•i'.)i The American Geologist, Docombor. ww 
niic county; tin ore from Sand (reck: gold ores from Atlan- 
tic, Carbon; lead containing silver as argentiferous galena 
from the La Plata, as carbonate from Black Butte and Carbon 
county; and hematites from HartviUe, Johp Harper gulch, 
Rock Creek. Rawlins, and by an exhibiter from Cheyenne. 
The hematites from Carbon county, near Rawlins, are of fair 
appearance. A pyramid of iron ores is composed from four of 
the mines of the Wyoming Railway and [ron Co., in Lara- 
mie county. Hard and soft iron ores occurring in irreg- 
ular and lens-shaped masses in chlorite and micaceous schists 
are said to furnish an excellent Bessemer ore. There are also 
exhibits of petroleum from Fremont, Natrona, Cook, Johnson, 
Weston counties. Some copper ores, building stones, asbes- 
tos, fire clay, gypsum, sulphur, stream tin, marble and moss 
agates are also included in Wyoming's representation. 
T h i ; V x i r k i > States. 
There is a very well conceived and carefully executed column 
near the Pennsylvania exhibit giving the amounts of certain 
valuable products which are produced in the United States 
per second. At the base is a large block of bituminous coal 
on which rests a smaller cube of anthracite, supporting a 
cube of limestone, on which rests a cube showing the amount 
of natural gas in its equivalent of coal ; on this come petro- 
leum, iron ore. granite, salt, red sandstone for building 
(brownstone), and twenty-five cubes, ever diminishing up- 
wards, which represent the production of gold, silver, precious 
stones, etc. The design is a very good one and is well adapted 
to impart an idea of the enormous value of the mineral wealth 
of this country. 
REVIEW OF RECENT GEOLOGICAL 
LITERATURE. 
Development of the Brachial Supports in Dielasma and Zygosjrira. 
By Charles E. Beecher and Charles Schuchert. (Proc. Biological 
Soc, Washington, vol. viii, pp. 71-78, pi. x, 189.°).) 
The relation of the brachiopoda with spiral brachial supports to those 
in which these calcified supports take on the abbreviated form known 
as the loop, has been a fruitful subject of speculation, or, rather, of not 
over-shrewd guessing, by writers on these animals. 
