52 VIEW OF THE FAUNA OF BRAZIL 



much less destructive form on the relics of their prey. Of 

 this class I need only remark, that the fragments are scattered 

 promiscuously together, and are enveloped in, and filled with, 

 earth. Moreover, they are often gnawed by the teeth of small 

 animals. 



The third kind of mechanical change which these bones 

 exhibit, is an abrasion of their points and angles, which, in a 

 former communication, I conceive that I have proved to be 

 attributable to the action of the water which formerly had ac- 

 cess to the caves wherein they are found. 



In all the cases of which I have hitherto spoken, the bones 

 have been protected from the action of the atmosphere, either 

 by their stalagmitic covering, or by lying in water. But 

 many have not been so favourably circumstanced. Many 

 have I seen which, from their peculiarly raised position in 

 the middle of a basin in the floor, have escaped being buried 

 in the soil ; and these present the most remarkable examples 

 of the destructive power of time. Their most exposed parts 

 are mouldered away, and changed into a yellowish dust, 

 which, by covering the inferior portions, has protected these 

 from decomposition. In those caverns where water has had 

 access in later periods, these fossil bones have occasionally 

 been torn out of their beds, and by the joint operation of water 

 and air, their decomposition has been so accelerated that they 

 resemble in appearance half-decomposed recent bones. This 

 has come under my notice at least once ; and had it not been 

 for the size of the bones, which indicated a much larger ani- 

 mal than any mammal now living in this quarter of the globe, 

 I confess I might have mistaken its age. Such, however, if I 

 may judge from my own experience, is seldom the case; at 

 any rate I can assure the Society that the above is the only 

 instance open to any doubt, among the fossils forming the 

 subject of this communication ; all the others were found 

 under circumstances that left not the slightest question as to 

 their origin. 



So much for the circumstances under which these fossils 

 are found and the changes they have undergone. But before 

 I proceed to a more accurate description of the animals to 

 which these remains belong, it will perhaps be advisable to 

 preface it with a few remarks on those existing species which 

 frequented or have left their traces in the spots that have af- 

 forded us so astonishing a catalogue of the creatures of a for- 

 mer world. / 



The first place on this list is due to the family of the bats. 

 There are few caves which do not harbour at least some in- 

 dividuals of this family : but to one who has not been an eye- 



