52 
Transactions Texas Academy of Science. 
Cragin, F. W. 
Editorial 'Comment. 
Amer. Greologist, Yol. XI'II, pp. 185-189. Minneapolis, 
1894. 
That portion of the editorial relating to Texas paleontology is found 
on pp. 186-189. It consists mainly of a criticism of the determination of 
■certain species on exhibition by the U. S. geological survey. 
59. Cummings^ Uriah. 
Art. American Eock Cement. Min. Eesonrces of the U. S. 
1895. 'hTonmetallic Prodncts, except coal. 
Seventeenth iVnnnal Eeport of the U. S. Ceplogical Survey, 
part III (continned). 
(Eock Cement in Texas), p. 891. Washington, 1896. 
'In a table showing the “Product of Rock Cement in 1894 and 1895,” 
Texas is credited as follows:; 
1894. 
1895. 
State. 
Number 
of Works. 
Barrels. 
Value. 
Number 
of Works. 
Barrels. 
Value. 
Tfi-x-n.s... 
1 
13,000 
$ 18,000 
1 
10,000 
$ 17,000 
60. Cummins, Duncan H. 
Texas Gypsum Formation. 
Science, Yol. XX, Xo. 516, p. 353. Dec. 23, 1892. 
“The Texas beds extend over an area of upwards of six million acres. 
'Extending from the north line of the State, south to the line of the Texas 
and Pacific Railroad, the beds vary in thickness from that of a sheet of 
paper up to seventy-five feet. The east line of the deposit passes Sweet- 
water, on the line of the Texas -and Pacific Railroad in Nolan county. 
The west line passes about twenty miles east of the /Staked Plains. The 
greatest thickness of these beds is about nineteen hundred feet.” 
'Six forms of gypsum are described, viz. : selenite, rose, massive, radiated, 
fibrous, and alabaster. In addition there are gypseous marls and gyp- 
siferous sandstones in great abundance. 
61. Cummins, W. F. 
Mining Districts in El Paso County. 
Geol. and .Scientific Bulletin, Yol. I, Xo. 2. Houston, June, 
1888. 
“There are two principal mining districts in El Paso county, one of 
them known as the Quitman Mountain district, and the other as the 
Eiabolo district. The Quitman Mountain district is about eighty-five 
miles southeast of the city of El Paso, and is on the south side of the 
