MAMMALIA. 



341 



in existing Mammalia, but is as well adapted for crushing the 

 cases of coleopterous insects (elytra of which are found fossil 

 in the same oolitic matrix) as are any of the multi-cuspid 

 molars of small, opossums, shrews, and bats. The Amphilestes 

 Broderipii was somewhat larger than Arn/phifherLum Prevostii. 



Genus Phascolothepjum. — Although the evidence of the 

 very slight degree of inflection of the angular process of the 

 lower jaw of Amphitherium may favour its affinity to the 

 placental Insectivores, yet the range of variety to which that 

 mandibular character is subject in the different genera of 

 existing Marsupialia warns us against laying undue stress 

 upon its feeble development in the extinct genus of the oolitic 

 epoch, and incites us to look with redoubled interest at what- 

 ever other indications of a marsupial character may be present 

 in the fossil remains of other genera and species of Mammalia 

 that have been detected in the Stonesfield slate. 



In the specimen of Phascoloiherium (fig. 113), the marsupial 



Fig-. 113. 



Lower jaw and teeth of the Phascolotherium (nat. size in outline), 

 Lower Oolite. 



characters are more strongly manifested in the general form of 

 the jaw, and in the extent and position of the inflected angle, 

 while the agreement with the genus Didelphys in the number 

 of the premolar and molar teeth is complete. The forms of 



