GEOLOGICAL SOCIETY OF PENNSYLVANIA. 



353 



tions of this fragment, is observed a portion of bone, 

 which most probably formed part of the intermaxillary 

 bone. Letter d points to a vacancy occurring between 

 the second and third teeth. 



At pi. 24, fig. 3, there is an anterior view of this 

 portion of jaw. 



Dimensions of the various portions constituting this 

 fragment :— 



Total length of tlie fragment of upper jaw, 



15 inches 



Greatest width posteriorly, from the base to 







the alveoles, ..... 



5 





Which gradually tapers anteriorly to 



2 





Thickness of the side of the maxilla, 



2.5 



li 



Thickness of the palate bone, 



0.7 



a 



Height of the largest double tooth, 



2.6 



11 



Greatest width of do. 



3 



li 



Height of the root projecting above the socket, 



1 



li 



Single teeth, height, .... 



3 



it 



Breadth of do., ..... 



1 



it 



Length of the socket which contained the 







canine, ...... 



2.3 



it 



Breadth of do.. 



1.3 



li 



Height of conical double tooth. 



2.3 



a 



Breadth of do., ..... 



2.7 



11 



Depth of root descending into socket, 



2.5 



11 



Inferior maxilla. PL 23, Jig. 1 . 



General aspect of the lower jiuv, compressed or sub- 

 cylindricaij the shaft being hollow, and the cavity in the 

 fossil filled vvith the matrix or limestone; the solid por- 

 tions of the bone varying from a fourth to half an inch in 

 thickness, with the exception of the alveolar portion, 

 which is thicker. External or dermal aspect of the jaw 

 slightly convexj in the direction of its axis, scabrous and 

 weatherworn. The inner or mesial aspect displays the 

 smooth and natural appearance of the bone, excepting a 

 portion of the posterior extremity, which is scabrous and 



