Pktkkson : Thk A(;ate Sprinc, Fossil Ouarry 



493 



gather with the prol)al)le way in which the bones may have been de- 

 posited. I have said that the stratum in which the fossils are found 

 in the c]uarry is of a h'ght color. In fact this layer is easily distin- 

 guished by its color from the under- and over-lying strata in this local- 

 ity. The stratum varies in thickness from a (ew feet to approximately 

 twenty feet, which is the maximum vertical depth. 1 have examined 



Fic; 5. Exposed poiiu in Niobrara N'alley one mile northwest of Agate Spring 

 Fossil Quarry. The light-colored stratum is approximately twenty feet thick. 



this particular layer in different j)laces, sometimes at one or two miles 

 distant from the quarry, and have nearly always foimd aljundant evi- 

 dence of laminated structiu'e. It would a))pear from the evidence at 

 hand that this light-colored stratinii is of lacustrine origin. The color 

 precludes the idea that there was hea\y vegetation, which, according 



