346 University of California Publications in Geology [Vol.7 



Behind the weak lambdoidal crest the rugose supraoccipital 

 slopes back at an angle of about 40° from the plane of the 

 parietals. In Nothrotherium the supraoccipital is more promi- 

 nent in superior view than in Megalonyx. 



4 5 



Fig. 3. Nothrotherium graciliceps, n. sp. Skull, lateral view, X %. 

 Rancho La Brea Beds. 



Fig. 4. Nothrotherium graciliceps, n. sp. Skull, posterior view, X %. 

 Rancho La Brea Beds. 



Fig. 5. Nothrotherium graciliceps, n.sp. Skull, anterior view, X %. 

 Eaneho La Brea Beds. 



The thickening of the maxillaries inferiorly (fig. 5) and the 

 pointed anterior margin of their palatal portions (fig. 2) seem 

 to indicate the original presence of premaxillaries. The lateral 

 wall of the maxillary is convex above, becoming slightly concave 



