PURBECK FORMATIONS. 107 



The proportions are reversed in Felines ; but the difference affords no reasonable 

 ground for inferring such inferiority of strength or destructive power as to support 

 the inference that Tliylacoleo was incapable of playing the same part in relation 

 to Nototheres and Diprotodons as the Lion now performs in relation to Buffaloes and 

 Giraffes. 



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, in most cases, 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 fresh-water 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. Now, no species bearing such pro- 

 portion to the Dijn-otodon and Nototherium, as the spelaean" Lion, Bear and Hyaena, bore to 

 the Mammoths, Rhinoceroses, primigenial Oxen, huge Deer,- &c., in Europe, has hitherto 

 been detected in Australian bone-caves, save the Thylacoleo carnifex. To its associated 

 carnivorous cave-fossils, the Thylacine, or the Dasyure {Sarcophilus), the objection of 

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

 simply absurd. 



A comparison of fig. 15, p. 93, with fig. 12", p. 90, will show, by the obvious similarity 

 of their subjects, that a refutation of the asserted herbivority of Thylacoleo is associated 

 with the grounds of the interpretation submitted, in the present Monograph, of the 

 Playiaidax as a marsupial Carnivore allied to the later, larger, and more specialised 

 carnivorous Thylacoleo. 



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

 Playiaulax by my antagonists and myself are the same : the chief difference herein is, 

 that I interpret the fractured surface of the angle of the jaw in a specimen of Playiaulax 

 Becklesii (PL IV, fig. 10, a) as indicative of that part having been bent inward 

 immediately below the neck of the condyle as in Surcophilm (fig. 20, a) and Thylacinus 

 (fig. 5, a) ; whilst Dr. Falconer contends that the part broken away descended below 

 the condyle as in the mandible of the Aye-aye (fig. 19, «). To elucidate this discrepancy 

 as to matter of fact, I have reproduced, in fig. 12, p. 90, the magnified view of the 

 mandible of Plagiaulax given by Falconer (loc. cit.), of a specimen which I have not 

 seen, and hold it to be confirmatory of my deductions from the specimens (PI. IV, figs. 9 

 — 15) which I have carefully scrutinised. 



So likewise with regard to Thylacoleo, I interpret the evidences of the fossil mandible 

 (fig. 15) as indicative of an agreement with Playiaulax, and with existing Marsupial 

 Carnivora, in the form and proportions of the coronoid process, and the indication of the 

 low position of the condyle and its proximity to the inflected angle of the jaw. 



