110 STUDIES IN TASMANIAN MAMMALS, LIVING AND EXTINCT, 



as originally visualised. Upon the other hand, the great 

 palaeontologist hadf his share of success, correctly associating 

 the skull and jaws (that by reason of their apparent 

 anomalies acted as stumbling blocks to others for more 

 than half a century). Again, in the matter of the imper- 

 fect mandible, from South Australia, he instinctively 

 and with unerring accuracy separated it from the type 

 species; and seeing as in a glass darkly thei real signifi- 

 cance of the evolutionary trend ho listed the nasal septum 

 of both Diprotodon and Notoiherium, in the same category 

 with such structures in the Tichorhine Rhinoceros. As 

 some students of Professor Owen's works upon "Extinct 

 Mammals of Australia" appear to have missed the associa- 

 tion of Notoiherium with Diprotodon — and therefore with 

 the Tichorhine Rhinoceros — in this matter of the nasal 

 septum, it may be opportune to recall his actual data, re- 

 lating to this subject. At page 524 (part 3, Foss. Mam. 

 Aust.) he notes the development of the nasal septum of 

 Diprotodon — out of the ordinary marsupial anatomv — to 

 the condition that obtained in the Tichorhine Rhinoceros, 

 and again at page 51 of part 5, he links Notoiherium 

 with Diprotodon in this respect, remarking, inter alia, 

 that among the marsupials these two animals stand alone. 

 Ipso facto, therefore, both approached the extinct Peris- 

 sodactylan Ungulate, to a greater or lesser degree. We 

 now know that in the Leptocerathine group, the nasal 

 bones and nasal septum approached each other very close- 

 ly — while in the other group, the nasals receded for some 

 40 mm. in the male animal, but less in the female. 



RECAPITULATIVE NOTES. 



If the aim of our studies has been realised, we shall 

 have to some extent convinced zoologists, and palaeonto- 

 logists, of the fact that the Rhinoceros was not ansent 

 from the fauna of Australia in ages past. True to the 

 structural type of the country, these animals retained the 

 marsupial habit, simply grafting on to< it the results of that 

 evolutionary trend that has culminated in other lands 

 in the Perissodactylan Ungulates. Just how many groups 

 Australia, could boast of we arc at present unable to say,. 

 but apparently two, at least, were well segregated at the 

 time extinction overtook the race. One of these, the 

 Megacerathine group, manifested more development along 

 the fighting trend than the second, or Leptocerathine group 

 did. This is noticeable chiefly in the alterations to the 

 nasal bones for the attachment of the horn ; the extrav 

 strengthening of the neck ; the general enlargement of 

 the whole skeleton to maintain a suitable poise; the 



