84 Reviews— Geological Survey of Ohio. 
The recent revision of the fossil Mammalia, the fossil Reptilia, 
and the Fishes—still in progress—will all materially affect the 
possibility of making a moderately complete catalogue of British 
fossils for some time longer, and then the new edition will have to 
be pushed forward in a briefer space of time through the press 
than has the present issue. 
For owing to the large army of specialists which has arisen within 
the last 25 years, the task of the scientific compiler who undertakes 
to codify the long lists of species under each and every separate 
biological heading, becomes more and more difficult as the years roll 
on, and the Diogenes in Science who expects to find a perfect 
Nomenclator had better return to his tub and hang up his lantern. 
Whilst, however, it cannot be overlooked that there are many 
literary defects as to words and references which have unfortunately 
remained uncorrected even in the list of errata and corrigenda at 
the end of the volume, we cannot ignore our great indebtedness to 
the author for the time and patience he has bestowed in bringing 
out the work under many trials and drawbacks only known to 
some few of his more intimate personal friends. 
As might be expected of a work published by the Oxford 
University Press, the general aspect of these complex and difficult 
pages with their numerous columns—in some cases as many as 
twenty on a single page—is excellent and deserves great praise. 
This labour of love which the author has now so happily com- 
pleted, as regards Part I., has extended over fully thirty years of 
Mr. Etheridge’s life, having been the work of his leisure hours and 
done quite apart from his official duties, indeed, having been carried 
on often into the hours which most men wisely set apart for 
“« Nature’s sweet restorer, balmy sleep.” 
We feel sure that every one will read with regret the author’s 
announcement at the end of his Preface that, although the Mesozoic 
and Cainozoic portions forming Part II. of his Catalogue are com- 
pleted in MS., his other occupations deter him from attempting the 
task of preparing the remainder for publication. It is to be earnestly 
hoped that with the assistance of friends this difficulty may yet 
be overcome. 
Of one thing we feel sure, namely, that this first instalment of a 
much-needed and long-delayed work will be heartily welcomed by 
all, and will find its place as a work of reference on the shelf of 
every scientific library. 
Il.—Report oF THe Geonocican Survey or Onto. Vol. VI. 
Economic Geology. Royal 8vo. pp. 831, with Maps and Figures. 
(Columbus, 1888.) 
HIS volume is mainly devoted to a history of the origin and 
mode of occurrence of the natural gas and petroleum present 
in the rock-series of the State of Ohio. About four years since a 
deep well-boring in Hancock County, in the north-western part of 
the State, revealed the existence of large accumulations of carbu- 
