1 1 8 Editorial Cor/ivnent. 
lowed by a long list of fossils, with descriptions, from Flint 
Ridge, and amply illustrated. An appendix consists of a sum- 
mary of the Carboniferous trilobites and the description of a 
species which is identified with Proetus niissouriensls of 
Shumard, but which the author of the paper has removed to 
the genus Phillipsia, and has re-named P. Shiimardi. Another 
appendix treats of the bryozoans of Flint Ridge and contains 
reprinted descriptions of the species hitherto found at that 
locality with several original ones by August Foerste. 
Next follows the second part of a monograph on the Clinton 
group of Ohio, with descriptions, reprinted and original, of the 
fossils thus far identified by the writer. ISIr. Foerste's contri- 
bution to the paliEontology of the state in this monograph bids 
fair to be of great value to those who desire to see some progress 
made in the study of Ohio fossils. 
In a different direction is the paper on the determination of 
the horizontal component of the Earth's magnetic force by L. 
E. iVkins. This is a repetition of the method in use in the 
University of Glasgow and makes no pretension to originality. 
Such work is however near enough to geology to be included 
in this notice. 
Part II contains an account of the investigations carried on 
by Prof. Herrick and two members of his class on the shores of 
lake Superior during the past summer (iSS6). They are 
chiefly lithological and give details of the examination of the 
azoic rocks in the neighbourhood of Michipicoten bay. This 
w^ork involves the preparation of numerous thin sections of the 
rocks in question and of the slides thus obtained many good 
figures are given. 
The rest of this part is made up of an additional contribution 
to the geology of Licking county and a third installment of Mr. 
Foerste's monograph on the Clinton group. 
Our limits do not permit a longer notice. It is only fair to 
say in conclusion that the volume is exceedingly creditable to 
its authors and that it will be well for the cause of true scientific 
education in Ohio when our colleges produce more of such work. 
True mental development comes from this and not from ever 
so thorough and tedious an acquisition of the results of the labors 
of others. 
