966 The American Naturalist, — [Novena 
As yet no Bad Lands. At last, as we rode along, one of the 
party, who had been there before, told us not to look up until he 
spoke. Three minutes passed, and then the signal'came. We 
gazed on the most desolate spot I ever saw. For miles it was all 
the same. The names Bad Lands and its French equivalent, 
Mauvaises Terres, need no defense. Not a bit of green,—nothing 
but that creamy-white, calcareous, clayey rock; and this was 
not level and flat, but eroded into the most irregular surface one 
could imagine. Ridge and gully, ridge and gully succeeding 
each other for miles,—the summits of the ridge as sharp as the 
roof of a house, while the gullies in most instances were not wide 
enough to allow the passage of anything larger than a wheel- 
barrow. It was a magnificent chance to study erosion; but how 
was it eroded? The gullies were as dry as the crests of the 
ridges. Here and there we struck broader gullies, but even here 
soil was lacking and nothing green was to be seen. The light 
reflected from the creamy ground was very trying to the eyes, 
while the heat on a warm day was oppressive. Not a breeze 
finds its way into these narrow valleys. The walls sometimes rise 
at the angle of forty-five degrees; at others they are all but per- 
pendicular. They vary from fifty to one hundred and fifty feet in 
height. The strata of which they are composed are not homoge- 
neous. For the most part they can be easily cut with a knife; but 
here and there there are harder bands, and this alternation gives 
rise to strange erosion figures. The lower and softer strata wear 
away more rapidly than the upper and harder beds, and at one 
place the result was startlingly like a sitting man with a slouch 
hat. In places one finds vertical fissures filled with—now gyp- 
sum, now calcite. 
These Bad Lands are most celebrated for the fossils they con- 
tain. Inthe higher levels of the Buttes fossils are scarce. I am 
told that they yield but few turtles, and nothing else. In these 
lower strata of the Bad Lands mammalian remains are abundant, as 
well as turtles. Some of these latter are small, scarcely three 
inches in length ; some are veritable giants, the carapaces measur- 
ing nearly three feet by four. Turtle remains are very abundant. 
Some are as perfect as when the animal died, while others have 

