ELISHA MITCHELL SCIENTIFIC SOCIETY 68 
River, at Hilton Park, one mile north of Wilmington. The 
river border at this point exhibits two terraces; one only a 
few feet above tide water, extending back a distance of 30 or 
more feet from the river; and the other rising 30 to 40 feet 
higher, extending back for a considerable distance, and in- 
deed representing the general surface of the region. The 
difference in elevation between these two terraces represents 
the thickness of the remnants of the Tertiary fossiliferous 
clays and limestone and the overlying recent sands. The 
lower terrace represents the upper surface of the Cretaceous ; 
_ so that the well starts in the Cretaceous clays and sands, and 
continues in them toa depth of some 1109 feet. In these sands 
and clays there are occasional beds of shell-rock and calcareous 
sandstone, varying in thickness from a few inches to 30 feet, 
and occasional thin beds of clay containing small nodules or 
concretions. The sands are mostly micaceous and are usually 
quite fine grained, with a prevailing gray color. From about 
700 to 800 feet, their color is decidedly greenish. Below 950 
feet these sands become coarser and are interbedded with oc- 
casional gravel deposits, but they continue fossiliferous to 
near the surface of the granite. 
Waterbearing sands and gravels were penetrated ata num- 
ber of points, notably at 380, 496, 520 and 574 feet; and at 
1011 the largest flow, of nearly 400 gallons per minute, was 
encountered, with pressure estimated as sufficient to raise the 
column of water 80 feet above the surface. Unfortunately 
the water from each of these levels was highly brackish, and 
hence unfit for domestic use. 
The fossil forms secured at different depths have been ident- 
ified by Dr. T. W. Stanton, of the United States Geological 
Survey. ‘The method used in sinking the well is the ordinary 
drill and sand pump; and, as might be expected, in some 
cases only fragments of shells were secured; but as the hole 
was of large diameter (12 inches near the surface, then 10 
inches, and lower still, 8 inches) and the larger part of the 
matrix material quite soft, a minimum amount of drilling was 
needed; and many large fragments and many perfect forms 
were obtained. 
7. 
