STRATIGRAPHY OF THE POTOMAC GROUP 491 
Another interesting section is found on the opposite side of 
Licking Run in Reynold’s ‘‘Spring Drain’? mine, where the 
basal member of the Patapsco formation consists of a ledge of 
Fic. 4. View of Timber Neck, Anne Arundel County, showing Arundel, Pata- 
psco, and Raritan formations. 
ferruginous conglomerate and is found lying unconformably 
upon the Arundel iron ore clays below. Innumerable sections 
of the Patapsco deposits are found in other mines and along 
the streams, railroads, and highways which cross this region. 
Fosstls.—The fossils which have been found in the Patapsco 
formation consist chiefly of plant remains. A few poorly pre- 
served molluscan shells have been observed but no study has 
yet been given to them. No dinosaurian remains have yet been 
with certainty detected. 
The plant remains consist mainly of ferns, cycads, conifers, 
monocotyledons and dicotyledons. The dicotyledonous forms 
are not uncommon and according to Professor Lester F. Ward 
