FLORA OF OLDER POTOMAC FORMATION. 361 



He was then describing and drawing his Potomac plants, and as Dop- 

 tor Newberry was at the same time engaged on his Flora of the Amboy Clays, 

 it was thought desirable that we should all meet in consultation relative to 

 these floras. Accordingly, on March 27, 1886, both Doctor Newberry and 

 Professor Fontaine came to Washington, bringing numerous drawings 

 of critical forms, and met me in council at the National Museum. The 

 result was satisfactory, and there was no longer any doubt as to the much 

 later age of the northern than of the southern beds. 



Doctor Newberry had at the time under his charge at the Columbia 

 University a coUection of plants previously made l^y Mr. F. B. Meek at 

 Federal Hill, in Baltimore, and it was arranged to lend the same to Pro- 

 fessor Fontaine for determination, the results to be included in his forth- 

 coming monograph. They were sent to him, and after a preliminary 

 examination of them he wrote me under date of April 26, 1886, as follows: 



On examining the plants sent by Doctor Newberry I find that they are all of 

 species that ,1 already possessed, possibly one excepted, and which were collected by me 

 at Dutch Gap and Fredericksburg. There are some 7 or S species, and they leave no 

 doubt in my mind that the flora of the Baltimore clays is the same as that of the 

 Potomac formation in Virginia. They certainly are quite difl'erent from the plants 

 Doctor Newberry is studying from the Amboy clay of New Jersey. 



A second reconnaissance and to some extent a collecting trip, was 

 begun on June 8, 1886, the party consisting of Professor Fontaine, Dr. 

 F. H. Knowlton, and myself, the means of transport being a steam launch. 

 The object was to descend the Potomac River and visit all the important 

 beds yielding plant remains that had been discovered in its bluffs or near 

 the river, making collections at each point. It was further purposed to go 

 up the James River as far as the Dutch Gap Canal, and points above, where 

 Professor Fontaine had found promising localities, and to continue the 

 work in this region. The programme was substantially carried out, the 

 principal locahties visited being Fort Washington, White House Bluff, 

 Masons Neck, Quantico, and Aquia Creek, on the Potomac, and Trents 

 Reach, the Dutch Gap Canal, and localities above, on the James. The 

 extensive collections that were made were sent to the University of 

 Virginia to be incorporated in the earlier ones of Professor Fontaine and 

 worked up in his monograph, then far advanced. He spent the greater 

 part of August, however, in Washington in order to make use of the larger 

 facilities in the way of books and specimens in completing his work. 



