132 The American Geologist. August, i892 
skulls — all horses. So far no Carnixora, but we shall get them. The 
aboence of rhiuoceros is so far peculiar, but we shall get them I suppose. 
We got none in the Blanco beds. This formation forms the entire sur- 
face of the Llano estucado aad is underlain by Trias and Permian. We 
found only the Loup Fork here, and how far it passes under the plains 
we have yet to know. Edw. D. Cope. 
Chtreadon, Texas, June 13, 1892. 
Dr. Wahnschaffe's Work on the Drift Deposits of Germany. — 
I was much interested in reading professor Salisbury's review of the 
"Drifts of the North German Lowland," in the May number of the 
American Geologist. It was gratifying to find one German geologist, 
at least, who seemed to favor the aqueous origin of kettle-holes. 
In 18S5 the writer published a small pamphlet on the drift formations 
of Long Island, in which the theory was advanced that the depressions 
connected with the terminal moraine were the result of sub-glacial 
streams. About this time, the late H. Carville Lewis had published a 
paper on "Marginal Karnes," and in it, he maintained that kettle-holes 
were not the result of natural erosion, and that they were in no way allied 
to ordinary valleys. I was confident, however, that future investigation 
would prove that he was in error, although I knew him to be a very close 
observer. It seems that their origin is still a disputed ([uestion. 
Professor Wright, in his recent work, the "Ice Age in North America," 
adopts the view that their formation was due to dirt bauds formed on the 
ice, although on page 54 he gives a picture of the Muir glacier where 
kettle-holes are in process of formation seemingly by the action of sub- 
glacial streams. 
I called his attention to this fact, and he admitted that in some cases 
kettle-holes owed their origin to sub-glacial streams. 
It seems from the review of Dr. WahnschaflEe's work referred to, that 
only one geologist — E. Geinitz — attributes them chiefly to the eddying 
action of waters during the melting of the ice. Dr. Wahnschaffe and 
others do not seem to favor this view, but insist that the waters arising 
from the melting of the last ice-sheet had no considerable infiuence in 
their formation. He argues that the depressions were already in exist- 
ence at the time of the deposition of the uppermost layer of till, which is 
doubtless true, but this need not weigh against their sub-glacial stream 
origin; as the channels may have been dried up, to some extent at least, 
before the final retreat of the glacier. The depressions in question are 
no chance formations but belong to a beautiful and wonderful system of 
glacial drainage. They are in reality sub-glacial valleys — the meeting 
place of the waters under the ice-sheet. Professor H. Carville Lewis 
argued that the rim of the basins was too perfect to admit of this, but 
when closely examined it will be found that the rim is generally 
more or less indented. The basin, of course, corresponds to the size of 
the streams that came together under the glacier. The small streams 
make the most perfect kettle-hole, while the larger rivers form the large 
ponds, swamps and peat-beds. I have studied this phenomenon for 
