BY C. W. DE VIS. 161 



The mandible has been bequeathed by an individual well stricken 

 in years. 



The symphysis is 194 mm. in length; its upper surface descends 

 caudad at an angle of 20°, in strong contrast with its precipitous 

 descent in E. (/rata. Beneath the posterior end of the symphysis, 

 on either side of its central line, is a deep excavation, confluent 

 with its fellow posteriorly but separated from it anteriorly by a 

 broad backwardly projecting spine, which gives a reniform shape 

 to the excavation as a whole. The posterior half of the diastema 

 is compressed ; its edge ascends from the premolar forwards and 

 about the middle of the diastema parts from that of the anterior 

 half and curves downwards and forwards upon the outer surface 

 of the incisive socket, but no tubercle is developed upon it as in 

 E. grata. The anterior half of the diastema becomes less and less 

 compressed as it approaches the incisive outlet. The dentary limb 

 posteriorly is low, thick, and convex ; at m 4 it has a height of 

 90 mm., with a thickness of 67 mm. Beneath the anterior grinders 

 its outer surface becomes concave to a notable degree, but resumes 

 its convexity in front of the anterior dental foramen, which is large 

 and placed, as to its posterior margin, in the vertical of the anterior 

 fang of the premolar. The articulating limb presents only the 

 lower part of the masseteric fossa; this is, for a Nototheroid, 

 rather deep, and has its surface corrugated by ridges and furrows 

 which have a roughly concentric course near the base of the fossa, 

 above it an irregular converging course towards the base. On the 

 inner side the post-molar ledge behind the last molar rises into 

 a strong abutment against the base of the tooth ; this tapers off 

 and subsides before reaching the angle of the ledge. The angle is 

 well marked, and from it a broad low ridge runs upwards and 

 backwards to the posterior dental foramen, which is large and is 

 placed further from the angle of the ledge than this is from the 

 last molar. The channel between the raised margin of the ledge 

 and the coronoid process is contracted; the hinder surface of w 4 is 

 level with the basal edge of the coronoid process. The inferior- 

 contour of the mandible would be a regular parabolic curve but 

 for a slight emargination beneath the anterior dental foramen. 



