarticular 

 channel just mentioned. It is continuous with the cuboid facet which 

 in major part is situated on the palmar surface of the head. The 

 neck is apparently much less conspicuous than in the Brazilian form. 

 It is not constricted on the inner side as in the latter. The distal 

 surface of the head is more deeply excavated for the navicular than 

 in Hapalops. 



Measurements of Astragalus, no. 19856 



Greatest anteroposterior diameter 101.6 mm. 



Greatest transverse diameter across tibio-fibular surface, measured 



at a right angle to antero-posterior diameter 107.4 



Depth of fibular surface at distal end 66 



Transverse diameter of head across navicular depression 54.7 



Greatest anteroposterior thickness of head 44 



a 



Fig. 29. Nothrotherium shastense hawveri, n. subsp. Articular end of cal 

 caneum, no. 19871, X Vj. a and a', facets for astragalus; c, facet for cuboid. 

 Pleistocene of Hawver Cave, near Auburn, California. 



The calcaneum is represented by a fragment (fig. 29) showing the 

 greater portion of the articulating end. In this specimen, no. 19871, 

 the sustentaculum bearing the small facet for the astragalus is well 

 preserved as is also the articulating surface for the cuboid, but the 

 large external facet for the astragalus has been partly broken away. 



The articulating end thus preserved, resembles that in the cal- 

 caneum of the Brazilian species of Nothrotherium illustrated by Bern- 

 hardt. 22 No. 19871 differs from the latter in having the sustentacular 

 facet and the facet for the cuboid separated by a very narrow inter- 

 space and there is no indication of a bridge of bone connecting the two 

 and lying adjacent to the median channel. The cuboid facet and the 



22 Bernhardt, J., op. ext., pi. 5, figs. 3 and 4, 1878. 



