oo REVIEWS 
The volume bears no date on title-page, or elsewhere where a date is 
naturally looked for, though the date 1917 appears under the state 
printer’s name. Its publication appears to have been delayed, as so 
many other volumes have been in recent years. 
R.. Dass 
Petroleum and Natural Gas in Indiana. By W. M. Loeay, State 
Geologist. Fort Wayne: The Department of Conservation, 
Division of Geology, 1920. Pp. 279. 
Like the preceding, this volume appropriately discusses the general 
fundamental questions concerning the origin and accumulation of oil 
and gas, and methods of finding it (pp. 10-48). A summary of the 
stratigraphy of the state (pp. 50-62) is followed by reports on the 
several counties. A map showing the oil and gas areas of the state 
accompanies the report. 
R. Ds: 
The Sand and Gravel Resources of Missouri. By C. L. DAKE. 
Rolla: Missouri Bureau of Geology and Mines. Vol. XV, 
ad ser. (1918). Pp. xii+274, 17 plates. 
A useful volume, dealing not only with the geological phases of the 
subject, but with the industrial phases as well. It is not restricted to 
surface sands and gravels, but includes available materials of these 
types in formations from the Cambrian up. Incidentally the volume 
presents a brief, up-to-date summary of the stratigraphic succession of 
the state, which is welcome and useful. The volume should be of value 
to those engaged in most sorts of construction work, both now and in 
the future, as well as to geologists. 
Re Des: 
The Physical Features of Anne Arundel County. By Homer P. 
LirTLeE and OTHERS. Baltimore: Maryland Geological Sur- 
WN, UONGs Jeo), Baa, OS, ©. 
This county report covers the physiography, geology, mineral 
resources, soils, climate, magnetism, and forests. The county lies in 
the coastal plain, and formations older than the Cretaceous therefore 
are wanting. One of the striking features of the geology of the region 
is the large number of unconformities in the Coastal Plain series. There 
