266 PROFESSOR OWEN ON THE EOSSIL MAMMALS OF AUSTRALIA. 
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- 
sphenoid where that cavity is “indicated only by the internal orifices of 
the entocarotid canals” in Tliylacinus *. The chiasmal fossa is shown at o: 
the precondylar foramen at p.c. 
The symbols, letters, and numerals are explained in the text. 
List of Woodcuts. 
Fig. 1. Laniaries of Potamogale, front view. 
Fig. 2. Laniaries of Urotrichus, front view. 
Fig. 3. Mandible and upper and lower laniaries, side view, Potamogale. 
Fig. 4. Mandible and teeth of Thylacoleo, as restored by Professor Flower, front view, 
one-third nat. size. 
Fig. 5. Mandible and teeth of Phascolarctos, front view, three-fourths nat. size, after 
Professor Flower. 
Fig. 6. Mandible and teeth of Phascolarctos , side view, half nat. size : grinding-surface 
of molars, nat. size, after nature. 
Fig. 7. Skull of Thylacoleo carnifex , as reduced and restored by Professor Flower. 
Fig. 8. Mandible of Thylacoleo carnifex, one-fourth nat. size, after nature. 
Fig. 9. Mandible of Aye-aye, with incisor exposed, nat. size. 
Fig. 10. Mandible of Plagiaulax Falconeri, Ow., magnified 4 diameters. 
Fig. 11. Mandible of Tliylacinus cynoceplialus, after nature. 
Fig. 12. Mandible of Sarcophilus ursinus, after nature. 
Fig. 13. Skull of Thylacoleo carnifex, as reduced and restored by Mr. Krefft. 
Fig. 14. (Repetition of fig. 8.) 
Fig. 15. (Repetition of fig. 10.) 
Fig. 16. Mandible and teeth, Dendrolagus dorcocephalus. 
Fig. 17. Mandible and teeth, Hypsiprymnus minor. 
Fig. 18. Mandible and teeth, Bettongia penicillata. 
Fig. 19. Mandible and teeth, Phalangista Coolcii. 
Fig. 20. Mandible and teeth, recent and fossil carnivores, nat. size. 
* Descriptive Catalogue of the Osteological Series, &c., 4to, p. 349. 
