PROFESSOR OWEN ON THE FOSSIL MAMMALS OF AUSTRALIA. 
215 
The teeth in the lower jaw are the root and base of the crown of the incisor (£), and 
the entire carnassial (p i). 
I was thus still driven, as far as these specimens went, to an inferential conclusion as 
to the form of the crown of the anterior incisor, both above and below. But, since pre- 
paring for the Royal Society a description of the specimens, I have been favoured by 
photographs and fossils of both these teeth nearly complete, and also with a plaster 
cast of the entire lower incisor, now in the Museum of Natural History at Sydney, New 
South Wales, through the kindness of the Trustees of that Museum and of their able 
Curator, Mr. Gerard Krefft, Corr. M.Z.S. 
The teeth transmitted and the subjects of the photographs were obtained from the 
Breccia-cave in Wellington Valley*, in the course of recent assiduous researches con- 
ducted by Alex. M. Thomson, D.Sc., Reader on Geology, Sydney University, and by 
Mr. Krefft, in 1869, aided by the liberal grant of £200 voted by the Local Parliament 
of New South Wales in favourable response to the Memorial which I addressed to the 
Colonial Secretary, February 23rd, 1867f. 
Whatever interpretation may ultimately be accepted in paleontology of the habits 
and affinities of Thylacoleo , additional and valuable materials for such interpretation 
have thus been added to the subjects of former descriptions: an account of these addi- 
tions, with their bearing on the arguments that have been opposed to my conclusions, 
I have now the honour to submit to the Royal Society. 
§ 2. Upper Jaw and Maocillary Teeth. — The specimen of this part of the skull 
(Plate XI.) includes almost the entire premaxillary (figs. 1-5, 22 ), with its alveolar ( a , a!), 
nasal (n), and palatal ( p ) portions. 
The alveolar portion contains the socket (a) of the anterior large laniariform incisor 
(i 1 ), that of a much smaller incisor (i 2 ) opening close to the first, and, after an interval 
of two lines, the front half of the socket (c) of a small canine (fig. 9), the division of 
which socket is made, or rather indicated, by the premaxillo-maxillary suture (s, s') : 
this third socket is rather larger than the second, and is more outwardly placed. 
The nasal portion of the premaxillary forms anteriorly, above the deep socket of the 
first incisor, a thick obtuse margin (fig. 4, 22 ), convex transversely, concave vertically and 
also laterally toward the nasal cavity (ib. n) ; it becomes much thinner above the socket, 
then regains thickness at its upper part, where the plate arches inward to join the nasal 
bone. A ridge (r) for the attachment of the inferior “ turbinal ” divides the fore part of 
the nasal chamber into an upper (n) and a lower (p!) passage. 
The palatal process (figs. 2 & 3, p 22 >) is thick and short ; it projects forward about 
four lines in advance of the first large alveolus (fig. 1 , p%), is grooved above, lengthwise, 
where it forms that part of the floor of the nostril, n' ; and it is also grooved or chan- 
* Discovered by Colonel Sir Thomas Mitchell, C.B., F.G.S., and described in his work, ‘ Three Expeditions 
into the Interior of Eastern Australia,’ 8vo, vol. ii. 1838. 
t “ On the Fossil Mammals of Australia. — Part III.,” Philosophical Transactions, 1870, p. 569. 
+ As shown in the subject of the Memoir, Philosophical Transactions, 1866, Plate 11 . 
2 g 2 
