North Atlantic Pleistocene Problon—Shattiick. 99 
the fact that good observers mig-ht see scores of sections of 
Jamesburg and Pensauken, the one over the other, without sus- 
pecting a subdivision unless attention was especially directed to 
the matter. Even then it is probable that nine sections out of 
ten, or perhaps forty-nine out of fifty, would fail to be con- 
vincing on lithological grounds. But the tenth section or the 
fiftieth is conclusive, and carries the other nine or forty-nine 
with it." 
The Jamesburg is poorly stratified and often contorted as if 
bv lateral pressure. The limits of the high-level Jamesburg 
are upwards of 214 feet, and the low-level Jamesburg are 45 
feet, the latter being deposited in rude terraces. The surface 
of the Jamesburg is pointed out as being frequently marked 
with low-ridges and saucer-like depressions. The low-level 
Jamesburg is considered in part at least younger than the high- 
level Jamesburg. 
In the report for 1895 professor Salisbury states that the 
Jamesburg formation is very difficult to distinguish, and its 
existence has been called in question in many places. In this 
connection he says : "It should perhaps be stated that the ex- 
istence of the Jamesburg has been called into question at many 
points. Lithologically it so closely resembles what might be 
produced from the weathering of the underlying beds, that at 
many points and over considerable areas, its existence could 
not be affirmed on the basis of facts there represented. P)Ut 
there are various points, on the other hand, and these widely 
distributed, where the Jamesburg formation is represented by 
a thin stratum, which could not by any possibility have been 
derived from the underlying formations, and the certain pres- 
ence of the Jamesburg in such places is sufficient to carry the 
doubtful areas so situated that they cannot have escaped the 
influence of the agencies which made the deposits about the 
interpretations of which there is no doulit." He also states 
that the low areas about the coast are probably low-level James- 
burg, and are equivalent to the low-level Columbia, and in part 
contemporaneous with the Trenton gravel. 
In the report for 1896 under the head of Post-Pensauken 
submergence, professor Salislnu-}' mentions the 40-foot ter- 
races, and also terraces as high as 200 feet on the Mt. Pleas- 
ant hills, as being .(]c]X)sitefl l)y streams which emptied into the 
