16 



occipital presents a pair of vertical foss* separated by a low ridge. Its 

 external crest is not continued to that of the squamosal part of tlie zyg- 

 oma. The meatus auditorius is quite small, as is, also, the mastoid tu- 

 berosity. The paramastoid is large and stout. 



Measurements of cranium. M. 



From occipital condyle to incisor teeth 0.33(K 



From occipital condyle to last upper molar. 140 



From occipital condyle to fundus of palatal notch 165 



Length of entire molar sei ies .124 



Length crown P. m. 1 , Oil 



Length crown P. m. 2 025 



Width crown P. m. 2 018 



Length crown first true molar - 017 



Width crown first true molar .020' 



Height crown first true molar 013 



Length diastema 027 



Height crown of canine 015 



Width of arc of incisors 050 



Length from I. 1 to P. m. 1 069 



Length from I. 1 to nasal-notch (oblique) 080 



Length from I. 1 to orbit 198 



Diameter of orbit 045 



Width nasals at notch 031 



Width front at middle orbit 076 



Width of zygomata posteriorly , 132 



Width between meatus 088 



Width between middle molars 038 



Width of occipital foramen and condyles 054 



Length mandibular ramus 270 



Length from end incisors to last molar 190 



Length from end incisors to first molar 077 



Length from end incisors to canine, (axial) 025- 



Depth s;y mphysis in front of foramen mentale. 028 



Depth ramus at M. 1 '. 043. 



Depth ramus at M. 6 063. 



The sl-eleton is noteworthy for the disproportionately large size of the 

 cervical as compared with the djrsal vertebrsie. The large size of the 

 head, compared with the rest of the animal, was supplemented by 

 the length and slenderness of the limbs, which considerably exceeded 

 the proportions they bear in the existing horse. The lumbar vertebrae 

 are slightly opisthocoelian — the dorsals strongly so. The cervicals are 

 large and moderately elongate. The size results from the great devel- 

 opment of the processes, since the centra do not materially exceed those 

 of the lumbars. The atlas is not much expanded, and has a well-marked 

 tubereulnm atlantis, and very low neural keel. 



The limbs are slender and the hoof small. The humerus is more 

 curved than in the horse, and has a strong tubercular deltoid crest. 

 The proximal tuberosities are very difi'erent from those of the horse. 

 The external is largely developed, "but is not produced into a hook, nor 

 extended into a longitudiaal crest. The inner bicipital tuberosity is a 

 little more prominent and curv^es hook-like outward, inclosing with 

 the outer, a deep notch. It is continued at right angles along the in- 

 ner aspect of the head into a straight crest, their angle of union is 



