Cope.] &>^ [Jan. IS, 



opposite the internal extremity of the glenoid face, instead of the external 

 as in M. superbus, or the middle, as in M. macrostegus. The border 

 descending to the supraauricular crest is thin and vertical in direction, 

 and the superior angle stands above the middle of the postglenoid process, 

 not external to it, as in the two species above named. The postglenoid 

 process is robust and has a convex posterior face. The paroccipital pro- 

 cess is long and acuminate. An external truncate ridge on the front of its 

 base partially embraces the meatus auditorius, and curving forwards be- 

 comes the anterior edge of the process, which is separated from the post- 

 glenoid by but a narrow interval. The tympanic bone forms a tube more 

 distinct from the surrounding regions than in the other species here de- 

 scribed, and has a longitudinal inferior keel, which is not visible in the M. 

 superbus and M. macrostegus. It is separated at the meatus by but a 

 short interval from the base of the postglenoid process. The supraauricu- 

 lar and mastoid crests unite and form a short acute crest, which does not 

 continue into a prominent posttemporal, but descends into a mere angle, 

 which continues as a fine line to jthe convexity of the true posttemporal 

 crest above. The latter arises from the bifurcation of the sagittal crest, 

 and after a strong convexity descends with its fellow to a narrow promi- 

 nent convex ridge, which rises from the foramen magnum, Thus the oc- 

 ciput on either side of this prominent middle line is deeply excavated, and 

 the fossa is bounded on each side and anteriorly by the low posttemporal 

 angle, and the more prominent mastoid ridge. There is no median keel. 

 The median ridge of the occiput is more prominent and not so flat as in 

 M. superbus, but is more as in M. macrostegus. The sagittal crest is well 

 developed, and has a straight superior border, which is not thickened as 

 in M. chelydra. The anterior temporal ridges are represented by an angle 

 which is nearly right. The superior squamosal suture is marked by a 

 prominent ridge. The front is gently convex transversely, and the supra- 

 orbital border is more strongly decurved than in M. superbus, which are 

 more so than in M. macrostegus. 



The basicranial axis makes a strong angle with the basifacial as in the 

 other species of the genus, showing that the face was presented obliquely 

 forwards, as in the peccary. The section of the basioccipital bone be- 

 tween the paroccipital processes is V-shaped, owing to the presence of a 

 strong median angle. In M. macrostegus this bone is similar, but in M. 

 superbus it is much flatter, and there is a weak median keel. The sphenoid 

 is in line with the occipital and has a broadly rounded-truncate inferior 

 face. The otic bullae are large and compressed. They extend from the 

 middle of the base of the paroccipital process to considerably in advance 

 of the postglenoid process, and approach very near to the glenoid surface. 

 The interval which separates them is small, equaling one-fifth the antero- 

 posterior diameter of the bulla. This is very different from the M. 

 macrostegus, where the space between the glenoid surface and the bulla, 

 is equal to the anteroposterior diameter of the latter near the middle. As 

 already pointed out, this species agrees with the species just named in the 



