254 



Order RUMINANTIA. 



Genus Camelopardalis. 



1119. A cast of the lower jaw of the fossil Giraffe of Issoudun {Camelopardalis 

 Biturigum, Duvernoy). 



The original was discovered in a yellowish argillaceous stratum in the 

 digging of a well in the town of Issoudun, and has been described and 

 figured by Prof. Duvernoy in the ' Annales des Sciences Naturelles,' 

 3rd Series, totn. i. Having compared this cast, at the request of Prof. 

 Duvernoy, with the specimens of Giraffe in the Hunterian Museum, it 

 was found that the fossil jaw from Issoudun differed from that in the 

 existing Giraffe, of both the Cape and Nubia, in the greater degree and 

 regularity of the convexity of the lower margin of the ramus below the 

 molar teeth, which was due principally to the smaller height of the 

 ramus below the last molar as compared with its height below the second 

 and third molars. The last molar is relatively smaller in the Issoudun 

 fossil than in the Giraffe ; the posterior lobe is also relatively smaller and 

 more simple. The penultimate and the antepenultimate teeth are more 

 equal in size in the Issoudun fossil. In proportion to the extent of the 

 molar series, the fossil has a relatively shorter jaw and a shorter symphysis. 

 The symphysial expansion for the incisive teeth commences in the fossil 

 immediately anterior to the outlet of the dental canal, but it commences 

 an inch in advance of the outlet in the existing Giraffe. The length of 

 the ramus between the first molar and the posterior commencement of the 

 symphysis is greater in the fossil than in the existing Giraffe. The outer 

 surface of this part of the ramus, between the molar and the symphysis, 

 is more convex in the fossil. The concavity continued from behind the 

 last molar upon the anterior ascending border of the coronoid process is 

 absolutely wider and deeper in the fossil. The height of the ascending 

 ramus from the angle to the condyloid process, as compared with the 

 length of the molar series, is less in the fossil. 



In all the foregoing points, except the relative length of the symphysis, 



