404 Annals of the Carnegie Museum. 



to the views of the writer, would have imparted a darker hue to the 

 stratum. This supposed lake probably had a small geographical area, 

 and judging from the comparatively thin, light-colored stratum, a rel- 

 atively short duration in geological time. 



I referred to a hard sandstone stratum forming the floor of the 

 quarry. In this stratum are often found foot-bones and sometimes 

 fragments of limb-bones, which are almost unrecognizable on account 

 of their much worn condition. It is evident that the bones were sub- 

 ject to moving water. Bones of greater weight and those which have 

 broad surfaces are always quite jjerfect in this stratum, retaining all 

 their sharp angularities. It would seem that there are at least two 

 plausible explanations of these facts. 



( i) That there might have been a stream of water which gradually 

 carried the foot bones o{ Moropus and other animals down stream, 

 thus causing their worn condition. (2) That the supposed lake, re- 

 ferred to above, might have had coves along its borders, especially at 

 the mouth of streams. There might have been a large spring of water 

 at one of these particular recesses near the shore of the lake, which 

 was much resorted to by various animals during certain seasons of the 

 year. When the water of the lake rose as the result of swollen streams 

 and continuous rains, it might have reached this veritable bone-yard. 

 The bones, which were small and had angles offering less resistance to 

 the waves, might then have been washed back and forth by the action 

 of the water, while flat and heavier bones remained stationary. This 

 latter view is, I think, the more plausible, according to the evidence 

 at hand in the Agate Spring Fossil Quarry and its immediate neigh- 

 borhood. 



