490 MESOZOIC FLORAS OF UNITED STATES. 



It is somewhat remarkable that these should prove to be the only 

 specimens occurring in the later collections treated in this paper. None 

 were found at White House Bluff, where the original t^-pes were obtained 

 and where the plant was the most common conifer. 



FOSSIL PLAMS FROM THE MO^NT TEENOX BEDS. 



As intimated in the preceding account of the Aquia Creek plants of 

 White House and Mount Vernon bluffs, the horizon of the Mount Vernon 

 series of beds is below that of the Aquia Creek series. Prof. Lester F. 

 Ward, who discovered this horizon, has given an account of it and of 

 some of its plants in a paper entitled "The Potomac Foi^mation."" This 

 paper may be consulted for descriptions of the localities from which the 

 collections of plants were made and of certain of the plants. 



Collections were made from two localities on the Mount Vernon 

 horizon. One of these is the White House Bluff, while the locality first 

 discovered is higher up the river, above the mouth of Doag Creek. The 

 latter locality, for distinction, may be called "Ward's first locality," 

 while the other ma}^ be designated "Ward's second locality." The two 

 localities are on exactly the same horizon. It should be stated that the 

 first locality has ^delded much the larger variety and quantity of plants. 



The following is the histor_y of the collections from these localities: 



1. On October 16, 1S92, Prof. Lester F. Ward discovered the principal localitj^, 

 viz, that above the niouth of Doag Creek, on the Mount Vernon estate. The exact 

 spot is opposite the site of the old Fairfax mansion and directly under the high point 

 once known as Roses Delight.'' Only a small collection was made on that day. 



2. Professor Ward visited the locality on November 6, 1892, accompanied hj 

 Mr. Victor Louis Mason, prepared to make a much larger collection, in which they 

 were successful. 



.3. The party last mentioned discovered the Mount Vernon chocolate claj^s in 

 the White House Bluff on December 5, 1892. Only one specimen, however, was 

 collected on this occasion. 



4. On May, 14, 1893, Messrs. Ward, Mason, and Hunter made an excursion 

 to both of these localities and brought back a large collection. 



5. I accompanied Professor Ward to the original Mount Vernon locality on 

 July 25, 1893. It was then much altered, the overhanging clay beds having fallen 

 and buried it under talus. Only two specimens were obtained, as we had no facilities 

 for uncovering the bed. 



"Fifteenth Ann. Rept. U. S. Geol. Sure., 1895 (see pp. 324-325, 348-366, pi. ii-iv). 

 6 See Fifteenth Ann. Rep. U. S. Geol. Surv., 1895, p. 325. 



