Ill LECTURES ON EVOLUTION 87 



of my friend Professor Marsh, with whom I had 

 the opportunity recently of visiting the precise 

 locality in Massachusetts in which these tracks 

 occur. I am, therefore, able to give you my own 

 testimony, if needed, that the diagram accurately 

 represents what we saw. The valley of the Con- 

 necticut is classical ground for the geologist. It 

 contains great beds of sandstone, covering many 

 square miles, which have evidently formed a part 

 of an ancient sea-shore, or, it may be, lake-shore. 

 For a certain period of time after their deposition, 

 these beds have remained sufficiently soft -to 



FIG. 2. TRACKS OF BUONTOZOUM. 



receive the impressions of the feet of whatever 

 animals walked over them, and to preserve them 

 afterwards, in exactly the same way as such im- 

 pressions are at this hour preserved on the shores 

 of the Bay of Fundy and elsewhere. The dia- 

 gram represents the track of some gigantic 

 animal, which walked on its hind legs. You see 

 the series of marks made alternately by the right 

 and by the left foot ; so that, from one impression 

 to the other of the three-toed foot on the same 

 side, is one stride, and that stride, as we mea- 



