66 Annals of the Carnegie Museum. 



is of moderately large size. The lachrymal pit is large and deeply 

 excavated. The position of the infraorbital foramen is above P±, 

 which is a distinguishing feature of the genus Merychyus. It is of inter- 

 est to. note the greatly inflated region of the anterior part of the jugal 



and the lachrymal bones. There are deep, narrow, subovate excava- 

 tions on either side of the median line of the basisphenoid. The 

 tympanic bulla was evidently of large size, and the postglenoid is 

 remarkably heavy. The posterior nares are not so far back as in 

 Merycochcerus proprius. 



Measurements. 



No. 1337. No. 1411. No. 1049. 



mm. mm. mm. 



Distance from postglenoid process to M 3 ~ 62 



Transverse diameter of brain case 66 



Greatest transverse diameter of skull 1 60 



Vertical diameter of jugal below orbit 32 



Length of upper molar series 56 59 



Length of upper premolar series 48 



Antero posterior diameter of P- 1 - II 



Transverse diameter of P 1 - 5 



Antero-posterior diameter of P^ 13 



Transverse diameter of P^ 9 



Antero-posterior diameter of P^ 12 



Transverse diameter of P 3 - 12 



Antero-posterior diameter of P^ 12 



Transverse diameter of Pi 14 



Antero-posterior diameter of Ml- 13 16 13 



Transverse diameter of Mi 16 19 



Antero-posterior diameter of M^ 20 23 



Transverse diameter of M 2 - 20 23 



Antero-posterior diameter of M^ 24 26 



Transverse diameter of M^ 21 24 



Length of mandible 206 



Vertical height of mandible at coronoid process 103 



Vertical diameter of mandible at M ¥ 37 46 



Vertical diameter of mandible at P3 26 36 



Length of lower molar-premolar series 103 1 1 8 



Length of lower premolar series 43 51 



Antero-posterior diameter of P T II 13 



Transverse diameter of P T 7 7 



Antero-posterior diameter of P2 10 12 



Transverse diameter of P2 6 6 



Antero-posterior diameter of Pg 14 14 



Transverse diameter of P^ 9 



Antero-posterior diameter of P ¥ 15 16 



