402 Scientific Intelligence. 
b 
white quartz and flesh-colored feldspar, mostly the former. Wherever 
the strata of this rock remained horizontal, or nearly so, I found it usu- 
and architectural forms, which gave them, in the distance, an appearance 
of being old ruins. From these, Monument Creek has since received its 
Underlying the Cretaceous conglomerate I found immense strata of a 
green argillaceous shale or marl, which in appearance closely resembles 
the greensand of New Jersey, as I have seen it this winter. This green 
marl I afterwards found to be very abundant. In the black shales and 
Ww 
ally, I found extensive deposits of fossil shells, mostly Baculites and Am- 
monites. On one occasion, in the year 1861, at a point on the Platte 
river sixteen miles above Denver, I uncovered, in a space not more than 
six feet in diameter, the shells of eighteen Baculites which had been 
crushed flat but retained all their beauty of outline and brilliancy of color. 
After being exposed for a few minutes they crumbled to fragments. The 
longest of these was about four feet in length; the smallest but a few 
soil. Encrinites and Asterias were often found in the upper deposits, a8 
hundred and fifty miles eastward from Denver we travelled day and night, 
v 
Indians had driven off the stock, killing drivers, messengers and stock 
tenders, This compelled slow travelling and frequent stoppages for our 
stock to rest. With my revolver cocked in my hand ready for an Indian 
