No. 161.] 
191 
their chief coloring matter. In some localities the shale and sand- 
stone are red. This, however, does not frequently occur; nor are 
they then of any great thickness, occurring usually towards the 
upper part of the hills, or the mass. 
The sandstone is most commonly fine grained; its particles often 
cemented by the shale, the two being much intermixed with each 
other. It is to this cause, from the disintegrating nature of the 
shale, that so much of the sandstones of these counties is of a 
perishable nature. In general the layera of sandstone range from 
an inch to about a foot in thickness. In some localities, from the 
exceeding smoothness of its surface, being of the proper thickness, 
hardness and of all desirable dimensions, it forms the finest flagging 
that has ever come under our notice in any country. In other lo- 
calities, the surfaces of the flag stones are covered with either co- 
ralline or fucoidal bodies; these, though they diminish their econo- 
mical value, are not the less prized by the naturalist. The shale 
in some localities assumes a slaty structure, sometimes of a blue 
colour; but with the same tendency to decomposition, which cha- 
racterizes the great mass. There are other localities, particularly 
in Chenango and Broome, where there is a layer of the massive 
variety, which exhibits a tendency, owing probably to carbonate 
of lime entering into its composition, to form concretions parallel 
with the layer in which they exist; and so frequently do they oc- 
cur, as to be in a measure characteristic of that mass, as determin- 
ed by the position which they hold, relatively to a pecular fossil. 
The concretions are of all sizes, from an inch to several yards in 
length, and of proportionate thickness. West of Buffalo, on the 
shore of Lake Erie, similar concretions exist, frequently appearing 
as septaria; some of which are of uncommon magnitude and regu- 
larity. The septaria seem to contain a greater portion of carbo- 
nate of lime than those of the counties just mentioned, having 
their fissures lined with that mineral, often coloured with bitumen 
and sometimes with carbonate of iron. In a few instances accom- 
panied by anhydrous gypsum, and also sulphate of strontian. 
Limestonej marl and tufa. In the whole line of the southern 
frontier counties, from the Delaware river to Lake Erie, we did 
not find or hear of a mass of limestone forming a part of the tran- 
sition class, at all suitable for burning. Layers of limestone fre- 
quently occur amongst the shales and sandstones; but rarely over 
six inches in thickness, but so intermixed with those materials, as 
