10 Prof. Owen on the Remains of a 



dullary cavity along the middle of the shaft, with dense pa- 

 rietes an inch thick. The total length of the fossil is twenty- 

 two inches ; its greatest breadth across the upper or proximal 

 end, where the neck begins to bend inwards, is ten inches. 



Traces of the smooth pitted surface at the broken distal end 

 indicate the place of junction of the articular epiphysis, and 

 prove that the entire shaft of the femur is here preserved ; a 

 part of the epiphysis is anchylosed to the shaft. 



The portion of the molar tooth was obtained from the same 

 locality as the femur, and if it belong, as is most probable, to 

 the same animal, proves it to be most nearly allied to those 

 Pachyderms, as the Dinotherium and Mastodon giganteus, 

 in which the grinding surface of the teeth is raised into broad 

 transverse ridges. Parts of two of the anterior ridges, and a 

 smaller or lower one which runs across the base of the first, 

 at the anterior part of the crown of the tooth, are here pre- 

 served ; but the accuracy of the figures (figs. 2. and 3.), which 

 are of the natural size, precludes the necessity of further de- 

 scription. The apex of both the higher ridges has been worn 

 by mastication, but not to such an extent as is usually seen 

 in the small deciduous molars of the Mastodons : there is less 

 trace of a division of the summit of the ridge into mammillce 

 than would be presented by a similar sized molar, equally 

 worn down, of the Mastodon gigantens, in which the two 

 mammillae would be indicated by a median constriction. The 

 transverse ridges are still more subdivided in the other known 

 species, as M. longirostris, M. latidens, M. angustidens, or M. 

 elephantdides : the Australian tooth more resembles that of the 

 Dinotherium in the simplicity of the transverse eminences, but 

 there is a deposit of cement or crusta petrosa at the bottom 

 of the intervening valleys, which I have not observed in any 

 molar of Dinotherium. As the bones of the extremities of 

 this most remarkable genus, the Dinotherium, have not yet 

 been discovered, the affinities of the Australian Pachyderm 

 to that genus do not at present derive further elucidation from 

 the femur above described. 



The close relationship of the Mastodon to the Dinotherium 

 has received additional proof by the discovery of the two tusks 

 of the lower jaw in the young individuals of the Mastodon, 

 and by the retention of one of these as a sexual distinction of 

 the male, in Mastodon giganteus : and the highly interesting 

 member of the ancient fauna of Australia, revealed by the 

 remains above described, must be referred, on their evidence, 

 to the same natural family of gigantic Pachyderms as that 

 which includes the Mastodons and Dinotheres, and to a spe- 

 cies distinct from any yet determined. The interests of science 



