[October, 
624 Analysis of Books. 
is no need to reproduce arguments which have been already 
used in dealing with the author’s former pamphlet, and which, 
though expressed without any discourtesy, drew from him not 
experimental proof, but merely an angry letter. The moment 
he can give in favour of his theories any better evidence than 
declarations of inconceivability, we shall not be slow to acknow- 
ledge his merits. 
Bulletin of the United States Geological Survey. Nos. 2 to 6. 
Washington : Government Printing-Office. 
The second number consists merely of “ gold and silver con- 
version tables,” showing the coining values of ounces of fine 
metal. 
No. 3 describes the fossil faunae of the Upper Devonian along 
the meridian of 76° 30' from Tompkins County, Pennsylvania, 
to Bradford County, New York, by H. S. Williams. The author 
makes some useful remarks on the study of fossil faunae. He 
sa y S : “ VVe find that in the present ocean the depth of water, 
the temperature, the degree of saltness, and the freedom from 
organic impurities, have all a marked influence upon the normal 
fauna of every part of the ocean. Further, we find that on the 
two sides of an ocean, on opposite coasts of a continent, and 
even along a continuous coast-line, in two regions separated by 
a few degrees of latitude, the faunae are characteristically dif- 
ferent ; and when these geographical areas are far separated, 
although under similar conditions otherwise, the faunae may 
contain scarcely a single species in common. The revelations 
made by deep-sea dredging are also very suggestive. They have 
shown us that, with all these differences in the upper faunas in 
the depths of the ocean, species may range from one quarter of 
the globe to the opposite quarter with scarcely a varietal modifi- 
cation, and when the physical conditions have been continuous 
geological ages are not too long for the perpetuation of species 
without important modification. The wonderful effedts produced 
by ocean currents upon the distribution of faunas is brought 
forcibly to our attention by the reports of our Fish Commission. 
Their investigations reveal the existence of an abundant fauna 
within a hundred miles of the New England coast, entirely dis- 
tinct from the fauna prevailing all along that part of the coast 
out to deep water ; and further, this unique fauna, which at the 
time of its discovery was composed of a large number of species 
and a great abundance of individuals, has now apparently left 
the region altogether. From this we learn that in a very small 
