84 The American Geologist. Febmarr, 1899 
distinction between the Champlain epoch so-called and the 
Glacial epoch proper, so far as that is marked by the last till 
deposits. 
There are many deposits of the stratified group which are 
not yet fully understood. The first question which arises is. 
was a given deposit made inside or outside of the ice? The 
presence of distinctive ice-contact phenomena gives us the 
answer. The kame group still presents more difficulty than 
any other class of glacial deposits. The most general state- 
ment which can be given of the group is that kame topo- 
graphy indicates deposition of the materials in the presence 
of ice. Certain kames are. gravitatively rearranged, appar- 
ently superglacial extensions of the sand-plain group, others 
are similarly altered forms of lateral terraces, yet others are 
aborted eskers. But the stratified group as a whole now pre- 
sents an array of phenomena quite as explicable on the glacier 
hypothesis, to the exclusion of other known causes, as the 
first and once better understood till group. 
The ice-contact, which has furnished such important heh> 
in placing drift deposits, finds its expression in the classifica- 
tion in other terms, those which divide the deposits into cate- 
gories of drift laid down inside the ice or outside of it, or in 
general in those terms which express place relations to the 
ice. And since these place relations are everyw^here implied 
in the current classification of the phenomena of glacial de- 
posits, there can be nothing novel in a system in which the 
ice-contact is made one of the means of subdivision. The 
accompanying table has been drawn up with the ice-contact 
in mind. 
The introduction of a few little used terms demands an 
explanation if not an apology. Practically all forms of ice- 
laid drift may be spoken of as till, which has a wider meaninp 
than boulder-clay since some tills are sandy rather than clayey. 
A correlative term for the stratified drift, though much wanted, 
has not been brought into our language. The English geolo- 
gists have occasionally employed the term "kame group,'' 
but this has not found favor because it is misleading, particu- 
larly at the present day when the word kame has a more re- 
stricted meaning than formerly, if indeed it has a definite 
