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 stances of the generalizations 
which Buffon 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 
