PROFESSOR OWEN ON THE FOSSIL MAMMALS OF AUSTRALIA. 
261 
The remains of the large extinct Herbivora of the Pleistocene period in Britain, which 
have been found in the limestone-caves of Weston-super-Mare, Torquay, Pickering, &c., 
are held to have been parts of animals which have fallen a prey to the contemporary 
Carnivora , now also extinct. The caves of the limestone-district of Wellington Valley, 
Australia, reveal phenomena of extinct animal life closely analogous. I infer that the 
fossils, always more fragmentary than those from the tranquil freshwater deposits, of the 
Diprotodons, Nototheres, large Kangaroos, and Wombats, surpassing in size any existing 
species, were remains of animals which had fallen a prey to contemporary Carnivora , 
and by them had been dragged into the cave. 
Now, no predaceous species bearing such proportion to the Hiprotodon and Notothe- 
rium as the spelaean Lion, Bear, and Hyaena bore to the Mammoths, Rhinoceros, Oxen, 
&c., has hitherto been detected in Australian bone-caves, save the Tliylacoleo carnifex . 
To its associated fossils, the Thylacine or the Dasyure ( Sarcophilus ), the objection of 
defective strength and bulk might be specious ; but it is inapplicable to the Tliylacoleo. 
§ 19. Conclusion. — In the main the descriptions or definitions of the characters of the 
fossil remains of Tliylacoleo and Plagiaulax by my antagonists and myself are the same ; 
and the chief difference herein is that I interpret the fractured surface of the angle of 
the jaw in a specimen of Plagiaulax as indicative of that part being bent inward imme- 
diately below the neck of the condyle as in Sarcophilus and Tlvylacinus , whilst Dr. Fal- 
coner contends that the part broken away descended below the condyle as in the man- 
dible of the Aye-aye. And so, with regard to Tliylacoleo , I interpret the evidences of 
its fossil mandible as indicative of an agreement with that in existing Marsupial Carni- 
vora in the form and proportions of the coronoid process and in the position of the 
transversely extended condyle. Messrs. Krefft and Flower restore the mandible of 
Tliylacoleo , in regard to these light-giving structures, according to the analogies of the 
carpophagous Phalangers and Koalas and the poephagous Potoroos, assigning to the 
upper jaw the same incisive formula, for dissenting from which I have given reasons. 
I cannot find better words to express my conviction of the state of the question as now 
analyzed and tested than those of the gifted and lamented Palaeontologist, whose criti- 
cisms, as reproduced in his posthumous work, reiterated, as it were, from the grave, have 
overcome the reluctance which, till now, has kept me silent. In those words, therefore, 
I venture to remark, that, if my inferences and conclusions be favoured by acceptance, 
it will not imply that my opponents had “ fallen into errors of observation and descrip- 
tion”*, so much as it will expose “ the fallacious train of reasoning which had led them 
astray ”f. 
Should Tliylacoleo be permitted to rest, after the facts and inferences from the scanty 
fossil evidences at my command, in the section of diprotodont Marsupials, with Plagi- 
aulax, amongst the predaceous feeders on flesh, and not with Hypsiprymnus amongst the 
harmless Herbivora , it will only be further proof of the worth and truth of the principle 
which Cuvier laid down as our guide in such dark routes in Palaeontology. 
* X. p. 350 ; XI. p. 433. f Id. ib. 
2 N 
MDCCCLXXI. 
