220 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
North of Bellevue where the fold disappears under a covering of lava 
it is still a normal anticline, but where what seems to be the same fold 
reappears at Kanarra it has been compressed to such an extent that it 
has been completely overturned and the strata lie in inverted order with 
arather steep dip to the northwest. As this fold has been cut at this 
point by both the old and the new Hurricane faults, only a small portion 
is now exposed. 
The trough lying east of this anticline is unimportant. It dies out 
completely south of Toquerville, while at Kanarra it is so far compressed 
that the two limbs touch each other. The most eastern anticline lies 
close to the line of the Hurricane fault. On the south it flattens out, 
although the eastern limb persists as an eastward dipping monocline at 
the base of which is the Hurricane fault (Dutton, c, p. 114). In the 
northern half of the region covered by our map it is a strong arch with 
a dip of from twenty to forty degrees. The ridge east of Bellevue is 
formed where it brings up a hard core of Aubrey limestone which has 
since been bisected longitudinally by the Hurricane fault. On the 
eastern side of this core all the overlying strata have been stripped off ; 
on the western side where the country has been dropped far down by 
the fault, the overlying strata are to a great extent preserved. 
In a preceding section certain passages from Dutton were quoted, in 
which he calls attention to the marked resemblance between the condi- 
tions of deposition in the Appalachian province of the east during Paleo- 
zoic times, and those in the Plateau province of the west during the 
Mesozoic. Especial attention was called to the close similarity of the 
eastern Carboniferous which immediately preceded the chief Appa- 
lachian folding, and the western Cretaceous which preceded the period 
of folding that we have been discussing. The similarity seems to be 
even greater than has been supposed, for in both places at the end of the 
period of deposition the border region close to the shore of the denuded 
old land was notably, though doubtless very slowly, elevated. Close to 
the shore, just where the deposits of the preceding ages had accumulated 
to the greatest thickness, the uplift was greatest. Here too flexing and 
folding were induced in lines parallel to the former sea margin, while 
the strata that lay farther out to sea were almost undisturbed, and 
now lie essentially horizontal, both in the Allegheny plateau on the one 
hand and in the plateaus of the Colorado on the other. It seems to be 
a well-established conclusion that in the Appalachians this folding was 
due to pressure exerted in a direction tangent to the earth’s crust and at 
right angles to the shore line. This acted in such a way that the upper 
