114 FOSSIL MAMMALIA OF THE 



contemporaneously with Brotnafherium and AmpJiitJierium in other and far distant parts 

 of the earth, and with them to have become extinct ; let us also suppose that our know- 

 ledge of such Australian Mesozoic INIammals depended, as in America and Europe, on the 

 acquisition of their fossilized remnants in Triassic or Oolitic rocks. What, it may be asked, 

 would be the chances of the geologist hitting upon the exceptional Mynuecobian ? 



At the dates of the publications of the works of Waterhouse and Gould on 

 Australian Marsupials, the Poephaga (kangaroos, potoroos, &c.) numbered forty-three 

 species ; the lihizophaga (wombats) three species ; the Carpophaga (phalangers, 

 petaurists, koalas) twenty-two species; the typodentate Entomophaga (bandicoots, &c.) 

 ten species ; the Sarcophaga (thylacines, dasym'es, phascogales) twenty-one species. 



The probability is that the specially modified diprotodont dentition of the saltatorial 

 herbivorous Kangaroos and Potoroos, since thdr numerous species are represented by more 

 numerous individuals than are the species of the flesh-feeders, would be exemplified in 

 the fossil series in a like numerical proportion with the multidentate polyprotodont genera 

 in British Mesozoic beds. 



Evidence, however, of Mammalian life from the corresponding epoch in AustraUa has 

 yet to be obtained. 



If the correlative Rhsetic and Oolitic rocks there exist, entombing relics of the 

 Mammals of the period, analogy would lead us to expect results like tliose now obtained 

 from the study of the Mesozoic fossils of Europe and America. 



Our knowledge of the extinct Australian Mammals has been hitherto supplied by 

 fresh-water deposits and caves ; and these, like the correspondingly recent graves of 

 European Quaternary Mammals, yield evidence of progress to great diversity and 

 specialisation of structures ; manifested, moreover, in many species, with magnitudes 

 indicating the favorable conditions under which Diprotodons, Nototherians, Thylacoleons, 

 gigantic Kangaroos, Wallabees, and Wombats ranged and flourished before the advent in 

 Australia of the destructive and all-conquering archencephalous biped. 



By that which it has been my present aim to make known — the number and nature 

 of British Mesozoic Mammals — and through considerations to which their contemplation 

 has given rise, my beUef has been strengthened in the Law of the Progress from the 

 General to the Special, from the low to the high. It is illustrated in the succession of 

 Mammals from the Trias upwards, as it is by that of other classes from the dawn of life 

 {Eozoon) to the present period. 



