Art. IX.] Herrick-Johnson, Geology of the Albuquerque Sheet. 221 
Series is lacking and the Dakota sandstone is deposited uncon- 
formably on the lower formations of the above classifications. 
The line between the Upper Coal Measures and the Permian or 
Permo-Carboniferous is arbitrarily drawn, and is based wholly 
on palaeontological evidence, the strata being conformable. 
Concerning the age of the Cimarron Series of Kansas much 
has been written. It has been referred in turn to Permian, 
Permo-Trias, Jura -Trias, Triassic, and even to Cretaceous. Prof. 
Cragin correlated the Kansas Cimarron Series with the Texas 
Permian, and Prof Prosser accepted this correlation, provision- 
ally. In a more recent paper Dr. Williston says, “That these 
red beds are not contemporaneous with the Texas Permian 
would seem assured, and I feel yet more confident that they 
are what they were first considered to be, of Triassic age.” 
Prof Grimsley regards the Red Beds as marking the transition 
from the Permian to the Cretaceous. Mr. Vaughan, of the U. 
S. Geological Survey, studying the Upper Palaeozoic and Creta- 
ceous of Oklahoma and Indian Territories and Southern Kansas, 
spoke of the Red Beds as Permo-Trias. In several localities 
fossils have recently been found in the Red Beds, and it may 
not be long before the question as to the age of this series will 
be definitely settled. 
Permian in Texas. 
The finest development of the Permian system of this 
country is found in Texas. As defined by Professor W. F. 
Cummins it includes “ all the Red Beds in Texas which lie be- 
tween the upper part of 'the Albany Beds of the Coal Measures 
and the Dockum Beds, or the lower part of the Triassic as rec- 
ognized here.” (In a more recent paper Prof Cummins states 
that the Albany Beds have proved to be but another phase of 
the Wichita Beds, or lower Permian. The dividing line be- 
tween the Permian and Coal Measures then becomes the contact 
of the Cisco division with the overlying Wichita — or Albany — 
Beds.) The rocks of the series in Texas are similar to those 
of the Kansas Permian, comprising limestones, sandstones, 
shales, red and blue clays, and gypsum beds. As in Kansas, 
