318 



concavity which extends forwards to the parallel of the interspace between 

 the last and penultimate molars ; the regularity of the convex line ex- 

 tending from the posterior part of the ascending ramus to the lower 

 border of the jaw is interrupted by a slightly produced obtuse prominence 

 at the middle of the inflected angle. The post-molar part of the alveolar 

 process forms a broad platform on the inner side of the base of the coro- 

 noid, and is defined by a well-marked angle at its inner and posterior 

 part, in which it resembles both the lower jaw of the proboscidian Pa- 

 chyderms and that of the Wombat. The entry of the dental canal is 

 situated as in the Diprotodoji australis and the Nototherium inerme. 

 The coronoid process has the same extensive antero-posterior origin, 

 and the same thinness as in No. 1505, but it is rather more concave 

 externally. 



From the alluvial or newer tertiary deposits in the bed of the Conda- 

 mine River, west of Moreton Bay, Australia. 



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



1507. A segment of the right ramus of the lower jaw of the Nototherium inerme, 

 including the sockets of the penultimate and last molars, with the pos- 

 terior fang of the one and the anterior fang of the other. The empty 

 portions of the sockets show the longitudinal ridge of bone which fits 

 into the groove on that surface of the fang which is towards the centre 

 of the socket. The origin of the coronoid process opposite the anterior 

 part of the last molar is a repetition of the character by which the entire 

 jaw No. 1505 differs from the specimen No. 1506, and the length of the 

 posterior part of the socket of the last molar establishes the full maturity 

 of the present as of the entire jaw No. 1505. The concavity along the 

 lower part of the inner surface of the ramus, formed by the bending in of 

 its lower margin continued from the angle of the jaw, is well indicated in 

 the present fragment, which likewise shows the course of the dental 

 canal along the outer part of the bottom of the alveoli. 



This fragment of jaw demonstrates a coarser cancellous structure than 

 in the Rhinoceros, or even than in the Elephant. 



