14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 59 



Chicago. In the I3th Annual Report of the Indiana Geological 

 Survey, on page 143, it is stated that some years ago the tooth of a 

 mastodon was found in one of the marshes south of the lake in the 

 eastern part of Fairmount township, a lake that has been greatly 

 reduced, now possibly obliterated, since the time of settlement of the 

 region by white men. 



The Pleistocene fauna which occupied our country before Wis- 

 consin time differed in many respects from that of the Wabash 

 stage. It embraced edentates of several extinct genera, Megather- 

 ium, Mylodon, Megalonyx, and Paramylodon; horses of several 

 species ; a number of genera and species of camels ; tapirs ; bisons of a 

 number of extinct species ; peccaries belonging to the genera Platyg- 

 onus and Mylohyus; bears of the extinct genus Arctodus and extinct 

 species of Ursus; saber-tooth cats of more than one genus ; some 

 extinct dogs ; and various other forms, besides many genera and 

 species yet in existence. The question arises : Can this assemblage 

 be divided into two or more faunas? It would appear possible to 

 do so when we consider, on the one hand, the Port Kennedy col- 

 lection with its 80 per cent of extinct species, and the Hay Springs 

 collection with about 70 per cent extinct, and, on the other hand, the 

 Conard fissure collection with only 47 per cent of extinct species. 



The latter has been referred by Professor Osborn to his third, 

 or Ovibos-Rangifer zone, of which he says : " The third mammalian 

 fauna is apparently that of the final glacial advance and, perhaps, 

 of a cold dry loess period " (Age of Mammals, p. 440). Arguments 

 may be offered to support this assignment, but the high per cent 

 of extinct genera and species, among them horses and saber-tooth 

 cats, makes it more probable that it is to be referred to the Illinoian 

 stage, whose ice-sheet approached much nearer the locality than 

 did the Wisconsin sheet. The absence of edentates and proboscid- 

 ians probably means nothing in this respect, for both were repre- 

 sented after the Wisconsin. 



If the contents of the Conard fissure are rightly assigned to the 

 Illinoian stage, the number of extinct forms at the onset of the Wis- 

 consin stage must have been far less than 47 per cent a conclusion 

 that seems to be reasonable. It would then appear to be possible 

 to divide the pre-Wisconsin Pleistocene mammals into two faunas, 

 an earlier and a later ; but when the attempt is made it is not found 

 to be so easy, and, if done at all, can be done only provisionally. 



When we consider the rarity of horse remains that have been 

 found in deposits overlying Kansan, lowan, and Illinoian drifts, 



