818 The American Naturalist. [September, 
and extending to about twelve feet upward from the rain water which 
had accumulated here, on the day I sawit. The clay was red or brown 
and rather poor and the layers looking like a heap of reddish paper 
with darker papers introduced every now and then. On the top of 
this was about two feet of red glacial gravel in the form of till and 
between the gravel and the clay was a pocket of yellow clay which evi- 
dently belonged to the glacial deposit which I have examined all over 
northern New Jersey and which forms the so-called Lacustrine, Sed- 
imentary or Sub Peat deposits of Diatomaces which occur from Nova 
Scotia to Pennsylvania on the Atlantic coast of the United States. This 
stratified clay is Triassic and I examined it with considerable interest 
for it was formed in shallow fresh water, and contained Diatomace:e, 
scarce it is true, but the first Diatomace geologically speaking that 
have been found anywhere on the globe if we except the Diatomacese 
of the Carboniferous Coal found by Count Castracane some years ago. 
But the coal in which he discovered Diatomacez is doubtfully carboni- 
ferous. Perhaps it may be Tertiary. The Diatomacex I found in the 
Triassic clay were Gomphonema acuminatum and Brebissonia lanceolata 
along with straight sponge spicules, The clay was Triassic beyond a doubt 
for it was under the glacial clay and glacial till. What it rested upon 
is doubtful, Triassic sandstone most likely, for Triassic sandstone 
covers this part of New Jersey and no other rock is seen. It is impor- 
tant to note the finding of Triassic Diatomaces at this time and per- 
haps they will be seen in quantity further on. The color of the 
Triassic sandstone due to red iron oxide is remarkable and deserves 
investigation. The same color is present in the Catskill sandstone and 
at first they could be classed as one, but of course the fossils are differ- 
ent, and are very scarce in the Triassic, and rather plenty in the Catskill. 
It can hardly come from the magnetite on the border of the sandstone, as 
I. C. Russell suggests, for that, although present in New Jersey, is not 
always present and cannot be the cause of the red color of the Catskill 
sandstone. Perhaps it is present as an iron silicate, for it is more 
difficult to dissolve by boiling in acids than simple iron oxide. 
RTHUR M. Epwarps, M. D. 
Do Glaciers Excavate ?—The recent critical examination of 
Alpine and other mountain valleys by Professor T. G. Bonney, con- 
firms the conclusion he reached in 1874, that these valleys appear to 
be much older than the ice age, and to have been but little modified 
_ during the period or maximum extension of the glaciers, Mr. Bonney 
asserts that the erosive power of glaciers is small—quite unequal to the 
