162 
Transactions Texas Academy oe Science. 
Hill, Robert T. 
extend from Denton 'to Del Rio, a distance of 500 miles, and to be -one of 
the most prolific artesian areas in tbe world, several hundred wells and 
numerous rivers 'which have their origin dn fault-springs like those at Del 
Rio and San Antonio showing no appreciable diminution of the supply 
which has its source in the Trinity sands at the base of the Comanche 
series. During the past tW'O months, from the wells at Pottsboro and 
Dallas, I have discovered that the Dakota sands are also the source of 
another valuable artesian area, which, though not so extensive as the 
Fort Worth-Waeo area, will prove of great economic value to Texas.” Pp. 
120 - 121 . 
231. 
JSTotes on tbe Geology of the Southwest. 
Amer. Geologist, .Vol. VII, pp. 254-255. 'Minneapolis, Apr., 
1891. 
Contents: Gold in the Indian Territory. The Mineral Resources of 
Texas. 
Attention is called to the “many valuable materials” in Texas worthy 
of economic development : chalk, marl, greensands, gypsum, coal, huilding 
stone, etc. 
While (the 'State is rich in the rarer minerals they have proved of little 
quanti:ty. This statement 'applies especially to Tin and Platinum. 
232. 
The Comanche Series of the Texas- Arkansas Region. 
Bulletin Amer. Geol. Soc., Vol. II, pp. 503-528. May, 1891. 
Contents: Introductory Statement. 'Definition of Terranes: Consti- 
tution of the 'Comanche Series — The Trinity, O'r Rasal Division, Separa- 
tion. The Trinity Sands, The Glen Rose Reds. — ^The Fredericksburg or 
Comanche Peak Division, General Gomposition, The Paluxy 'Sands, The 
Gryphaea Rock and Walnut Clays, The Comanche Peak Chalk, The 
Caprina Limestone. The Goodland Limestone. — 'The 'Washita or Indian 
Territory Division. General Aspect, The Kiamitia Clays 'or 'Sehloenbachia 
Reds, The Duck Creek Chalk, The Fort Worth Limestone, The Denison 
Reds. Variation in the Character of the Deposits. iSubsidenee recorded 
in the Coinaneh.e ‘Series. 'Stratigraphieal Value of Terranes., To'pO'graphic 
Expression of the Comanche Terranes. Age of the Comanche Series. 
This paper was discussed by C. A. White, C. D. Walcott, and Cooper 
Curtice. 
For Review, see Amer. Geol., Vol. VIII, p. 259. 
233. 
Holes 'on the Geology of the Southwest. 
Amer. Geologist, Vol. VII, pp. 366-370. Minneapoli'S, June, 
1891. 
Contents: Thickness of the Upper Cretaceous Marls. Foraminifera of 
the Texas Region. Recent Tndian Work-lShops of Central Texas. The 
