434 



agree, in the state of preservation, and in the substance with which they 

 are invested, with those of the bears, and of the hyenas. Similar bones 

 have been found with the elephantine remains at Canstadt and at Ro- 

 magnano; and at Kahldorf, where the head of the hyena already men- 

 tioned, described by Collini, was found. 



The quantity of remains of animals of the former world which has 

 been imbedded in the quarries of plaster-stone in the neighbourhood of 

 Paris, must be beyond conception. Considering that, in certain beds, 

 there is not a block of gypsum but which encloses perhaps a bone, how 

 many millions of these bones, as is justly observed by Cuvier, must have 

 been destroyed by the vast excavations which have been already made ? 

 how many more are being perpetually lost through mere neglect ? and, 

 even since they have been more in request, how many must escape ob- 

 servation in consequence of their minuteness ? 



To such observations the indefatigable Cuvier was led, by the dis- 

 covery of a skeleton of a small size, in two pieces of gypsum. By a care- 

 ful dissection, as it were, of these stones, he was enabled to make out the 

 different parts' of the skeleton so distinctly, as to ascertain that it was one 

 of the animals of the family of Pcdimanes of Dumeril, which are distin- 

 guished by having a separated toe to their hind foot, and a fold of 

 the integument forming a pouch beneath the belly ; or, as it were, a 

 false uterus. 



The animals of this description are disposed, in the last edition of 

 Systema Nature, in thirteen species, under the genus Didelphis. This dis- 

 posal, according to M. Cuvier, is not correct. Independent of other 

 objections, which will be presently noticed, it is to be remarked, that 

 Dr. Shaw has found it necessary to separate from these the kanguroo, 

 Didelphis gigantea, Linn, and has formed 'of it a distinct genus, to 

 which he has given the name Macropus ; the animals of which transfer 

 their young, even before they are fully formed, to a pouch beneath their 

 belly, or carry them, when formed, on their backs. 



M. Cuvier divides the genus Didelphis into the following subgenera : 



