10 EIGHTH ANNUAL REPORT OF 



irregular pyramids, and extending upwards to a heighth of from one to 

 two hundred feet. " Viewed in the distance, these rocky piles in their 

 endless succession assume the appearance of massive architectural 

 structures, with all the accessories. of buttresses, turrets, and tapering 

 spires." The portion of the surface thus excavated forms a valley of 

 ninety miles in length and thirty in breadth, which in its most depressed 

 portion is about three hundred feet below the surface of the surrounding 

 country. So thickly are the natural towers studded over the surface 

 of this extraordinary region, that the traveller threads his way through 

 deep confined passages, which resemble the narrow irregular streets 

 and lanes of some of the old towns of the continent of Europe. At the 

 foot of these columns, the remains of the ancient animals, which Jived 

 and breathed long before the advent of man upon the face of the earth, 

 are found in such abundance as to form of this tract an extensive 

 cemetery of vertebrated animals, rivaling, in the variety of its extinct 

 species, the celebrated beds of the Paris basin. 



This region having been brought to notice by a few fossil remains 

 procured through the agents of the American Fur Company, an appro- 

 priation of about $200 for its exploration was made by the Smithsonian 

 Institution to Mr. Thaddeus Culbertson, who was about to visit, on ac- 

 count of his health, the sources of the Missouri. The specimens of 

 fossil remains which were thus procured, together with a collection 

 subsequently presented to the institution by Capt. Stewart Van Vliet, 

 of the CJ. S. army, and several specimens kindly lent by Dr. Prout, of 

 Missouri, were referred to Dr. Leidy for examinat on. In addition to 

 these he had the use of a collection lent by Prof. O'Loghland, of Mis- 

 souri, specimens belonging to the Academy of Natural Sciences, Phila- 

 delphia, and a collection made by Dr. Evans, at the instigation of Dr. 

 D. Dale Owen, the whole embracing all the specimens which have 

 yet been brought to the east from the Bad Lands. The bones are com- 

 pletely petrified, and their cavities filled with silicious matter. They 

 are preserved in various degrees of integrity, some being beautifully 

 perfect and others broken and imperfect, the latter having been evidently 

 subjected to violence while imbedded in a soft mud. The animals 

 belong to the classes mammalia and chelonia, or turtles. With a single 

 exception, all the species of mammalia belong to the great order of un- 

 gulata or hoofed animals, of which there are seven species of four 

 genera, which belong to the ruminantia, or cud-chewing animals ; two 

 species of one genus belonging to the paradigitata ordinaria, or even- 

 toed animals ; one species of the solipedia, or solid-hoofed animals ; and 

 four species of three genera belonging to the imparidigitata ordinaria, 

 or uneven-toed animals. 



The first specimen described belonged to a peculiar genus of rumi- 

 nants which, among recent animals, is more nearly allied to the musk, 

 and was probably hornless. The next is of a remarkable genus of 

 ungulata, representing a type which occupies a position in the wide 

 physiological interval existing between recent ruminants and the anom- 

 alous fossil animal called the anoplolherium. Another genus is called 

 oreodon, and constitutes one of the links necessary to fill up the very 

 wide gap between existing ruminants and an exceedingly aberrant form 

 of the same family now extinct. Another organic relic is that of an 



