OLDER POTOMAC OF VIRGINIA AND MARYLAND. 519 



FOSSIL PLANTS FROM TKKIU COTTA. 



[PI. LXXX, No. 120.] 



At Terra Cotta station, on the Metropolitan Branch of the Baltimore 

 and Ohio Railroad, near Washington, above the bridge over the railroad, 

 in disturbed clay over the basal Potomac sand, I collected on Juh' 23, 

 1893, an obscure plant impression that looks like the rhizome of some 

 Equisetum. It is probably E. virginicum Font. 



FOSSIL PLANTS FllOM IVY t'lTY. 



[PI. LXXX, No. 130.] 



On July 21, 1896, Mr. Arthur Bibbins made a small collection of 

 fossil plants from this locality, and two days later he and Professor 

 Ward obtained a few additional specimens from the same place. Both 

 collections are deposited in the National Museum. The locality is a 

 sandpit near an iron mine, adjacent to the northwest corner of the Ivy 

 City race coui'se. The plants occur in ferruginous crusts at the base 

 of the pit. They are found in a coarse sand cemented by iron oxide 

 into a sandstone, hence the preservation is very imperfect, on account 

 both of the comminuted condition of the plants and of the action of 

 the iron on them. The following species were found there: 



Cladophlebis sphenopteroides Font. ? 1 specimen. 



Pecopteris constricta Font 1 specimen. 



Sphenolepidium Kurrianum (Dunk.) Heei' ? 1 specimen. 



Thyrsopteris Meekiana Font. 1 1 specimen. 



Thyrsopteris nervosa Font 5 specimens. 



Thyrsopteris rarinervis Font. ? 5 specimens. 



Most of these fossils are too imperfect to permit a positive identifi- 

 cation. They are in the form of small bits that are generally macerated 

 by water action. This collection is not sufficient to prove the age of 

 the strata, but it strongly indicates that the}^ belong to the horizon of 

 the Rappahannock or Fredericksburg beds. 



FOSSIL PLANTS FROM LANGDON. 



[PI. LXXX, No. 131.] 



This locality was discovered by Mr. Arthur Bibbins, who, on June 

 10, 1896, made a considerable collection from it for the State Geological 

 Survey of Maryland. 



