404 PETKIFACTIONS AND THEIR TEACHINGS. CHAP. IV. 



These mammalian jaws belong to very small animals, and are 

 referable to two genera. One of these, the Ampfiitherium, 

 appears to have been an insectivorous mammal j it had thirty- 

 two teeth (twelve molars, one canine, three incisors) in the 

 lower jaw ; its marsupial affinities are doubtful. 1 



The other genus, Phascolotherium, presents in its dental 

 and maxillary organs the true characters of the Marsupialia. 

 Baron Cuvier pointed out the extent and position of the 

 inward inflection of the angular process of the lower jaw 

 observable in the fossil, as indicating its marsupial affinities ; 

 for in the placental mammalia the same degree of incurvation 

 is not present. This fossil mammalian has four true molar 

 teeth, three false molars, one canine, and four incisors (three 

 only remain in the specimen), in each ramus of the lower 

 jaw; thus agreeing with the living species of Didelphys. 



LIGN. 80. RIGHT SIDE OF THE LOWER JAW OF A MARSUPIAL MAMMALIAN; 

 FROM STONESFIELD. 



(Phascolotherium Bucklandi.) 

 (Inner aspect; nat. size.) 



The condyle of this jaw presents the same form and degree of 

 convexity as in the genera Didelphys and Dasyurus; the 

 general shape and proportions of the coracoid process resemble 

 those in the zoophagous marsupials ; but in the depth and 

 form of the entering notch between this process and the con- 

 dyle, it corresponds most closely with the Thylacinus, a 

 solitary genus of Australia (the Hyena of the colonists), 



1 " Amphitherium JBroderipii" of Professor Owen. See "British 

 Fossil Mammals," pp. 2970, for figures and an elaborate account of the 

 Stonesfield Mammalia. 



