A Remarkable Ground Sloth 7 



terior third of the parietals, a feature which also varies in Stock's material until it is 

 hardly discernible in some. 



The zygomatic process of the squamosal of the Yale skull is long and slender, as 

 in N. shastense, but is slenderer at the anterior end with more of a gap between it and 

 the malar. This again may be a juvenile character. The malar also differs in minor 

 details, the dorsal process being longer and slenderer, while of the ventral prong the 

 reverse is true. In most of the Rancho la Brea specimens the antero-external angle of 

 the parietal meets the alisphenoid. Occasionally, however, it does not, nor does it in 

 the Yale skull. 



Fi g- 3 



Fig. 4 



Fig- 5 



Premaxillaries. — The premaxillaries (Figs. 3, 4, 5, Plate III), although origi- 

 nally present in the Rancho la Brea specimens, unfortunately have not been found in 

 the collections. In our skull they are present but are obscured by the soft parts below 

 and somewhat from above. Posteriorly they have a broad bearing upon the maxillaries, 



