238 THE HISTORY OF CREATION. 



in the two sub-classes of Marsupials. According to this, 

 about eight orders of Marsupial animals may be dis- 

 tinguished, the one half of the main group or legion of 

 which are herbivorous, the other half carnivorous. The 

 oldest fossil remains of the two legions (if the previously 

 mentioned Microlestes and the Dromatherium are not 

 included) occur in the Jurassic strata, namely, in the 

 slates of Stonesfield, near Oxford. The slates belong to the 

 Bath, or the Lower Oolite formation — strata which lie directly 

 above the Lias, the oldest Jura formation. (Compare p. 15). 

 It is true that the remains of Marsupials found in the slates 

 of Stonesfield, as well as those which were found later in 

 the Purbeck strata, consist only of lower jaws. (Compare 

 p. 29.) But fortunately the lower jaw is just one of the most 

 characteristic parts of the skeleton of Marsupials. For it is 

 distinguished by a hook-shaped process of the lower comer 

 of the jaw turning downwards and backwards, which 

 neither occurs in Placental nor in the (stiU living) Cloacal 

 animals, and from the existence of this process on the lower 

 jaws from Stonesfield, we may infer that they belonged to 

 Marsupials. 



Of Herbivorous marsupials (Botanophaga), only two 

 fossils are as yet known from the Jura, namely, the Stereo- 

 gnathus ooliticus,from the slates of Stonesfield (Lower Oolite), 

 and the Plagiaulax Becklesii, from the middle Purbeck strata 

 (Upper Oolite). But in Australia there are gigantic fossil 

 remains of extinct herbivorous Marsupials from the diluvial 

 period (Diprotodon and Nototherium) which were far larger 

 than the largest of the stUl living Marsupials. The Diproto- 

 don Australis, whose skull alone is three feet long, exceeded 

 even the river-horse, or Hippopotamus, in size and upon the 



