172 



THE MERYCQIDODONTID/E 



Specific Characters: The skull (mesocephalic) is rather broad, low, and massive in propor- 

 tion to its length. The muzzle is inflated. The zygomatic arches are slender and the posterior 

 angles low, the whole arch rising but little posteriorly and being nearly parallel with the tooth row. 

 The maximum expansion is just in advance of the glenoid surface. The malar is weak below the 

 orbits. There are no facial vacuities. The nasals are rather shortened in proportion to the short 

 face, are gently convex transversely, and are pointed posteriorly, with the widest point just back of 

 the narial opening. The lacrimal lies in advance of the orbit in part, and the lacrimal fossae are deep 

 and large. The frontals are moderately flat and wide and extend in advance of the lacrimal. The 



Fie. 124. — Merycoides cursor Douglass. Skull and jaw. GHT. Cat. No. 1222 CM. 3/4 nat. size. 



(After Douglass, 1907.) 



orbits are large and nearly circular and look chiefly outward. The temporal ridges are low and 

 unite over the glenoid surface to form a rather short and low sagittal crest. The supraoccipital crest 

 overhangs the occipital condyles considerably, and the wings are fairly close together. The brain 

 case is low and laterally inflated. The external auditory meatus is situated on a line but slightly 

 above and posterior to the glenoid surface. Its direction is outward and backward rather than 

 upward. The palate is narrow and convex, with the V-shaped palatonarial border well back of the 

 last molars. The basicranial axis is fairly steep. The glenoid surface is rather short transversely 

 and somewhat convex anteroposteriorly. The postglenoid processes are small and short, being less 

 than half the length of the glenoid surface. The paroccipital processes are triangular in outline, 

 short and moderately heavy, and located directly behind the bulls, which are comparatively large. 

 Index: 0.55. 



Mandible: The symphysis is normal for the rather slender jaws. The chin slopes downward 

 and backward at an angle of about 40° from the line of the premolars. The inferior angle of the 

 chin is well marked. The lower border of the ramus is nearly straight to the end of M 3 and then 



