674 ROLLIN T. CHAM BERLIN 



carapaces of turtles, of one specimen still firmly holding together 

 and undoubtedly still capable of being swept along by a stream for 

 a considerable distance without being torn to pieces. But the 

 cumulative evidence of the cases presented suggested strongly 

 that various particular individuals, at least, were primary fossils 

 but little disturbed since entombment. 



On the whole, it seems to me that Dr. Sellards has strengthened 

 his view that at least an essential part of the fossils of the lower 

 creek deposit are primary to that deposit, and that the extinct 

 animals represented by these fossils were denizens of the region 

 as late as the formation of the lower creek deposit, Sellards' forma- 

 tion No. 2. This does not entirely dispose of the hypothesis that 

 some of them were washed in from the older deposits in the process 

 of stream-cutting and stream-filling, but it renders that possibility 

 less vital to the essential question — the time of man's appearance 

 in this region. At the same time, of course, it brings the time of 

 extinction of the fauna of the lower creek deposit down to a rela- 

 tively recent date. 



It, however, left the critical feature of the problem — the admix- 

 ture of extinct animals with human remains, pottery, and bone 

 implements of modern aspect — still crying for a satisfactory expla- 

 nation. The crux of the whole problem seemed to be thrown upon 

 the trustworthiness of the discrimination between the upper and 

 the lower creek deposits. Now these upper and lower deposits 

 altogether measure only about 6 feet in thickness on the average. 

 This is a pretty thin deposit to divide into two distinct ages when 

 the natural irregularity of such deposits is considered, and when the 

 composition of the earlier and the later deposits is so nearly the 

 same as it is in this case. The upper creek deposition reaches 

 down to the year 19 13, when the digging of the drainage canal put 

 an end to the activity of this portion of Van Valkenburg's Creek, 

 and thus the occurrence within it of pottery, bone implements, and 

 the remains of man is altogether what one might expect. But the 

 presence of these same relics in the lower creek deposit would tell 

 a different story. It therefore becomes imperative to note sharply 

 in just what portions of the creek filling the significant relics were 

 found. It is also equally important to determine critically in what 



