114 M, R. Thorpe — New Forms of Agriochoerus. 

 Measurements of Holotype. 



mm. 



Skull, length, occip. condyles to incisors, inc 197* 



Bizygomatic diameter 103* 



Brain-case, max. width 61 



Superior dental series, with C, length 106 



Superior molar series, length 43 



Inferior molar series, length (No. 12665, Y. P. M.) 47.2 



Inferior premolar series, length (No. 12665, Y. P. M.) . . . . 38.7 



* Approximate. 



Agriochoerus migrans (Marsh) 1894. 



Holotype, Cat. No. 10102, Y. P. M. Upper Oligocene (Protoeeras beds), 

 South Dakota. 



Specific characters. — Skull somewhat longer than A. 

 latifrons; deep frontal fossae immediately anterior to the 

 junction of the temporal ridges ; the latter are very short 

 and originate about midway between their junction and 

 the postorbital processes ; palate gently concave ; three 

 superior premolars ; muzzle moderately short ; infra- 

 orbital foramen over posterior part of P^ ; marked con- 

 cavity above and below canine convexity ; anterior zygoma 

 massive, with a prominent ridge, trending outward and 

 downward above M^ ; orbits look upward- and outward ; 

 forehead flat ; nasal bones flat and extend to a line above 

 the anterior margin of the canines; prominent sagittal 

 crest ; palatonarial border pointed, the apex being oppo- 

 site the middle of M^"^ ; pterygoid processes robust ; prom- 

 inent convexity near nasion on a line between the anterior 

 margins of the orbits. 



The above description is much more detailed than the 

 original one by Marsh in 1894, and is the only amplifica- 

 tion of this well marked species since that date. 



Measurements of Holotype. 



mm. 



Skull, estimated length, occip. condyles to incisors, inc 235 



Bizygomatic diameter 128 



Superior dental series, with C, length 110 



Superior dental series, without C, length 70.8 



Superior molar series, length 45 



Diastema between C and P^, length 31 



