LARAMIE PLAINS RED BEDS AND THEIR AGE. 421 
in No. 47 in the little time required to have accumulated eight 
hundred feet of gypsum and sandstone. I realize that this is 
based purely upon theory; but nevertheless it seems advisable 
at this time to offer this suggestion. If adopted, it will deprive 
the eastern Rocky Mountain region of the term ‘‘ Triassic,” and 
make the basal member of the Mesozoic the Jurassic. Further 
west, especially along the flanks of the Wasatch Mountains, 
there are undoubted Triassic beds. 
A second question to settle will be the position of these Red 
Beds in the Paleozoic. Already the limestones along the 
Laramie Mountains have been referred to the Upper Carbonif- 
erous by several geologists; but upon very slight palzontologi- 
cal evidence. None of the early investigators were able to find 
many fossiliferous bands. In recent years I have found quite a 
fauna in the limestones, and this resembles the Kansas and 
Nebraska fauna of the Permian. The fossiliferous bands are 
near the top of the formation, and there may be typical Coal- 
measure fossils below; but such have not been discovered, and 
I am inclined to believe that the limestones of the Laramie 
Mountains correspond very nearly with the Permian of the Mis- 
souri Valley. The Red Beds merge into the limestones or rest 
conformably upon them, and here we have conditions very simi- 
lar to those that have been recently discussed from southern 
Kansas and to the southward. From our present knowledge, it 
seems advisable to refer the Red Beds of the Laramie Plains to 
the Permian. This classification has been suggested to me before. 
Only a few years ago Dr. Williston, while making me a visit, 
hemanked: ji Wihye"domyouynot place the Ked) Bedsin) the 
Permian?” I stated ‘‘that we had never been able to discover 
any fossil remains to guide us in identifying them as Permian.” 
At the time he advanced the idea that the Red Beds in Wyom- 
ing were very much like the Red Beds of Kansas. 
Further evidence concerning the fossils may be looked for, 
and I believe that many more localities will be found where fos- 
sils have been preserved that will materially aid in the future 
work. The finding of vertebrate remains is also of importance. 
