268 Prof. Owen^s Description of a Fossil Molar Tooth 



Ctenodus, that in a letter lately received, Mr, Harvey tells me that 

 at an advanced stage of growth, the receptacles of the individuals 

 with tetrasporic fruit present a pore corresponding with each cell, 

 by which the spores escape. 



XXXIY. — Description of a Fossil Molar Tooth of a jNIastodon 

 discovered by Count Strzlecki in Australia. By Prof. Owen, 

 F.R.S. 



The large fossil femvu', transmitted to England in 1842 by Lieut.- 

 Col. Sir T. L. ^Mitchell, Surveyor-General of Australia, from the 

 alluvial or tertiary deposits of Darling Downs, and described in 

 the 'Annals of Natural History^ for January 1843, p. 8. fig. 1, 

 gave the first indication of the former existence of a large Mas- 

 todontoid quadruped in Australia. 



The portion of tooth described and figm-ed in the same com- 

 munication (p. 9. figs. 2 and 3), presenting characters very like 

 those of the molars of both the Mastodon giganteus as well as of 

 the Dinotherium, and being from the same stratum and locality 

 as the femm- with which it was transmitted, was regarded by me 

 as having most probably belonged to the same animal ; and, on 

 the authority of drawings subsequently received from Sir T. j\Iit- 

 chell, was referred to the genus Dinotherium^. 



Having since received specimens of portions of lower jaws with 

 teeth identical in structure with the fragment figured in my first 

 communication to the 'Annals^ (p. 9. figs. 2 and 3), I find that 

 the reference of that portion of tooth to the genus Dinotherium 

 was premature and erroneous. The extinct species to which it 

 belonged does, indeed, combine molar teeth like those of the 

 Dinotherium with two large incisive tusks in the lower jaw, but 

 these tusks incline upwards instead of bending downwards, and 

 are identical in form and structm-e with the tusk fi-om one of the 

 bone-caves of Wellington Valley, described by me in Sir T. j\lit- 

 chell's ' Expeditions into the Interior of Australia,^ vol. ii. 1838, 

 p. 362. pi. 31. figs. 1 and 2, as indicative of a new genus and 

 species of gigantic marsupial animal t, to which I gave the name 

 of Diprotodon aiistralis. 



It is not my present object to describe these most interesting 

 additional fossils of the Dijjrotodon, or to enter into the question 

 whether the great femur before alluded to belonged, like the 

 fragment of tooth transmitted with it, to the Diprotodon, or to a 



* Annals of Natural History, iSIay 1843, p. 329. fig. 1. 



f See also my paper " On the Classification of Marsupialia,"Zool. Trans, 

 vol. ii. p. 332, in Avhich the Diproladon is placed with the Wombat in the 

 family ' P/nmcolomyidiP.' 



