316 



coronoid process exterior to the hinder molar, in the thickness of the 

 horizontal ramus as compared with its length and the convexity of its 

 outer surface ; and it also resembles the Proboscidians, in common with 

 the Kangaroo, in the small number of the grinding teeth. 



From the lower jaw of the Kangaroo and Wombat that of the Noto- 

 therium differs in the absence of the deep excavation on the outer side of 

 the ascending ramus, which, in those Marsupials, leads to a perforation in 

 the base of that part of the jaw, and it also differs in the inferior depth of 

 the inner concavity and the inferior extent of the inward production of 

 the angle of the jaw ; besides the more important difference in the 

 absence of the large incisor tooth. From the jaw of the Diprotodon, 

 No. 1 460, the present fossil differs in the much smaller vertical extent 

 of the symphysis, and in the convexity of the jaw at its outer and an- 

 terior part, and more particularly in the absence of the incisive tusk 

 and its socket ; but it must have closely resembled the Diprotodon in 

 the general form and proportions of the molar teeth. 



From the alluvial or newer tertiary deposits in the bed of the Condamine 

 River, west of Moreton Bay, Australia. 



Presented by Lieut.- Col. Sir T. L. Mitchell, C.B. 



1506. The posterior half of the left ramus of the lower jaw of the Nototheriuni 

 Mitchelli, wanting the condyloid and the upper part of the coronoid 

 processes, and containing the last two molar teeth, the crowns of which 

 are much fractured, but demonstrating that they were divided into two 

 principal transverse ridges. The antero-posterior extent of both teeth 

 together is three inches three lines, the last molar being two lines longer in 

 this dimension than the penultimate one : its transverse breadth is one inch 

 two lines. The dentine of the crown is encased in a sheath of enamel of 

 nearly one line in thickness, with a smooth and polished surface, impressed 

 at the outer part and near the base of the tooth, where the enamel is 

 principally preserved, with fine parallel and nearly horizontal transverse 

 lines 



Part of the abraded surface of both transverse ridges is preserved in 

 the penultimate grinder, showing that hey had been more than half 



