SIR R. OWEN ON THE AFFINITIES OF THTLACOLEO CARNIFEX. 



3 



as many vertical grooves on the side of the crown terminate. Moreover, the so 

 modified premolar is followed in the vegetarian Diprotodonts by four broad-crowned 

 bruising teeth, instead of the suddenly reduced couple of conical molars [m, 1 and 2, 

 figs. 1 and 2, Plate 1) by which Thylacoleo resembles the placental Leonines. I view 

 with interest the engrafting of a carnivorous modification upon a marsupial type of 

 teeth and bone in a species equal as to size and force to grapple with and slay its 

 ancient vegetarian contemporaries — the greater herbivorous Diprotodonts and Noto- 

 theriums, the large, now extinct, Kangaroos, Sthenurus, Protemnodon, and the huge 

 extinct Wombats (Phascolonus) — types of pouched mammalian families, surpassing in 

 bulk any of the allied still existing species. 



The picture of mammalian life in the Australian continent paralleled, of old, that 

 still manifested in Asia and Africa : huge herbivorous quadrupeds were kept in check 

 by large and powerful carnivorous ones, but both were represented by species of a 

 lower grade of organisation ; and the inferior cerebral development of the Marsiqnalia 

 may be taken into account when we attribute to the advent in Australia of the 

 Bimanous race the extirpation of the beasts afibrding the greatest quantity of animal 

 food, and the consequent reduction of the pouched families to such smaller existing 

 species a,s are still able to escape by conceahnent in burrows, trees, and brush forests. 



Addendum. 



(Added 22nd December, 1886.) 



Since communicating the foregoing Paper, I have received from George Frederic 

 Bennett, Esq., Corresponding Member of the London Zoological Society, a large 

 portion of a mandible of Thylacoleo carnifex, discovered in the post-pliocene bed of 

 King's Creek, Toowoomba, Queensland, Australia ; it is in the same semi-fossilised 

 condition as the Diprotodont remains from that locality. 



The specimen may be seen, together with the cast of the entire mandibular ramus 

 from the Wellington Valley Cave, New South Wales, in the Geological Department 

 of the British Museum of Natural History, Cromwell Road. 



K. O. 



Description of the Plate. 



Fig. 1. Mandible of Thylacoleo carnifex, nat. size, outside view. 



Fig. 2. Mandible of Thylacoleo carnifex, nat. size, inside view. 



Fig. 3. Hind end of mandibular ramus of Thylacoleo carnifex, nat. size. 



(References to parts in these figures are explained in the text.) 



B 2 



