KEYIEWS. 
79 
The author has evidently compiled it with great care, and the determination 
of the species will he immensely facilitated by the elaborate tabular arrange- 
ments which serve as a guide to the genera. The whole of these tables are 
to a greater or less extent artificial in their character, but they profess to 
be nothing more, and in some of the larger and more complex groups this 
very artificiality has been taken advantage of to render the tables more 
direct guides to the desired end than they could have been if it had been 
attempted T to make them serve as an indication of the natural rela- 
tions of the forms. Thus, when the characters of the genera are subject 
to some slight variation, the characters of the aberrant species are worked 
out separately, so that the same generic name may occur two or three times 
in the same table, and by this means there is no doubt the species of the 
genus may be got at more readily. Under the head of fishes, of course, 
only the forms met with in fresh water are noticed, but the reader will be 
astonished at the immense number and variety of the animals of this class 
that find a home in the great lakes and rivers of the North American Con- 
tinent. The fishes, indeed, appear to be Dr. Jordan’s speciality, but it is to 
be regretted that he has thought it necessary to adopt so many genera. Of 
natural history, of course, there is very little in the book, which only pro- 
fesses to be a synopsis. The American geographical distirbution of the 
species is generally given, and in some cases where an animal is common to 
both sides of the Atlantic, its occurrence in Europe is noted, but very fre- 
quently this piece of information is omitted even in the case of species of 
the same genus. This is a defect which we hope may soon be amended in 
a second edition. 
AMERICAN GEOLOGICAL SURVEYS.* 
T HE energy and activity displayed by the Government geological sur- 
veyors in the United States are certainly worthy of all praise, and they 
are supplemented by a liberality on the part of both the central and local 
governments which contrasts rather strongly with what we are accustomed 
to nearer home. The important volumes on the 11 Cretaceous and Tertiary 
Eossil Vertebrataofthe Western Territories,” by Professors Leidyand Cope, 
and on the Cretaceous Flora of the same region, by Professor Leo 
Lesquereux, are now followed by a most admirable u Report on the Inverte- 
brate Cretaceous and Tertiary Fossils of the Upper Missouri Country,” which, 
while it cannot fail to interest the palaeontologist by the numerous excellent 
descriptions and figures of fossils, and the discussion of their generic and 
specific relations that it contains, must prove of almost equal importance to 
the geologist on account of the precise definition of the divisions and sub- 
divisions of the deposits from which the fossils described have been obtained 
and the light thrown on their relations to each other and to deposits in 
other parts of the world. 
The fossils here described are the result of the collections made by the 
* “ Report of the United States Geological Survey of the Territories,” 
vol. ix. u A Report on the Invertebrate Cretaceous and Tertiary Fossils of 
the Upper Missouri Country.” By F. B. Meek. Washington, 1876. 
