319 



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. 



1508. A fragment of the anterior part of the right ramus of the lower jaw of a 

 mammalian quadruped as large as the preceding, and with molar teeth 

 of the same size, apparently a Nototherium. It shows the sockets of the 

 three anterior molar teeth, with the base of the fourth and the hinder 

 fang of the third implanted in the jaw. The lower fractured surface ex- 

 poses the dental canal extending obliquely from without inwards below 

 the sockets of the anterior molars, and then bifurcating ; the outer 

 and larger division terminating at the mental foramen, and an inner and 

 smaller one extending forwards nearer the symphysis, but without any 

 trace of the socket of a large incisor. The first molar tooth is situated 

 anterior to the commencement of the symphysial union, as in No. 1505, 

 but there is no indication of the base of the coronoid process ex- 

 terior to the fourth molar as in that specimen. The gradual expan- 

 sion of the jaw below that tooth is more like that in the Nototherium 

 Mitchelli, to which species the present fragment may with most proba- 

 bility be referred. 



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. 



1509. The astragalus of a large marsupial quadruped, probably the Nototherium 



inerme. The peculiarities of this astragalus will be obvious to the compara- 

 tive anatomist from the following description. It is a broad, subdepressed 

 and subtriangular bone, the angles being rounded off, especially the an- 

 terior one ; the upper or tibial surface is quadrate, concave from side to 

 side, in a less, degree convex from before backward : a ridge extend- 

 ing in this direction divides the tibial from the fibular surface, which 

 slopes outwards at a very open angle, and maintains a nearly horizontal 

 aspect, presenting an oblong trochlea for the support of the fibula, 

 shallower, and one-third smaller than that for the tibia. The tibial arti- 

 cular surface is not continued upon the inner side of the astragalus, but 



