1G8 



was dieted on bread and milk. " In its native grassy haunts its food consists of insects 

 and their larva', and the roots of trees and plants"*, for the mastication of which its 

 broad flat grinders f are well adapted. Nevertheless the canines proper are separated 

 in the upper jaw by not fewer than ten incisors, and in the lower jaw by six incisors J. 



The cloven-footed Chcerqpus, equally polyprotodont, but with digital characters more 

 closely resembling those of the Artiodactyle Ungulates than in any other marsupial 

 genus, is not carnivorous. The condition of the molars associated with the " three or 

 more incisors followed by a canine on each side of the jaw," clearly points to that fact. 

 The accomplished naturalist and explorer of Australian haunts of animal life thus tes- 

 tifies of Chceropus castanotis: — "As its dentition would indicate, its food consists of 

 insects and their larvae, and of vegetable substances of some kind, probably the bark of 

 trees and tuberous roots''^. 



In fact the parallel and convergent modifications of all those structures which truly 

 influence and indicate the food and habits of the animal have been noticed by all who 

 have devoted the requisite attention to the Marsupial order. Gould well remarks, 

 " Ihjjisiprymni grub the ground for roots, and live somewhat after the manner of Pera- 

 melides, with which, however, they have no relationship" || ; meaning within the ordinal 

 limits — the one group being "diprotodont," the other "polyprotodont," with modifications 

 of the two subordinal types bringing them to close similarity, if not identity, of locomo- 

 tion, diet, and mode of obtaining food. 



In the case of a fossil mandible of either genus the palaeontologist, referring to the 

 molar teeth, would be led to the like inference as to food and habits, although he would 

 see in one a pair of large approximate incisors and no canines, in the other canines 

 with small incisors interposed. 



Fig. 14. Fig. 15. 



) c 



Mandible and teeth, Plagiaulcuc, magnified 4 dia- 

 meters. (After Falcoxek, Quarterly Journal of the 

 Geological Society, vol. xiii. 1857, p. 280, fig. 14.) 



Thylacoleo (fig. 14) and Plagiaulax (fig. 15) more closely resemble each other in 



* Gottld, torn. cit. {PeragaUa lagotis). 



t Cyclopaedia of Anatomy, vol. iii. (1841), Art. " Marsvpialia," p. 274, fig. 96. 



t lb. Art. " Marsvpiaiia," ut supra. § GofLD, ' Mammals of Australia,' vol. i. ( Chmropus). 



Id. ib. Introduction, p. xix. 



