Page:Popular Science Monthly Volume 87.djvu/242

238 subject to occasional inundation when the advancing waters covered what had been land, while their retreat laid bare wide areas which had been submarine. The evidence of this was before our eyes, for as we went westward down the canyons, the sea shells would betray the marine origin of the strata, then as we climbed the slope beyond Buck creek we could see the older sea-borne sediments pass beneath the newer

Lance formation and become replaced by shales and sandstones of fresh-water origin. Occasionally one came across beds of lignite or woody coal which pointed to an abundance of vegetation, either forest or swamp lands wherein plants must have grown luxuriantly.

Out of this classic locality have come the remains of a host of creatures, the inhabitants of the shores of the old Cretaceous sea, many of which are now preserved in the Peabody Museum at Yale, the spoil of former expeditions. These are mostly dinosaurs, land-living reptiles