174 The American Geologist. September, i904 
eral locality. Of the other seven, six represent species of 
northern range not found in the first bed. The other one 
represents a species found in all the beds. This bed consisting 
as it does mainly of fragments shows probably far less of its 
original faunal members than the other beds. From those 
which it does contain it probably represents a condition not 
unlike the present except that the southern species were not 
again established at that point. 
Whether the idea of transportation of the material is ques- 
tioned or not there remains the fact that there are represented 
by the contained fossils, four distinct stages. All four stages 
probably represent a period during freedom from the ice sheet 
somewhere between the earliest and latest advances. 
Two species, Area pexata and Ostrea virginica. were found 
by Merrill in a bed intermediate between Beds 2 and 3. The 
list as here given includes all the species and varieties reported 
from these beds, the names used, being as far as possible, ac- 
cording: to latest usage. 
LAKE OTERO, AN ANCIENT SALT LAKE BASIN 
IN SOUTH-EASTERN NEW MEXICO. 
By C. L. Hi-:kkick. Socorro, New Alexico. 
PLATE XI. 
To a mind endowed with some vnaginative powers one 
of the attractive features of geological study is the continu- 
ous series of panoramic portrayals of earth-building which it 
spreads before one — pictures which present the grand out- 
lines of continents and seas during ^^lie course of profound 
changes requiring ages for their completion. It is a very 
apathetic mind that is not stirred by the sheer immensity of 
many of the geological movements which are plainly evident 
in the configuration of mountain and plain, especially in the 
arid region where there has been little glossing over of the 
rude narrative. 
This sense of the immensity of geological manifestations 
is felt in any mountainous region in the Southwest equally 
from two points of view. The evidence of profound faulting 
and dislocation is so clear and convincing: as almost to over- 
