NO. 2147. 



T^YO EXTINCT MAMMALS FROM TEXAS— HAY 



117 



is convex (pi. G), but undulating. Also, while the parietal part 

 of the profile in the Brazilian species is pretty strongly convex, 

 in the Texan species it is undulating and little convex. 



On the other hand, N, texanum is very closely related to N. grcDcili- 

 ceps Stock. The differences which are believed to exist are con- 

 sidered below. 



The following measurements have been made on the skull at hand. 

 In the second column are the corresponding measurements of the 

 skull forming the type of N. grddlheps. The premaxillaj not being 

 present in either skull, the basilar length can be determined only 

 approximately. 



Measurements of skulls in millimeters. 



N. graciliceps. 



Basilar length 



Distance from front of occipital foramen to front of 



maxilla. 



Distance from rear of occipital condyles to front of 



maxilla 



Lateral extent of occipital condyles 



Width of skull at mastoid processes 



Width across ekidl above the orbits 



Length of nasals at the midline 



Width of nasals, combined, at hinder end 



Height of anterior end of snout 



Width of anterior end of snout 



Height of occipito-parietal suture above lower face 



of basioccipital 



Height of occipito-parietal suture above lower face 



of occipital condyles 



313z 



323rh 

 286 



The upper half of the hinder aspect of the skull presents a very 

 rough surface, for the attachment of muscles. A considerable part 

 of the supraoccipital appears on the upper surface of the skull. The 

 suture between the parietals is 70 mm. long. The parieto-squamosal 

 suture is not as distinct as could be desired, but may be followed with 

 considerable certainty. The squamosals have at the front end a 

 width of 46 mm. 



The suture between the frontals has a length of 110 mm. The 

 lower edge of the bone of the right side is broken away; but it is 

 present on the left side, where it is seen to come into contact with 

 the hinder border of the nasal, overlapping its lower hinder angle 

 and the hinder border of the lachrymal. The lower hinder angle of 

 each frontal widely joins the corresponding squamosal. The frontals 

 are coossified with the nasals, but the line of the suture can be easily 

 traced. 



The length of the suture between the nasals is 105 mm. These 

 bones are so intimately consolidated with the maxillse that it has 



