OLDER POTOMAC OF VIRGINIA AND MARYLAND. 537 



These fossils alone would not suffice to fix the age of the rocks 

 3delding them, but do not oppose the assumption of the Arundel or 

 Rappahannock age of the material. 



FOSSIL PLAMS FROM CON'TEE. 



[PL LXXX, Nos. 95, 97.] 



Two specimens come from near Contee, which is the next station 

 northeast of Muirkirk, on the Baltimore and Ohio Railroad. The label 

 accompanying one of these reads: "Peterson's mine, near Contee, 

 Prince George Co., Md." (PL LXXX, No. 97), with no formation 

 named. The fossil is a clay cast of a small cone which probably belongs 

 to Athrotaxopsis expansa Font. It suggests that the age of the forma- 

 tion is Arundel, or, what is the same thing, Rappahannock. It is No. 

 8242 of the Maryland Geological Survey, collected by Mr. Bibbins in 1896. 



The other is a specimen of Cycadeospermum rotundatum Font., 

 credited on the label accompanying it to "Iron-ore clays, B. & O. R. R. 

 cut, Contee, Maryland" (PI. LXXX, No. 95). This species in the Vir- 

 ginia Lower Potomac" was found in only one specimen, in strata of 

 Rappahannock age. So far as its evidence goes, it indicates that the 

 clays yielding it belong to the Arundel. The label does not give date 

 or collector, but it is marked "M. G. S., 8779." 



FOSSIL PLAMS FBOM ARLINGTO\. 



[PL LXXX, No. 73.] 



This locality is half a mile north of the village of Arlington and a 

 mile and a half east of Jessup station on the Baltimore and Ohio Railroad, 

 on the high ground, nearly 300 feet above sea level, which forms the 

 divide l^etween the Patuxent and Patapsco drainages, through which 

 passes the somewhat famous Jessup Cut. Several large collections were 

 made by Mr. Bibbins from points only a short distance apart in this 

 general region (see p. 389). These collections contain more specimens 

 than were obtained from any other locality. They are, however, mostly 

 duplicates of a comparatively small number of species. As the species 

 show that the various localities belong to the same horizon, and as the 

 rock matter containing them indicates that they come from the same 



" Monograph XV, p. 271, pi. cxxxvi, fig. 12. 



