216 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
p- 412), and in New Mexico dies out or is merged in the underlying 
Kanab formation (Dutton, ¢, p. 37, a, p. 152). Much further observa- 
tion is needed before we can arrive at a settled conclusion, but mean- 
while it seems to be a fair question whether the cross-bedded strata of 
the Kanab and Colob formations may not be continental deposits laid 
down by the wind. 
At the end of the Colob period the encroaching Cretaceous sea buried 
the desert, if desert it really was, and preserved a series of strata which 
to-day present some of the most magnificent scenery in the world. The 
upper Kanab canyon with its weird tracery, where the wind has brought 
into strong relief every line of the criss-cross lamin ; the Temples of 
the Virgin, where great snow-white domes, turrets, and buttresses rise 
thousands of feet above the valleys ; the gleaming rounded masses of the 
Colob plateau, standing in sharp contrast to the immense red precipices 
below them and the green wooded plateau and blue sky above, — all these 
and many other wonderful scenes we owe perhaps to a great dreary desert 
of long ago. 
Summary. In reviewing the physical history of the Plateau province 
from the Devonian to the end of the Eocene, as revealed in the strata 
of the Toquerville region, it appears that on the whole it was a time of 
slow and steady depression during which deposition was almost uninter- 
rupted. The surface of deposition stood close to sea-level all the time. 
There were two chief periods of quiet marine deposition, separated by a 
period of very uneven deposition. This latter was divided into two 
parts separated by a relatively brief interval of quiet deposition. The 
first period of uneven deposition was characterized by great variation in 
the texture of the materials deposited and in the manner of their deposi- 
tion, and by the preservation of terrestrial fossils. The second was 
characterized by remarkable uniformity in the texture of the materials 
and in the manner of their deposition. Arranged in tabular form, the 
chief periods are as follows: — 
1. The long interval between the Devonian and the end of the 
Moencopie was distinctly a marine era of even deposition, although 
the lower beds of the upper Aubrey are somewhat uneven. 
2. The period of uneven deposition lasts from the beginning of the 
Shinarump to the end of the Colob. It may be subdivided into three 
parts :— 
A. The Shinarump proper and the lower half of the Le Roux were a 
time of great diversity in deposition. Coarse gravels and marls were 
deposited side by side; lateral unconformities, fossil stream beds, and 
