HO 



fJUIDE TO THE FOSRIT, MAMMALS AND I'.IIJDS, 



Table-case tropics, lived with the Creodunta both in Eui-upc aud Xuilli 

 ^ America, while other undoubted little pouched animals, 



such as EiKiiiornuis, accompanied the Sparassodonta aud 

 early opossums in South America. Jaws of these small 

 marsupials, some from the LoM'er and Upper Eocene of 

 Enj,dand, and from the Lower ]\Iiocene of Erance, are shown 

 in Table-case 14a. A few South American jaws are aiTanged 

 with them. 



Erom these and other con.si derations it seems likelv that 



m^i^- 







Fig. 74. — Lower jaw and teeth of Triconodon mcrdax, from the Purbeck 

 Beds of Swanage; nat. size. (Table-case 14.\.) 



Table-ease 

 14a. 



Fig. 75. — Part of lower jaw and teeth of Spalacotherium triciispidens, 

 from the Purheck Beds of Swanage ; outline-fig. nat. size, c and d 

 being lateral and upper views of a molar tooth. (Table-case 14a.) 



the Australian legion has remained isolated from the rest of 

 tlie world since the end of the Secondary epoch, and that its 

 marsupials are the slightly altered survivors of the mammal - 

 life then characteristic of every continent. 



Tlie only known mammals of the Secondary or .Mesozoic 

 epoch are creatures about as large as rats, whose jaws and 

 limb-bones have been found in the Upper Cretaceous and 

 Jurassic rocks of Xorth America, and in the Jurassic 

 (Purbeck Beds and Stonesfield Slate) of England. Most of 

 them seem to have Ijeen insectivorous marsupials, and one 



