52 TRANSACTIONS OF THE [Nov. 14, 
Columbia Collage collection there is a Mastodon tooth from that 
of Westchester Co., just across the Harlem River, and a bone 
is mentioned in Cozzens, p. 75. In other hills there was some 
local stratification into clay and sand and gravel beds, and at the 
42d street reservoir hard pan was met with. In the Manhat- 
tanville depression the surface is quite level and is diligently 
tilled by the market gardeners. 
The following sections exhibit the sub-surface structure with 
considerable thoroughness, and cover the lower part of the city. 
They have been obtained from Mather’s Report, 4th Dist. N. Y. 
S. Geol. Surv., pp. 135 ff.; from a paper by I. H. Russell on the 
Geol. of Hudson Co., N. J., Annals, N. Y. Acad. Sci., vol. II., 
pp. 27 ff.; and by personal inquiry. The classification into 
alluvial, quaternary, and drift is that of Prof. Mather. It is 
largely arbitrary and not of general application, as a comparison 
of the sections will show. 
Ave. D and Tenth St. Madeearth, 6 feet; marsh mud, 10 feet 
(alluvial); quicksand, 12 feet; shore sand and gravel, 53 
feet (quaternary); hard pan, 6 feet; coarse gravel, 3 feet 
(drift); total, 90 feet to rock. 
Ave. D and Seventh St. 100 feet to rock. 
Ave. D and Fifth St. Made earth, 6 feet; marsh mud, 10 feet 
(alluv.); quicksand and gravel, 65 feet; gray clay, 15 feet 
(quat.); total to rock, 96 feet. 
Ave. D and Houston St. To rock, 96 feet. 
Lewis Ave. and Seventh St. ‘To rock, 93 feet. 
Lewis Ave. and Houston St. ‘To rock, 94 feet. 
Allen and Hester St. An old well, 40 feet; quicksand and 
gravel, 20 feet; clay, 2 feet (quat.); coarse graveland sand, 
5 feet (drift?); to rock, 67 feet. 
Foot of Jefferson St.  Diluvium, 10 feet; stratified sands, 
gravel, and clay, 40; total, 50. 
Rivington and Columbia Sts. Old well, 20 feet; quicksand, 10 
feet (alluv.); marsh mud and clay, 20 feet; gray clay, 10 
feet (quat.); total to rock, 60 feet. 
St. Francis Hospital, Fifth St. 100 feet to rock. 
All of these except the last three are located on an old salt 
meadow which was filled in, before or about 1840, with drift 
from the street cuttings inland, and soon became one of the most 
densely inhabited quarters of the island. This accounts for the 
made ground, followed by marsh mud and the drift proper. 
Broad St. Made ground, 4 feet; yellow clay, 6 feet; gravel and 
qtz. sand, 19 feet; gray clay, 10 feet; total, 39 feet to rock. 
Trinity Church, Diluvial gravel and sands, 26 feet to rock. 
Washington Market. Made earth, 10 feet; river mud, vegeta- 
