1884.] 



525 



[Cope, 



crania of the M. superbus, where both are well preserved and exposed, the 

 bulla is considerably more prominent than the postglenoid process. The 

 glenoid surface is well-defined and equally wide at both extremities, The 

 inferiorly presented surface of the zygomatic arch, is wider than in any of 

 the other species, including examples of M. superbus of superior dimensions 

 in other respects. The surface is rugose. The length from a line connect- 

 ing the median external columns of the last superior molar, to the poste- 

 rior nareal border, enters three times into the distance from the latter to 

 the border of the foramen magnum. In M. superbus it goes three to three 

 and a half times ; in M. macrostegus and M. montanus once only. Be- 

 hind the molars the produced palatal roof is more concave than between 

 the last two true molars. The palate becomes then more Concave (convex), 

 and between the first premolars and canines becomes flat, and expands 

 laterally. The nareal fissure is not much contracted between the pre- 

 maxilliaries. 



The infraorbital foramen is above the anterior half of the superior fourth 

 premolar, and is of moderate size. The frontal foramina are separated by 

 a space which is less than half as wide as that which separates each one 

 from the superciliary border. There is no supraorbital notch. The in- 

 cisive foramina are large, are wider than long, and approach close to the 

 bases of the canine teeth. The palatine foramina are minute or obsolete. 

 The foramen ovale is isolated and is opposite the junction of the glenoid 

 and postglenoid surfaces. The jugular foramen is isolated by the exten- 

 sive contact of the otic bulla and the basicranial axis. Perhaps the 

 condyloid foramen is included in it, as I do not find it in the usual position. 

 The animal is so old that no sutures are visible. 



The teeth are not all cleared from the matrix, which is hard and brittle. 

 The first true molar is much worn. The first premolar is two-rooted, and 

 is separated from the canine by a diastema equal in length to the long dia- 

 meter of its crown. 



Measurements. M. 



Length from occipital condyle to front of canine tooth. .300 



" " " '.' " postglenoid process. . . .041 



" " " " " postfrontal process. .. .132 



" " " " " palatonareal border . . .118 



«•■ " " " " end of last molar 146 



-r.. r. ... f vertical 0455 



Diameters of orbit < .„ 



I transverse 039 



Depth of malar bone at middle of orbit. 034 



" " zygomatic process to glenoid face behind 088 



Width of top of muzzle at preorbital fossa 043 



" at middle of supraorbital border 094 



" " malar below orbit 160 



" " middle of zygomatic arch 254 



" of occiput at superior crests 050 



