181 



we get the following results. The length from the fore part of the laniary to the hind 

 part of the carnassial, upper jaw, is in Felis tigris 3 inches 7 lines; in Felis spelcea 

 4 inches ; in Thylacoleo camifex 4 inches 3 lines. In the lower jaw the proportions are 

 reversed ; but the difference affords no reasonable ground for inferring such inferiority 

 of strength or destructive power as to support the inference that Thylacoleo was inca- 

 pable of playing the same part in relation to the Nototheres and Diprotodons as the Lion 

 now performs in relation to the Buffaloes and Giraffes. 



The remains of the large extinct Herbiwra 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, Xototheres, 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 Diprotodon and Kotothe- 

 rium as the spelsean Lion, Bear, and Hysena bore to the Mammoths, Rhinoceros, Oxen, 

 &c, has hitherto been detected in Australian bone-caves, save the Thylacoleo camifex. 

 To its associated fossils, the Thylacine or the Dasyure (Sarcophilus), the objection of 

 defective strength and bulk might be specious, but, as applied to the Thylacoleo, it is 

 absurd. 



In the main the descriptions or definitions of the characters of the fossil remains of 

 Thylacoleo 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 immediately 

 below the neck of the condyle as in Sarcophilus and Thylacinus, whilst Dr. Falconer 

 contends that the part broken away descended below the condyle as in the mandible 

 of the Aye-aye. And so, with regard to Thylacoleo, 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 

 Thylacoleo, 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- 



10 



