WARD. ] THE VIRGINIA AREA. 265 
fessor Fontaine, Mr. Charles 8. Prosser, and myself over the Triassic 
formation in Virginia. After visiting the Seneca sandstones, and 
tracing the approach of the Trias along the Monocacy River to the 
Potomac, we crossed the river at Point of Rocks and proceeded to 
Leesburg, skirting the western margin of the belt which consists 
entirely of conglomerates early called ‘“‘ Potomac marble,” but known 
locally only as ‘calico rock.” At Leesburg the trap appears not in 
the form of ridges as in New England and on the Hudson, but rather 
as a bowlder formation covering the surface; nevertheless, along 
Goose Creek it is heavily bedded and extensively quarried, there 
called ‘‘granite.” Near points of contact of the trap with the red 
shales these latter become lighter colored and in a few places some- 
what dark and carbonaceous. The nature of our expedition did not 
allow us time to search in these darker shales for fossil plants, but it 
is possible that such may occur and that future researches may reveal 
them. Several such localities were noted for this purpose. At Brents- 
ville heavy beds of sandstone of excellent quality for building pur- 
poses occur and promising quarries have been opened. Several of 
these were visited by us in company with Mr. J. L. Sprogle, the 
general manager, who offered us special facilities for examining them. 
In some respects this stone seems to excel that of the quarries in 
Maryland, but in all the Potomac beds the color is a more lively red 
than in the Connecticut Valley. A short distance east of Brentsville 
we found in lighter shale a fossil plant, Chetrolep’s Muensteri (Schenk) 
Schimp. We also found near Weaversville specimens of an Estheria 
and scales of fishes. Near the Rappahannock and Rapidan rivers and 
southward as far as Orange, notably at Culpeper, a marked difference 
occurs in the conglomerate from what we find at Point of Rocks and 
Leesburg, the material cemented in the sandstone consisting of bowl- 
ders of considerable size. We named this the Culpeper conglomerate. 
It is very similar to what may be seen in the Connecticut Valley and 
also in the vicinity of New Haven, being the same noted by Professor 
Dana on the east side of Pond Ridge. Professor Fontaine and myself 
found this conglomerate at a number of points in the Connecticut 
Valley. 
On this excursion we traced the Trias to Barboursville, where Pro- 
fessor Rogers supposed it to end, and where, in fact, it does disappear; 
but proceeding thence to Charlottesville we were surprised to find it 
in the valley of the Rivanna, only a short distance from that place, 
and a few miles north of Monticello. From Charlottesville we pro- 
ceeded to the coal field, striking it at Manakin or Dover Mines. We 
visited Carbon Hill and all the mires on the left bank of the James; 
crossed at Boscabell’s ferry and proceeded to Midlothian and Clover 
Hill, examining with minuteness the material thrown out at all the 
shafts in this region. The most promising places for fossil plants in 
