crystal, are particularly attractive to the majority of visitors. The beauty of these gaily colored rocks is quite extensively utilized by the inhabitants of the southern and southeastern hills to supply the place of growing plants which are generally denied by the inconvenience of the water supply. The quartzite of the Hills is well crystallized and heavy. I have one beautiful specimen of the dark Indian red variety through which passes a narrow line of pale blue, and the yellow quartzite or jasper sometimes shows dendrite markings. Very great quantities of agates and jasper, mostly in small pieces, but unlimited variety, are to be seen in portions of the Bad Lands, south of the fork of the Cheyenne River, with an almost equal abundance of baculites and numerous other fossils. The wide expanse of deep ravines and sharp, barren ridges in the Bad Lands is a unique departure from the usual phases of natural scenery that inspire interest and wonder, but no great admiration, until one soon learns that the law of compensation has been strictly observed. The beauty of vegetation denied those desolate buttes and ridges is atoned for by a marvelous abundance of most wonderful crystals of aragonite, calcite, barite and satin spar; each to itself, or two or more combined in beautiful geodes or else arranged in great flat slabs crystallized on both sides of a thin sheet of lime. These slabs are composed of crystals of uniform size and of a pale green tint. But the geodes show some striking combinations of both crystals and colors with an exterior formed like box work, composed of a very heavy dark material said to be a mixture of barium, calcium and iron. The interior may be a bright green or lemon yellow, or perhaps the two in combination, while others yet may be either of these varieties with the addition of flat crystals of almost transparent satin spar. These crystals also occur in masses of the same box-like formation rising just so much above the surface of the barren ridge they occupy as to give it the appearance of a prairie dog town. One hill-top over which an abundance of detached crystals, of the palest water-green tint, has been spread, gave the impression of being covered with crushed ice. This transformation from a richly tropical to a marvelously barren region, was accomplished during the time when storms reigned over the Hills and ice ruled the country to the north and east. The long slender barite crystals of a bright golden brown color are especially beautiful but are generally seen in the specimen stores, as the deposit is confined to limited areas and the few persons familiar with the locations are not over anxious to introduce the general public.