OLDER POTOMAC OF VIRGINIA AND MARYLAND. 481 



Creek." The locality is not more precisely given, but it is probably that 

 described in Monograph XV as "72d Milepost." The following plants 

 occur in that collection: . 



Baieropsis pluripartita Font 16 specimens. 



Sapindopsis brevifolia Font 5 specimens. 



Sapindopsis magnifolia Font 1 specimen. 



Sapindopsis variabilis Font 10 specimens. 



No new forms not described in Monograph XV as found at this 

 locality occur in the collection, and hence there is no reason for changing 

 the conclusion drawn in that work for the age of the formation. The 

 age was determined as Aquia Creek. 



FOSSIL PLAM'S FliOJI >EA1! THK ;■->!> JULEPOST. 



On May 4, 1892, Professor Ward discovered a new plant locality, a 

 short distance north of that of the 72d Milepost, at the end of the railroad 

 cutting and below the tracks, on the west side. On July 28, 1893, I 

 visited the place in company with Professor Ward and we made a col- 

 lection larger than that made by him. The clay containing the plants 

 shows its top in a drain below the level of the roadbed. It forms an 

 undisturbed lens in the partially indurated sands. This clay no doubt 

 represents a lens similar to that which was torn up to form the redepos- 

 ited clay particles at the 72d Milepost. No plants were found here which 

 had not previously been found in the same general region. The following 

 is the list of species found here: 



Aristolochisephyllum crassinerve Font 8 specimens. 



Baieropsis foliosa Font 3 specimens. 



Glyptostrobus (Taxodium) brookensis (Font.) Ward 1 specimen. 



Leptostrobus longifolius Font - - .. 1 specimen. 



Sapindopsis magnifolia Font . 1 specimen. 



Sphenolepidium Sternbergianum densif olium Font 1 specimen. 



Sphenolepidium virginicum Font 1 specimen. 



Aeistolochi^phyllum crassinerve Fontaine. 



PI. CIX, Fig. 1. 



1889. Aristolocliisep'hyUum crassinerve Font.: Potomac Flora (IMonogr. LI. S. Geol. 

 Surv., Vol. XV), p. 322, pi. clx, figs; 3, 3a, 4-6. 



The large coarse leaves of Aristolochia'phyllum crassinerve occur in 

 a considerable number of fragments. Some of them are larger and better 



MON xLvm — 05 31 



