308 PKOCEEDIIfGS OP THE GEOLOGICAL SOCLETY. [April 8, 



feeder, and the other that it was a predaceous carnivore ? Or does 

 the conflict of opinion arise from different methods having been 

 followed by the observers in dealing with the evidence ? " He con- 

 cludes that the question will not rest in its present disputed state. 

 " Other palaeontologists ^oU examine the evidence, and give their 

 verdict." 



Por my part, I cannot hesitate to express my full conviction of 

 the soundness of Dr. Falconer's views, as far as may be deduced from 

 the evidence before us. There is one point, however, referred to 

 incidentally but frequently in the course of his paper, on which I 

 am obliged to differ from that distinguished palaeontologist, without 

 in the slightest degree wishing to impugn his well-known and justly 

 esteemed acumen and discernment in such matters ; for it is a 

 point on which he had evidently never concentrated those powers 

 of mind which led him to so logical a conclusion in the closely 

 reasoned case of Plagiaidax. 



This animal had been associated by Professor Owen with TTiyla- 

 coleo, " a much larger extinct predaceous marsupial from Tertiary 

 beds in Australia"*. Dr. Falconer, in his anxiety to show that 

 Plagiaulax could not have been carnivorous, has endeavoured to 

 separate it as much as possible from Thylacoleo, laying great empha- 

 sis on all the points of divergence that could be found between 

 them. He was evidently under the impression that the latter had 

 been proved to be a carnivorous marsupial, without staying to in- 

 quire into the arguments on which the assumption rested — the 

 real fact, however, being, as I shall endeavour to show, that the 

 affinities of Plagiaulax and Tliylacoleo, correctly discerned by Pro- 

 fessor Owen, tend rather to strengthen, instead of detracting from, 

 Dr. Falconer's main argument. 



The history of the last-named remarkable animal is as follows : 

 — In a paper in the Philosophical Transactions for 1859 (p. 309), 

 under the title " Description of a mutilated skull of a large Marsu- 

 pial Carnivore (^Tliylacoleo carnifex, Owen) from a calcareous con- 

 glomerate stratum, eighty miles S.W. of Melbourne, Yictoria," Pro- 

 fessor Owen gave a detailed and illustrated description of a speci- 

 men, discovered by Mr. W. Adeney, and presented, in 1846, to the 

 Museum of the Eoyal College of Surgeons, by Dr. Hobson, of Mel- 

 bourne, proving beyond question its marsupial character, and stating 

 that " the chief conclusion as to the affinities of the animal to 

 which they the [fossil remains] belonged had been indicated by 

 the term Thylacoleo, i. e. Marsupial or Pouched Lion," and that 

 " amongst existing Marsupialia the Sa7Xoj>hilus, or Dasyurus ursinus 

 — at present the largest existing species of its genus — seems to me to 

 have the nearest affinities to the Thylacoleo, although the interval be 

 still very great between them." It was further stated in this paper, 

 " From the size and form of the carnassials of Thylacoleo, especially 

 the upper one, we may infer that it was one of the fellest and 

 most destructive of predatory beasts." 



In a later volume of the Philosophical Transactions (1866, p. 73), 

 ^ Owen, ' Palgeontology,' 2nd edit. p. 354 (1861). 



