270 Prof. Owen on a Molar Tooth of the Mastodon australis. 



Valley. The native stated that the fossil was taken out of a cave 

 further in the interior than those of Wellington Valley, and which 

 Count Strzlecki was deterred from exploring by the hostility of 

 the tribe then in possession of the district. With this circum- 

 stantial account, communicated to me by Count Strzlecki when 

 he obligingly placed the fossil in my hands, and with the pre 

 vious indication of a large Mastodontoid quadruped in the femur 

 transmitted by Sir T. Mitchell from Darling Downs, there seems 

 no ground for scepticism as to the veritable Australian origin of 

 the molar tooth in question, notwithstanding its close similarity 

 with the Mastodon angustidens of the European tertiary strata. 

 It is partially mineralized and coated by the reddish ferruginous 

 earth characteristic of the Australian fossils discovered in the 

 Wellington ossiferous caves by Sir T. Mitchell. 



The amount of difference between the Australian molar and 

 those of the European Mastodon angustidens, though small, equals 

 that by which the molars of the Mastodon Andium are distin- 

 guished from the molars of the Mastodon angustidens; and if 

 species so "nearly allied have left their remains in countries so 

 remote as France and Peru, still more if the Mastodon angustidens 

 or longirostris formerly existed, as has been affirmed, in North 

 America, we need feel the less surprise at the discovery of a nearly 

 allied species in the continent of Australia. 



The fossil in question is the crown of an incompletely formed 

 molar, with the summits of its mastoid or udder-shaped emi- 

 nences entire, its fangs undeveloped, and its base widely exca- 

 vated by the unclosed pulp-cavity. It supports six principal 

 mastoid eminences in three transverse pairs, with a narrow ridge 

 at the anterior part of the base of the crown, and a small qua- 

 drituberculate talon or basal prominence posteriorly : the three 

 transverse eminences are joined together by a pair of small tu- 

 bercles at the basal half of each interspace, placed in the long 

 axis of the crown, and rather to the* outer side of the middle line 

 of the grinding surface, fig. 2. 



The length or antero-posterior diameter of the crown is four 

 inches ten lines : the breadth of the posterior pair of tubercles is 

 two inches eleven lines : the height of the middle eminences from 

 the base of the crown is two inches six lines : the tooth is appa- 

 rently the fourth molar of the left side of the lower jaw. In com- 

 parison with a corresponding molar in the same state of growth 

 of the Mastodon longirostris* of Kaup, a cast of which is now 

 before me, the Australian molar differs in having the principal 

 transverse eminences more compressed antero-posteriorly in pro- 



* If this species be distinct from the Mast, angustidens of Cuvier, the 

 molar teeth seem to me to offer precisely the same characters. 



