470 Annals of the Carnegie Museum. 



of No. 562 differ from those of O. /oiigipes. The spines are heavier 

 and higher than in that genus. On the axis the spine slopes forward 

 at a greater angle and extends farther backward than does that in O. 

 loiigipes. The length of the axis and the third cervical is more nearly 

 equal than in O. longipes and the inferior keels are stronger. The 

 fifth cervical vertebra of the type, No. 664, has a distincly higher and 

 heavier spine (PL XII, Fig. 4), than the corresponding vertebra of 

 O. longipes, otherwise it is similar to that of the latter species though 

 somewhat smaller. 



Measurements of Skull and Vertebra. 



Length of cranium from incisor 3 to external auditory meatus 268 mm. 



Total length of dental series from incisor 3 to and including molar 3 165 mm. 



Distance from incisor 3 to pm. 2 64 mm. 



Length of continuous molar-premolar series 93 mm. 



Total length of premolars 2 to 4 37 mm. 



Total length of molar series 56 mm. 



Greatest length of nasals no mm. 



Greatest length of mandible 255 mm. 



Greatest height including coronoid process 138 mm. 



Height of coronoid 44 mm. 



Depth of ramus back of molar 3 45 mm. 



Depth of ramus at diastema in front of pra. 2 22 mm. 



Distance from canine to pm. 2 45 mm. 



Length of continuous molar premolar series 100 mm. 



Length of premolars 2 to 4 36mm. 



Length of molar series 65 mm. 



Greatest length of atlas approximately 75 mm. 



Greatest width of atlas approximately 75 mm. 



Greatest width of cotylus 55 mm. 



Greatest length of cervical 3 1 30 mm. 



Length of centrum of cervical 3 118 mm. 



Greatest length of cervical 4 126 mm. 



Length of centrum of cervical 4 112 mm. 



Greatest length of cervical 5 124 mm. 



Length of centrum of cervical 5 approximately 1 00 mm. 



Greatest length of cervical 6 , 106 mm. 



Length of centrum of cervical 6 86 mm. 



The Fore Limb and Foot. — (PI. XIII.) The limbs of O. brachy- 

 odoiitus (No. 664) are elongated and rather lighter in comparison with 

 the cranium, than in O. longipes. The internal epicondyle of the 

 humerus is of greater development and the curvature of the ulno- 

 radial shaft is more pronounced in O. bracliyodontus than in O. longi- 



