84 
Transactions Texas Academy of Science. 
Comstock^ Theo. B. 
Ores. [Rare Minerals and Precious 'Stones. iBuilding Materials. [Refrac- 
tory Materials. Materials for Paints. Miscellaneous Economic Products. 
Part dill. 'List of Minerals collected by the Survey from the Central 
Mineral District. 
‘The area included in the present review comprises a portion of what 
has been, not inaptly, termed the ‘Paleozoic 'Region of Central Texas.’ The 
general plan of the work of this division of the Oeological Survey has been 
to confine attention, in, most eases, to the rocks of the Pre-Carboniferous 
age, giving heed to the more recent strata only in so far as it semed neces- 
sary in order to present a clear and complete geologic history of the dis- 
trict. 
“u4s will be apparent from a cursory examination of the accompanying 
geologic map, the natural boundaries of this district are the escarpments 
of the Carboniferous and Cretaceous systems, the latter being by far the 
more extensive, and in some places completely obscuring the earlier rocks. 
- No serious attempt has been made to classify any of the divisions above 
the base of the Carboniferous system, although incidental notes are re- 
corded which may perhaps prove useful to students of the later sediments. 
As thus limited, the ‘Central Mineral Region’* (*“The title of ‘Central 
Mineral Region’ is adopted by Mr. E. T. Dumble, State (Geologist, to des- 
ignate this district as defined above; or, more properly, a restricted area 
within this field.” — 'Foot note, p. 239) comprises all of the counties of Llano 
and Mason, and large portions of the neighboring counties of Burnet, San 
Saba, McCulloch, Menard, Kimble, Gillespie and Blanco, with extensions 
into Lampasas and Concho counties. The area in square miles is about 
3,800, equivalent to more than three-fourths of the State of Connecticut, 
and nearly one-half of the area of New Jersey, and 500 square miles more 
than the combined superficies of Delaware and Rhode island, and yet 
forming less than .014 of the total area of the 'State of Texas.” P. 239. 
27. . 
Tlie Industrial Growtli of Texas. 
Tlie Age of Steel, Yol. LXIX, Xo. 1, pp. 19-22. St. Louis, 
Jan. 3, 1891. 
A popular article on Texas, in which, among other matter, reference 
is made to the mineral resources of the State. 
Tin in Texas. 
Eng. and Mining Jour., Yol. LI, pp. 117-118. Xew York, 
Jan. 24, 1891. 
An announcement of the facts concerning the discovery of tin iu Texas. 
The existence of tin ore in the State had been claimed for a number of 
years. There is no instance on record of what proved to be the discovery 
of more .than traces until the author’s announcement, in 1889, of the 
receipt of a small crystal of cassiterite from a resident of Llano county. 
'In November the author’s attention, in working up and determining min- 
erals, was called to some foi-mer collections made by the Geological Survey, 
and turned over to him for study, from Barrenger Hill, and from a local- 
