94 
The Waverly Group in Ohio—Herrick. 
thick covering the whole Arctic region and extending almost 
continuously down to low latitudes is an assumption doing 
violence to observed physical facts and to probability, that it is 
not required to account for the phenomena and in fact is con¬ 
tradictory to some of them. 
{Geological notes from the laboratory of Denison University.) 
IL 
NOTES UPON THE WAVERLY GROUP IN OHIO 
By C. L. Herrick. 
To all thoughtful persons any evidence bearing on the unity 
of geological history must have special interest. Every year 
adds fresh material to the already enormous mass of evidence 
attesting the correctness of the view that life has pursued a 
continuous though devious path from its humble origin in the 
dawn-period to the present. Though perhaps all competent 
geologists now assent to this view from a theoretical standpoint, 
as all biologists certainly do, nevertheless there are many stub¬ 
born groups of facts which even yet are difficult to bring into 
harmony with this general conclusion. It is easy to say in a 
sweeping way that each age or epoch presents us with a distinct 
advance in structure and type, but it is not yet possible in all 
or even many cases to indicate the intermediate steps by which 
the fauna of one epocli gradually passed into that of the im¬ 
mediately following geological horizon. For example, one 
need not be greatly at a loss to discover the general path of 
evolution during the time represented by the Sub-carboniferous 
limestones in the central basin, nor yet is his credulity taxed to 
believe that out of these faunse there sprang the wonderfully 
homogeneous assemblage everywhere characteristic of the Coal 
Measures. But in the eastern portion of the central basin, where 
the integrity of the series is apparently broken and the lime¬ 
stones are nearly absent, the problem is very much more com¬ 
plicated. Indeed, the bridge between the Devonian and Car¬ 
boniferous has proved all but a pons asinorum , and he must 
be bold who ventures over. Out of the shales and free-stones 
lying between well-marked Hamilton shale below and the 
