187 



Fig. 5. Right lower incisor, from a breccia-cave in Wellington Valley, outer side view. 

 Fig. 6. Right lower incisor, from a breccia-cave in Wellington Valley, inner side view. 

 Fig. 7. Right lower incisor, from a breccia-cave in Wellington Valley, back view. 

 Fig. 8. Right lower incisor, from a breccia-cave in Wellington Valley, transverse section, 



one-third from apex of crown. 

 Fig. 9. Right lower incisor, from a breccia-cave in Wellington Valley, transverse section 



of base of crown. 



The subjects of the foregoing figures are from Thylacoleo carnifex, nat. size. 

 Fig. 10. Left mandibular ramus and teeth, Bettongia^ nat. size. 



Fig. 11. Inner side view of a sheathed ungual phalanx (claw-core exposed by the re- 

 moval of part of bony sheath) of an unguiculate mammal. 



Fig. 12. Outer side view of a similar ungual phalanx, with more of the bony sheath 

 preserved. 



Fig. 13. Side view of a similar ungual phalanx; sheath mutilated. 



Fig. 14. Under view of the same phalanx. 



(From "photographs:" the originals in the Museum of Natural History, 

 Sydney, New South Wales, were obtained from the same breccia as the 

 subjects of figs. 1 and 2, and are from a large carnivore, probably of the 

 same species.) 



PLATE X. 



Section of the skull of Thylacoleo carnifex as at present known, showing the 

 cerebral cavity and the entire dentition from nature, nat. size. Owing 

 to the crowding of the abortive premolars {p i, 2, 3) to the inner side of 

 the functional one {p 4), a complete view of the dental system cannot be 

 had from the outer side of the jaws: if illustrated from that point of 

 view it must be more or less diagrammatically ; this Plate is, therefore, 

 added, to be contrasted, as to number and relative size and position of 

 the teeth, with the restorations which have been published in support of 

 the herbivorous hypothesis of Thylacoleo. I have refrained from com- 

 pleting anatomically the articular part and ascending ramus of the man- 

 dible : one cannot doubt but that, ere long, an entire mandibular ramus of 

 Thylacoleo carnifex will be obtained. The section of the cerebral cavity 

 confirms the ascription of the extinct carnivore to the Lyencephalous 

 subclass. The cerebellum, as in JDasyurus, rises wholly behind the 

 cerebrum, with apparently the interposition of part of the mesencephalon 

 The prosencephalon (pr) is very small when its proportion to the entire 

 skull is compared with that in the Lion or Tiger. The rhinencephalon 

 (rh), projecting and conspicuous anterior to the cerebrum, is character- 

 istically large. A " sella" (h) is plainly indicated at the part of the basi- 



