208 The Ainerlccm Geologist. October, \mz 
glaciers, gathered from a wide ami)hitheater to terminate l)elow 
in an apex in a narrow valley, we can see tliat there is room for a 
wide variety in the terminal deposits. 
The distinction ])etween the terminal moraine au<:l the true 
glacial boundary, was, as a matter of history, not so clearly in 
the minds of geologists when the task of tracing the terminal 
moraine acros > the continent was begun as it is now. Shortly 
after Mr. Upham had described the moraine as it exists on Long 
island, the official geologists of the New Jersey survey, profes- 
sors Cook and Smock, traced the moraine across that state from 
Perth Amboy to Belvidere. Their annual reports for 1877 and 
'78 contain the detail's of the location and structure of this mo- 
raine. Professors Lewis and (t. F. Wright then took up the 
work for the Pennsylvania survey; and their experience, especi- 
ally in western Pennsylvania, convinced them of the importance 
of giving attention to the extra-morainic glacial deposits. Al- 
though it was assumed, both in the New Jersey and the Pennsyl- 
vania reports, that the terminal moraine rested essentially upon 
the glacial boundary, yet professor Lewis, in closing the report 
upon Pennsylvania, stated that a study of the extra morainic de- 
posits would form the subject of a special report in the future. 
His untimely death, however, prevented him from completing the 
work. 
The boundary line was carried through Ohio, Kentucky, In- 
diana and Illinois b}- professor G. F. Wright, and it will be noticed, 
])oth in his reports and in his maps, that he distinctly aliandoned 
the purpose of tracing a continuous moraine, and pursued that of 
tracing the glacial boundary. 
This frequent non-coincidence of the glacial Ijoundary, and the 
.terminal moraine, is the key by which are to be explained many 
of the observations to which I am al)out to allude. 
During the present summer, 1 had the welcome opportunity of 
doing some field work in New Jersey, part of the time in com- 
pany with professor G. F. Wright, whose wide experience in 
glacial geology will give to our joint observations a value which 
thej' could not possess if made by myself alone. 
Attention has recently been drawn to the extra-morainic drift 
of New Jersey by professor Salisbury in two papers; the first being 
given at the Washington meeting of the Geological Society, one 
year ago; the second being pulilished in the last annual report of 
