DOCKUM BEDS. 189 



often highly impregnated with common salt, and none of them are free 

 from gypsum. The sandstones are red, gray, and spotted, and are generally 

 very friable. The gypsum beds are numerous and often very thick, and the 

 seams of fibrous gypsum traverse and transect the clays and shales in every 

 direction, ranging from paper-like seams to those ten inches in thickness, 

 and often making a perfect network of seams. Towards the western bound- 

 ary of these beds the strata are much distorted and folded. It looks as if 

 there had been a heavy lateral pressure from the west, crumpling the strata 

 into short folds. In the gypsum the folds are often only an inch or two 

 across. 



During the progress of this expedition, and since the publication of Dr. 

 White's article, I have found in the Clear Fork beds a few specimens of a 

 Productus. I have also taken a few new species from the different beds 

 which are yet to be described. 



The last of the Orthoceratites occur in the limestones of the Double Moun- 

 tain beds. In that bed the mesozoic types largely predominate. 



The vertebrate fossils described by Prof. E. D. Cope in his several articles 

 were taken entirely from the Wichita and Clear Fork beds, principally from 

 the former. The species described by him was each peculiar to the horizon 

 from which it was taken, except in a few instances. Out of about fifty 

 species taken from these beds and described by Prof. Cope, not a half dozen 

 come from both the Wichita and Clear Fork beds. This number may, how- 

 ever, be increased upon further observation. The fossil vertebrates found in 

 these beds embrace fishes, batrachians, and reptiles. Very few of them were 

 known to science until taken from these beds and described by Prof. Cope. 



The flora of these beds is yet undescribed, but enough is known of it to 

 see that some of the characteristic species of the Permian are contained 

 therein. It is intended to have the specimens of plant remains which have 

 been collected from these beds placed in the hands of a specialist for exami- 

 nation and identification. 



OVERLYING FORMATIONS. 



DOCKUM BEDS. 



A few miles before reaching Dockum, situated in the western edge of 

 Dickens County, I came upon a bed of conglomerate sandstone* and red clay, 

 resting unconformably upon the clays and sandstones of the upper Permian, 

 entirely unlike anything I have heretofore seen in Texas. This formation 

 lies along the foot of the Staked Plains in a narrow belt. Because of its ex- 

 tensive occurrence in the vicinity of Dockum, I gave the formation the name 

 of Dockum Beds, but will not for the present attempt to determine their cor- 



