242 PROCEEDINGS OP THE ACADEMY OF 



gests the reference to it of specimens in which the "last upper 

 molar has two inner cones," though it is distinctly stated in the 

 above Report that " the last upper molar of Palaeosyops has but a 

 single lobe to the inner part of the crown." Upon the latter char- 

 acter Prof. Marshproposed the genus Limnohyus, which, under the 

 circumstances is untenable, but might with propriety be applied 

 to the animal with molars like those of Palaeosyops, except that 

 the last upper one has two inner cones to the crown. In this view, 

 a specimen in the collection, of a last upper molar tooth, which I 

 had ascribed to Palaeosyops humilis on account of its comparatively 

 small size, would belong to Limnohyus. 



Remarks on Chipped Stones from Wyoming. Prof. Leidy 

 further called attention to a multitude of chipped stones, which 

 he had collected about 10 miles northeast of Fort Bridger. He 

 observed that he had noticed in many places in the vicinity of 

 Fort Bridger, covering the plains and ravines at the base of the 

 foot hills of the Uintas, great quantities of sharply fractured stone 

 fragments. They are frequently mingled with the rounded peb- 

 bles of the drift from the Uintas, but in other places are thickly 

 strewn over the ground without being mingled with the drift. 

 Mai^ of the fragments are broken in such a manner that it is 

 difficult to be convinced that they are not of artificial origin. 

 Mingled with the more evident accidental flakes there occur great 

 numbers of stone implements of the rudest construction, such as 

 those exhibited on the table. A few are also found of the finest 

 finish. Between these and the stone spawls of accidental origin 

 there occurs such a gradation of form as to render it doubtful at 

 times when nature ceased her labor and where primitive man com- 

 menced with his. 



The materials of the splintered stones consist of jaspers, quart- 

 zites, some of the softer rocks of the tertiary strata, and less fre- 

 quently of black flint, identical in appearance with that of the Eng- 

 lish chalk. The latter material I nowhere found in position, but 

 have been informed by Prof. Hayden that it occurs in the cliffs of 

 Henry's Fork of Green River. 



The accidental flakes probably had their origin through the 

 agency of frosts, and from the concussion of stones descending 

 from the declivities. In experimenting on some weather-Avorn 

 slabs of jasper from the buttes of Dry Creek, I found that mode- 

 rate blows of a hammer would send off sharp spawls, l-eminding 

 one of the ancient Hint knives. 



The splintered stones appear greatly to differ in age; while some 

 appear perfectly fresh as if recently broken from the parent block, 

 others are dull and worn, and many so deeply altered by exposure 

 as to look very ancient. In some of the old looking specimens, 

 the jasper originally black or brown has become whitened to the 

 depth of half an inch or more. 



Prof. Leidy further remarked as follows : I may take this op- 



