64 Annals of the Carnegie Museum. 



tebrate Fossils), which I regard as of the same variety as the cranium 

 No. 1399, has the mandible shallower and the lower premolars less 

 crowded than in the type of Merycochcerus proprius. 



From other remains in the Carnegie Museum which are like those 

 in the American Museum which have been referred to M. proprius by 

 Dr. Matthew (Memoirs Am. Mus. Nat. Hist., Vol. I., pp. 397-418, 

 1 901) the specimens here described differ by having a longer sagittal 

 crest, a less prominent ridge on the parietals, and a less developed 

 process on the posterior part of the zygomatic arch. The brain cavity 

 also is apparently larger. 



Measurements. 



No. 1399. No. 1306. 



mm. mm. 



Greatest length of the skull 322 



Distance from occipital condyle to incisors 314 



Distance from postglenoid process to M- 3 - 79 79 



Distance from Mi to and including incisors 191 189 



Transverse diameter of occipital condyle 56 



Greatest transverse diameter of skull, approximately 215 



Greatest transverse diameter of brain case no 



Transverse diameter of frontal s over the orbits 125 



Antero-posterior diameter of orbit 41 



Vertical diameter of orbit 41 



Antero-posterior diameter of the canine 12 12 



Transverse diameter of the canine 13 12 



Antero-posterior diameter of Pi 15 



Transverse diameter of Pi 8 



Antero-posterior diameter of Pi 16 17 



Transverse diameter of Pi II 11 



Antero-posterior diameter of P^ 16 16 



Transverse diameter of Pi 12 12 



Antero posterior diameter of PA 15 15 



Transverse diameter of PA 17 17 



Antero-posterior diameter of Mi 23 23 



Transverse diameter of Mi 23 23 



Antero-posterior diameter of M-? 34 33 



Transverse diameter of Mi 26 26 



Antero-posterior diameter of Mi 37 37 



Transverse diameter of Mi at median external rib of the tooth.. 26 26 



Greatest length of mandible 265 



Greatest vertical depth of mandible 134 



Vertical depth of mandible at Mj 54 



Vertical depth of mandible at P ¥ 45 



Length of lower dentition 185 



Length of premolar series 67 



