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heavy growth of trees, at a ptace where a creek had cut through 

 the stratum and partially exposed them to view. By digging in 

 horizontally many bones were obtained. The material in which 

 they were imbedded was exceedingly fine. With the exception 

 of a layer of about two inches in thickness it contained no rock 

 of a size larger than a buck-shot. He would ask Prof. Rogers 

 how it was possible that such a deposit could be formed in a state 

 of things requiring a violent transportation of such boulders as 

 lay above it. One would naturally suppose that the bones and 

 boulders and materials would be mixed together, if this view were 

 correct. On the other hand, he said, he saw evidence in the 

 ridges and other features of the country, of an upheaval subse- 

 quent to the deposition of the clay. The most recent deposit in 

 which mastodon remains had been found, was in Crawford Co., 

 where a perfect cranium had been discovered in an erosion of 

 the clay filled with fresh water marl. There were no shells 

 found with it, only leaves. 



Mr. Desor made some remarks in relation to a point to 

 which Prof. Rogers attached much importance as evidence 

 against the plausibility of Mr. Foster's and his own views, viz., 

 the want of marine remains in the deposite under discussion. 

 In a recent exploration of Tuckanuck shoal, near Nantucket, in 

 an area of twelve square miles, with a nearly uniform depth over 

 the whole surface, he had found, he said, not a single trace of shells 

 at a depth of about five fathoms. They could only be obtained 

 from the deep valleys intersecting the shoal, as explained at the 

 last meeting. On the coast of Texas, where similar flats exist, so 

 far as he had heard, the same barrenness prevails. Prof. Rogers 

 considered it strange, that in so wide a country as North Amer- 

 ica there were no traces of marine remains to prove the exist- 

 ence of such an extensive submergence ; for this submergence 

 must have been very extensive, as specimens of Tellina groen- 

 landica had been found near Montreal, at an elevation of five 

 hundred and forty feet above the present sea-level. If the water 

 stood at this height, there were very few points in the north-east- 

 ern and western part of the country which could have been above 

 the surface. That marine shells had not been found in the inte- 

 rior was no evidence that such would not be found. He would 

 remind Prof. Rogers that two years since it was thought there 



