316 Mr. R. Etheridge, Jnr., on 



guided by Pi'of. E. C. Stirling's reconstruction of Diprotodon, 

 resemble to some extent those of the Kangaroos, plano- 

 convex, slightly curved, broad plantar surface, and the 

 proximal concavities occupying the whole articular surface, 

 instead of about two-thirds as in Types 1 and 2; moreover, 

 the position of the foramina of the plantar artery branches 

 is markedly different. What is true of the nail-bones of 

 Diprotodon is possibly equally true of those of Nototherium 

 and Euowenia. 



There remain the Dasyuridae and Phalangeridpe. In the 

 first, taking the Tasmanian Wolf {Thylacinus cynocephalus, 

 Harris) as an example, the nail-bones are long, more or less 

 oval in section, rapidly decreasing in size from the proximal 

 to the pointed distal end. The latter are more particularly 

 accentuated in the Tasmanian Devil (Sarcophilus ursinus, 

 Harris, PI. XIX. fig. 14), in which the distal ends of these 

 nail-cores are to all intents and purposes, acicular ; hence, 

 I dismiss the Dasyuridse from consideration. 



This reduces comparison to the Phalangeridse, the family 

 in which Krefft placed "* these remains. The resemblance 

 of the large complete specimen (P\. XX. figs. 10-12) from 

 Cope's Creek to similar bones of some members ot this 

 family is very striking. For the purpose of comparison 

 I have selected two, the Great Flying Phalanger (Petaiiroides 

 volans, Kerr) and the Koala, or " Native Bear " (Phasco- 

 larctos cinereus, Goldfuss) f. In the Flying Phalanger it is 

 the 4th and 5th digits which terminate in nail-bones so 

 remarkably like the Cope's Creek fossil (PL XX. figs. 10-12), 

 but in the Koala the resemblance is not so strong (PI. XIX. 

 fig. 13), in consequence of the much greater length in 

 proportion to. width; this, however, only partially holds 

 good for the pollices J. With these facts before me I can 

 come to no other conclusion than that the subjects of 

 Pis. XIX.-XX. figs. 8-12 are the terminal phalanges of an 

 enormous Phalanger, following Krefft in this opinion, but 

 in a more restricted sense than he employed the term. 



We may now pass to the second type (Pis. XVIII.-XIX. 

 figs. 2-7) . The two specimens are Krefft's " large nail-bones 



* Bearing in mind that Krefft included Diprotodon, &c, in this 

 family. 



t One fact in connection with the terminal phalanges, or nail-bones, 

 of the Phalangers in general is very obvious, the stouter and stronger 

 build of those of the fore feet, accompanied with a greater degree of 

 curvature. 



X One of the most noticeable features in Type 1 is the remarkable 

 slab-sided, or straight-walled appearance. 



