DIDELPHYS. 75 



Chiroptera., and the small placental or marsupial Insec- 

 tivora. In this category, the breadth of the coronoid 

 process a character equally developed in our small oolitic 

 Mammalia and the inward bending of the angle of the 

 jaw, left no doubt in the mind of Cuvier of the affinity of 

 the fossil to the small marsupial Insectivora, among which 

 it offered the closest resemblance in the shape of the teeth 

 to the Opossums. 



But one of the strictest instances of the generalizations 

 which Buifon had enunciated respecting the geographical 

 distribution of animals, was the limitation of the true 

 Opossums, (Didelphys, Cuv.,) to the American Continents, 

 and the triumphs of the comparative anatomist, by the 

 fulfilment of predictions founded on fragmentary begin- 

 nings, had not at that time occurred so frequently, as 

 not to render it desirable to dispel any lurking scepti- 

 cism in the minds of the scientific contemporaries of Cu- 

 vier by the demonstration of the marsupial bones them- 

 selves. These, in the genus Didelphys, are two slen- 

 der, moderately long, flat bones, extending forwards from 

 the fore part of the pelvis ; and this part of the skeleton 

 of the little animal in question was buried in the block of 

 gypsum. 



Cuvier had successively appreciated and demonstrated 

 the characters which enabled him to pronounce as to the 

 class, the subclass, the order, and, as he believed, the par- 

 ticular family to which the small Eocene quadruped had 

 belonged ; but the best proof of the accuracy of his deter- 

 mination was hidden in the stone. He thereupon called 

 together a few friends, capable of appreciating the trial : 

 he laid before them the recent skeleton of a small Opos- 

 sum, and, predicting the result of his operations, commen- 

 ced the removal of the matrix of the Montmartre fossil 



