68 RIO GRANDE COAL FIELDS OF TEXAS. [bull. 164. 
Hitchcock's map is based on McGee's. 
1887.. White (C. A.) . On the age of the coal found in the region traversed by the 
Rio Grande: Am. Jour. Sci., 3d series, Vol. XXXIII, January, 1887, p. 18. 
After examining the coal in the vicinities of Eagle Pass and Santo 
Tomas, and after studying collections of fossils, White concluded that 
-the coal beds were of late Cretaceous age, i. e. , Laramie or Fox Hills. 
1887. Hill (R. T.). Topography and geology of the cross timbers and surrounding 
regions in northern Texas: Am. Jour. Sci., Vol. XXXIII, pp. 291-303. 
A preliminary map of The Salient Topographic Features of the 
State of Texas accompanies this article. 
1887. Hill (R. T.) . The Texas section of the American Cretaceous: Am. Jour. Sci., 
Vol. XXXIV, pp. 287-309. 
On page 290 a map is given which represents, according to then 
existing knowledge, the areal distribution of the various geologic 
formations in Texas east of the one hundredth meridian. The Balcones 
fault is described,- and its influence on the topography stated. On page 
291 it is stated that the Navarro beds of Texas and the Fox Hills beds 
of the Northwest meet in the Rio Grande region. On page 302 Hill 
states that he has good authority for asserting the occurrence of strata 
of the Washita division "westward to the Rio Grande, beyond Eagle 
Pass." 
1888. White (C. A.). On the relations of the Laramie group to the earlier and 
later formations: Am. Jour. Sci., Vol. XXXV, pp. 432-438. 
This article contains a brief account of a journey from Eagle Pass 
to Laredo. According to White, the coal-bearing beds at Eagle Pass 
represent the Fox Hills group of the western section and the Ripley 
group of the eastern section. The beds containing the Eagle Pass coal 
pass below the beds containing the Santo Tomas coal. The latter beds 
are considered of undoubted Laramie age. This so-called Laramie is 
immediately overlain, in the vicinity of Laredo, by beds containing 
Claiborne fossils. The upper part of the Laramie is considered of 
Eocene age. 
1888. Hill (K. T.). The Neozoic geology of southwestern Arkansas: Ann. Rept. 
Geol. Survey of Arkansas, 1888. 
On page 101 Hill mentions that the ' c Rocky Comfort " (Austin) chalk 
extends from Arkansas to Maverick County, Texas. On the same page 
it is stated that evidence is found that the Gulf and interior provinces 
of the Cretaceous unite in the region of Eagle Pass. It is also stated 
(p. 47) that the Rio Grande is an example of ' ' an old Quaternary 
valley, filled with sediments cut through by the more recent streams." 
1889. Owen (J.) . Report in First Report of Progress of the Texas Geological Sur- 
vey, pp. 69-74. 
Although Owen did not apply names to the different beds which he 
examined, he has given so clear descriptions of them that every bed 
from the Edwards limestone to the Eocene can be identified. He 
recognized the relative stratigraphic positions of the Eagle Pass and the 
