1 LOKA Ul- OLDEK I'UTOMAC FORMATION. 361 



He was llioii (l('scfil)in,ti and drawing his Potomac plants, and as Doc- 

 tor Xowberry wasaltliesainetinieengagcd on his Flora of the Aniboy Clays, 

 it was thought desirable that w'C should all meet in consultation relative to 

 these floras. Accordingly, on March 27, ISSO, both Doctor XewbeiT>- and 

 Professor Fontaine came to Washington, bi'inging numerous drawings 

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

 result was satisfactory, and there was no longer any doul)t as to the nnich 

 later age of the northern than of the sovithern IxhIs. 



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

 University a c-oUection of plants previously made by 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. The>- 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 hy Doctor New hen y I find that tliey are all of 

 species that I already possessed, possibly one excepted, and wliieh were eolleeted by me 

 at Dntch Gap and Fredericksburg. There are some 7 or S species, and tliey leave no 

 doiil)t 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 different from the plants 

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



A second reconnaisstmce 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 oljject was to descend the Potomac River and visit all the important 

 beds yielding plant remains that had been discovered in its Ijlnffs 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 localities visited lieing 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. Thfe 

 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. 



