Osborn and Speir—Lower Jaw of Loxolophodon. 305 
downward processes below the canine-molar diastema are not 
Pp 
strongly marked. The molar series are nearly parallel. 
the robust process of the lower jaw of U. Leidianum in the E. 
. Museum, they show a disparity in size, that seems unac- 
Countable in genera so closely allied. . 
The dental foramen is large and is situated on a line with 
the molar series. The mental foramen is double and placed 
toed beneath the canine. 
J The processes, as seen from below, have a more outward 
than downward direction, forming at the posterior half of the 
symphysis a broad, slightly concave floor, about six inches in 
Width ; below the lateral incisor they disappear, and the chin 
Narrows into a prow-shaped keel. The inner margin of the 
canine-incisor alveolus is well raised, giving the series the ap- 
Pearance of being placed on the side of the jaw. The alveolus 
's highest at the canine, and dips downward in front; this 
Would throw the teeth greatly out of the horizontal line, were 
it not that the dental series increase rapidly in size forward. 
-He teeth are arranged not in a semicircle, but in converging 
lines two and a half inches apart at the canine and in contact 
at the median incisor; thus the chin is contracted towards its 
extremity above as well as below. Between the dental series 
'n front and the high thin borders of the diastema behind is 
the deeply concave floor of the mouth. 
