382 PALEONTOLOGY AND EVOLUTION il 



sida and Marsu2ncdia which constituted that fauna 

 were, I doubt not, the progenitors of the Sauropsida 

 and Marsuinalia of the whole Mesozoic epoch. 



Looking at the present terrestrial fauna of 

 Australia, it appears to me to be very probable 

 that it is essentially a remnant of the fauna of the 

 Triassic, or even of an earlier, age ; ^ in which case 

 Australia must at that time have been in continuity 

 with the Arctogseal continent. 



But now comes the further inquiry, Where was 

 the highly differentiated Sauropsidan fauna of the 

 Trias in Palaeozoic times ? The supposition that 

 the Dinosaurian, Crocodilian, Dicynodontian, and 

 Plesiosaurian types were suddenly created at the 

 end of the Permian epoch may be dismissed, with- 

 out further consideration, as a monstrous and un- 

 warranted assumption. The supposition that all 

 these types were rapidly differentiated out of 

 Lacertilia in the time represented by the passage 

 from the Palaeozoic to the Mesozoic formation, 

 appears to me to be hardly more credible, to say 

 nothing of the indications of the existence of 

 Dinosaurian forms in the Permian rocks which 

 have already been obtained. 



For my part, I entertain no sort of doubt that 

 the Reptiles, Birds, and Mammals of the Trias are 

 the direct descendants of Reptiles, Birds, and 

 Mammals which existed in the latter part of the 



^ Since this Address was read, Mr. Krefft has sent us news of 

 the discovery in Australia of a freshwater fish of straugily 

 Palaeozoic aspect, and apparently a Ganoid intermediate between 

 Dipterus and Lepidosiren. [The now well-known Ceratodus. 189 'L.] 



