Peterson : Miocene Beds of Nebraska and Wyoming. 43 



terior crescents of M^ are but little worn, indicating a rather young, 

 though fully adult, individual. 



The principal characteristics of the mandible are seen in the shallow 

 temporal fossa, the delicate and backwardly projecting coronoid pro- 

 cess, and the rapidly decreasing depth of the horizontal ramus of the 

 jaw from the angle to the symphysis. The incisors are quite large ; 

 they are closely crowded, and their crowns are spatulate. The in- 

 cisors, canine, and P T form a continuous closed series. The canine 

 is incisiform and Py has a single root and a high trenchant crown. 

 P^ is isolated from P T and P ¥ by diastemata ; the tooth is small and 

 two-rooted. P-g- is also a small two-rooted tooth which is unworn in 

 the type specimen. P ¥ is compressed laterally, but has a normal an-- 

 tero-posterior diameter. The molars increase rapidly in length from 

 before backward ; they are much compressed transversely. The limbs 

 are long and slender and the metatarsals are coossified half their 

 length from the proximal end. The navicular and cuboid are separate 

 as in the camels. The metacarpals are coossified in a less degree than 

 the metatarsals and are nearly as long as the latter. 



Measurements. 



mm. 



Distance from Pi to and including the occipital condyle 15 2 



Distance from Mi to and including the occipital condyle 76 



Vertical diameter of the occipital condyle 20 



Transverse diameter of the occipital condyle 32 



Transverse diameter of the frontals at postorbital process, approxi- 

 mately 95 



Antero-posterior diameter of Pi 6 



Transverse diameter of Pi 3 



Antero-posterior diameter of Pi 10 



Transverse diameter of P* posteriorly 7 



Antero-posterior diameter of Mi 15 



Transverse diameter of Mi 10 



Antero-posterior diameter of Mi 25 



Transverse diameter of M- 2 - 10 



Antero-posterior diameter of Mi 26 



Transverse diameter of Mi 8 



Greatest length of the mandible 184 



Depth of jaw at coronoid process 97 



Depth of jaw at posterior part of M- 3 - 47 



Depth of jaw at diastema in front of Pi 18 



Length of inferior dentition 137 



Antero-posterior diameter of P 1 5 



