10 The American Geologist. January, 1862" 
beds higher up in the section. Within sixty miles along the 
strike, this 350 feet has developed into a great series with well 
marked horizons in the lower part,* while the upper part has 
become flaggy with not a few massive beds. The succession now 
is, the thicknesses being estimated, 
1. Not fully exposed, containing much red sandstone 700’ 
2. Conglomerate 40’ 
3. Shales and sandstone 1,000’ 
4. Conglomerate 30! 
5. Shales and flags 1,500' 
But the No. 1 of the section contains gray beds in the lower 
portion, which, in some localities, have yielded Chemung mol- 
lusks at not less than 300 feet above the conglomerate, while on 
New river, Va., where the thickness is somewhat greater, Che- 
mung forms were seen at about 500 feet above the conglom- 
erate. But the reddish beds which prevail toward the top seem 
to be non-fossiliferous. The tint of these beds becomes more 
and more pronounced toward the northeast, until in Catawba 
mountain, somewhat more than twenty miles southwest of James 
river, they have the dismal red and greenish color, so character- 
istic of the series along the Potomac. And yet, in McAfee’s gap, 
only eight miles northward, Sprrifera disjuncta and some other 
Chemung forms occur very near the top of the series, within a 
few feet of the Vespertine ( Pocono) sandstone, 
The other parts of the section can be observed at many places; 
the upper conglomerate (No. 2) contains flat pebbles, which 
frequently show the longer axis vertical to the plane of bedding; 
No. 3 contains concretionary sandstones passing downward into 
shales, with brown, blue and red to deep red flags and flaggy 
sandstones. Chemung mollusks are especially abundant near the 
top. The lowest division consists of flags and shales, olive, gray, 
yellow, blue and drab, with but few fossils. 
This is the section to James river, somewhat more than 150 
miles from the Tennessee line. Details of measured sections 
made in recent years between the James and Potomac rivers, a 
distance of not far from 200 miles, have not been published; but 
we need not wait for detailed measurements in this interval. Ob- 
servations by the writer and by others at many localities 
have proved the section persistent; and the same succession 
*Stevenson, Amer, Phil. Soc. Proc. vol. XXIV, p. 81 seq. 
