220 REVIEWS 
priate introductory chapter on the nature of material suitable for 
Portland and natural cement. Considerable space is devoted to a 
description of kilns, intermittent, continuous, ring, and rotary, and 
their relative merits are fully discussed. In the thirty or more plants 
which are described in detail, the wet, the half-wet, and the dry pro- 
cesses are represented, and the criticisms of the authors in regard to 
the fitness of each process for the material used is, on the whole, judi- 
cious. If the writers were preparing a series of articles today, how- 
ever, they would probably include in their descriptions a larger per- 
centage of mills using hard material, and have occasion to lay more 
stress on the ball mill as a suitable device for grinding. The matter is 
presented in a practical way, with numerous diagrams and illustrations. 
The impression is given that the American cement industry compares 
favorably with that of Germany, and that both of these countries now 
outrank England, the first producer of Portland cement. The trade 
in general is beginning to realize this fact, and today American cement 
is not discounted by the foreign product. 
The volume is a useful one both for students of economic geology 
and technology, and for those otherwise interested in the manufacture 
and use of cements. Roos Wwe 
Adephagous and Clavicorn Coleoptera from the Tertiary Deposits of 
Florissant, Colo., etc., etc. By S. H. ScuppDER, Monograph 
XL, U.S. Geological Survey. 
PROFESSOR SCUDDER’S investigations upon the fossil insects of the 
Florissant basin are well known. In Monograph XXI of the United 
States Geological Survey the rhynchophorous Coleoptera of North 
America were fully treated, and the present monograph is a temporary 
completion of the descriptions of North American Tertiary beetles. 
The new material described is nearly all from the Florissant basin, and 
is confined almost exclusively to the Adephagous and Clavicorn fami- 
lies. In addition to the new material described, however, a complete 
systematic list of the known non-rynchophorous Tertiary Coleoptera of 
North America is given, with bibliographic references and notes on 
geographic and geologic distribution. A large amount of new mate- 
rial from various western localities still remains to be studied, which 
will doubtless add much to our knowledge of these Tertiary insects. 
SeaWwe 
