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[[underline]] December 5. - Continued [[/underline]]
I have specimens labeled on the spot to substantiate each point. An equally careful study of the upper part of the bluff would doubtless show that there is no substantial difference.

The highest part of the bluff is near the upper end and a small ravine separates this from the cliff in which Prof. Fontaine made his collections. Below this ravine and just around the great exposure, some fifteen feet above the river and perhaps 30 yards back from it behind a growth of trees and bushes I discovered a large lens of chocolate colored clay shales of firm texture, closely resembling the Mt. Vernon plant bed. They are full of vegetable impressions, but these did not come out clearly at the points where we struck in. Still one good specimen of Populus was collected, and there were indications of other forms. The place was not found until it was time for us to leave and we only worked some 15 minutes, thus
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missing our electric car which compelled us to walk to Alexandria. More extended operations may reveal a rich source of fossil plants. The horizon seems to be about the same as that at Mt Vernon. Immediately above the original plant bed of Fontaine the Potomac abruptly disappears and does not again come into view. At the very base of that cliff above there is a stratum several feet thick of unmistakable greensand belonging to all appearances to the Pamunkey. It has a sharp inclination to the north and is underlain by fine and soft grey sand which descends to the beach. The relations of these deposits to the materials exposed in the cliff are obscured by vegeation. They appear to pass entirely under the [[strikethrough]] former [[/strikethrough]] latter, but this is directly opposed to the theory that they consist of Potomac in place. 
There is no evidence that this marine Tertiary has slipped down the cliff, there being nothing corresponding to it in the clearly exposed face.