194 The American Geologist. September, 1904 
Three Hyolithes are described of which two are referred to species 
described of the Lower Cambrian of America. 
Though they are minute, considerable variety is found in the spe- 
cies referred to the Lamellibranchiata, as may be seen by the generic 
names Posidonomya (?) Modiolopsis, Synek, Davidia (3 species) and 
Ctenodonta. 
The Brachiopoda are rather meagerly represented by Obolla (2 
species) Acrothele Lingulepis (2 species) and Lingulella (3 species) 
Six plates containing numerous photographic figures of the fossils 
serve to give completeness to the memoir. These have the merit of 
accuracy and eliminate the personal equation, but for such small figures 
as those of the brachiopods and lamellibranchs they do not present 
determinate characters. Such a picture illuminates the fossil only from 
one side and fails to- bring out all the details. An enlarged drawing 
by the author representing what he saw in the fossil, viewed from 
different points, would help to fix the descriptions in the reader's mind. 
M. Delgado is to be congratulated on the complete manner in 
which he has worked up this fauna contained in a little bed of the 
Cambrian rocks of Portugal, and thus given a fixed horizon from 
which to determine the age of the connected formations above and 
below it. G. F. M. 
North America. By Israel Cook Russell. Pages x, 435; with 8 col- 
ored maps and 39 other illustrations. New York, D. Appleton & 
Company, 1904. 
This excellent compendium of geographic, climatic, biologic, geologic, 
and ethnologic description of our North American continent '^t- one in 
a series of convenient octavo volumes treating of "The Regions of the 
World." For this task the author has given in previous works full 
guarantees of his ability, having published, besides many and volumin- 
ous reports of the United States Geological Survey, several geographic 
works during the years 1895 to 1898, on the lakes, glaciers, volcanoes^ 
and rivers of North America. 
Professor Russell says in the preface : "While writing this book I 
have become more and more impressed with the incompleteness and 
inadequacy of the printed records relating to the geography of the con- 
tinent of which it treats. Extensive tracts, particularly in the f?r North, 
have not been traversed by observant men, vast areas throughout the 
continent have not been surveyed and mapped, and even in the some- 
what thickly inhabited portions of the more enlightened countries there 
are large districts in reference to the geography of which there is but 
little critical information available. Under these conditions it seemed 
best to select typical examples, of various geographical features from 
the better known portions of the continent to represent the conditions 
throughout the less thoroughly explored domain in which they ?re sit- 
uated, and at the same time serve to illustrate the highly creditable ad- 
vances made by .American geographers in definitely fcrmulatmg the 
principles of physiography. The book may, in a measure, be considered- 
as an atlenipt to present in popular form a report of progress concern- 
