50 INTRODUCTION. 



eighteen species of Quadrupeds belonging to other 

 groups, it would appear that this continent has a rich 

 Mammalian fauna. Besides the native Dog, (which 

 it is supposed may have been introduced into Australia 

 with man,) and certain species of Seals and Bats, the 

 whole of the remaining placental Quadrupeds found 

 in Australia belong to the order Rodentia, and to one 

 particular group of this order — the Muridce * or 

 Rat-tribe. 



The above remarks refer only to recent species. 

 At former periods we have evidence that animals be- 

 longing to the Marsupiata had a much wider range — ■ 

 in fact they inhabited Europe as well as Australia 

 and South America. 



Cuvier has referred the remains of a small quadru- 

 ped, found in the Montmartre Gypsum, to the genus 

 Tiidelphys ;\ and he moreover gave it as his opinion,^ 

 that the ramus of a lower jaw, found in the Stones- 

 field oolite, belonged to an animal allied to the 

 Opossum. M. De Blainville has recently expressed 

 his doubts as regards the accuracy of this determi- 

 nation \X in consequence of which, Mr. Owen read 

 two papers before the Geological Society,§ answer- 



* Three new genera have been founded on the Australian 

 species of Rodents, — Hapalotis (commonly known in New 

 South Wales by the name " Native Ralhit^'') Pseudomys and 

 Hydromys, 



f " Annales du Museum," torn, v., p. 277, and " Ossemeus 

 Fossiles," torn, iii., p. 284, PI. 71. 



X "Comptes Rendus," 1838. 



§ See " Proceedings of the Geological Society of London," 

 vol. iii., 1 838-9. 



