AND VARIOUS OTHER BONES OF THE MASTODON. 



41 



sively on the tubercle at the root of the zygomatic process. This surface re^ 

 sembles, in shape, that on the trapezium of the human hand for the thumb, 

 except that it is proportionately more oblong, as it measures five inches by two 

 and a half; its margin is sharp, elevated, and well defined. There is behind 

 the tubercle a depression corresponding with the glenoid cavity of the Elephant, 

 but it is narrow, deep, and rough ; it appears not to have had a coating of carti- 

 lage, and, from its constricted condition, could not have entered into the con- 

 tour of the temporo-maxillary joint. 



The upper maxilla has a tooth on each side which measures seven and a 

 fourth by four and a half inches. These teeth converge behind and were 

 placed four inches in advance of the pterygoid process : they are furnished 

 with five denticules, which are much worn. 



The left alveolus for tusk in the incisive bone is very complete, the right 

 one is slightly mutilated at the margin. Their depth is nineteen inches — 

 transverse diameter, four and three-fourths of an inch— and vertical diameter 

 five and a half inches. 



The following supplementary measurements may be of some value : 



From end of alveoli of tusks to occipital condyles three feet two inches. 



From inferior margin of foramen magnum to vertex one foot five inches. 

 Transverse diameter of occiput two feet two inches. 



From vertex to spine of bone, between anterior nares, one foot nine inches. 



From orbit to orbit one foot nine inches. 



Incisive fossa four inches deep. 



From posterior margin of pterygoid process of sphenoid bone, to anterior edge 

 of alveoli for tusks, two feet four inches. 



From anterior edge of foramen magnum to posterior nares five inches. 



Depth of temporal fossa, from bottom to the crown of the zygomatic arch, 

 nine inches. 



From superior margin of temporal fossa, to inferior margin of pterygoid pro- 

 cess, one foot ten inches. 



Diameter of orbit six and a half inches. 



Across alveoli for tusks, and immediately below infra orbitary foramen, six- 

 teen inches. 



Across alveoli for tusks, at their inferior end, eighteen inches and a half 

 viii. — L 



