760 REVIEWS 
the Appalachian axis; (7) the eruptive rocks and hot springs accom- 
panying the faults and Tertiary border in Texas and Arkansas; (8) the 
great thickness (5000 to 10,000 feet) of the Cretaceous and post-Creta- 
ceous sediments in the depressed area. 
Among other important things, the author concludes that the 
Ouachita uplift is the structural equivalent of the Cincinnati-Nashville 
arch; that the Coal Measure drainage of the Illinois-Indiana-Kentucky 
area was into the Carboniferous mediterranean sea through the Arkansas 
valley; and that the drainage of the Arkansas and Texas Carbonifer- 
ous areas was reversed about the close of Jurassic times, when the 
orographic movements to the east submerged the Appalachians in 
Mississipi, Louisiana and Texas. 
The Palzeozoic sediments on the south side of the Ouachita uplift 
are coarser than on the north side, indicating that they came from the 
the south. The same change of sediments is seen in the Silurian 
novaculites of the Ouachita uplift. It is on this ground that the 
Ouachita uplift is made the equivalent of the Cincinnati arch. 
A. H. PURDUE. 
ARKANSAS STATE UNIVERSITY. 
Maryland Geological Survey, Vol. 1. Wm. BuLLock Criark, State 
Geologist. The Johns Hopkins Press, Baltimore, Md. 
Following the good example set by some of the recent state 
geological surveys, the survey of Maryland presents in its first published 
volume a summary of the geological work which has already been 
done within the state. This ground is covered in Parts II, III and IV 
of the present volume, each of which treats of the subject from a dif- 
ferent point of view. ‘The first gives a history of the various organi- 
zations which have carried on geological work within the state, and 
references to the work of individuals not immediately connected with 
organizations. The next presents a summary of existing knowledge 
concerning the geology of the state, unencumbered by references to 
the men who did the work, the dates at which their results became 
known, and the publications where they were set forth, references 
which, if present, would seriously interrupt the continuity of the 
sketch. In this sketch are incorporated some of the results of the 
reconnaissance work of Dr. Clark and his assistants since the organiza- 
