on 8 
REVIEW OF GEOLOGICAL STRUCTURE. 21 
were quite different from what they are along the northern line of out- 
crop.* 
But any description of the Waverly group, as it appears on the Western 
Reserve, would be very incomplete and inaccurate that did not specify 
and define the marked subdivisions which it shows, and it has greatly 
facilitated both the communication and the acquisition of a knowledge 
of the formation to give to these subdivisions distinct names. The cus- 
tom of attaching local names to well marked subdivisions of geological 
formations, has been followed since men began to write on geology, and 
it will unquestionably continue to be followed as long as geological sur- 
veys and explorations shall be made. Beyond the region where the local 
subdivisions of a formation are distinguishable, the local classification 
will not hoid, but in the district where the Berea grit is well defined, 
and where, as on the Reserve, it is literally a mine of wealth to the cit- 
izens—furnishing building stones, grindstones, etc., to.the amount of a 
million of dollars annually—it is a matter of great practical consequence 
that it should be carefully described and its place in the series be accu- 
rately defined. To do this, it was indispensable that it should receive a 
distinct name. 
5. The Cuyahoga shale, stated in the above paragraph to be identical 
with the umbral of Rogers, and to reach in Pennsylvania a thickness of 
8,000 feet, is simply one of the local subdivisions of the Waverly in 
northern Ohio, and is not recognized in the central and southern parts 
of the State. Its identification with the umbral of Rogers, is not sup- 
ported by any satisfactory evidence. 
6. The Berea grit is supposed, by Professor Lesley, to ake into two 
parts in passing into Pennsylvania, the upper one to become the “ Ves- 
pertine” or “ First Mountain Sand,” the lower to descend and form the 
Chemung Conglomerate at Chautauqua Lake and Olean, New York. It 
is scarcely necessary to say that this view is entirely untenable. The 
_* On page 97, note, Professor Lesley says: ‘‘Dr. Newberry, in his Report of Progress. - 
of the Ohio Survey, for 1870, page 59, divides it (the Waverly) into three members— 
upper, middle, and lower—the Middle Waverly being a Conglomerate. This is the Be- 
rea grit and the New York ‘Conglomerate ;’ our Venango Second Mountain sand. But 
in the report of 1873, the Ohio geologists divide the Waverly group into four formations 
—Cuyahoga, Berea, Bedford, and Cleveland.” This paragraph contains three errora> 
which require correction. (1) It was Professor Andrews who divided the Waverly into 
three members in southern Ohio, Dr. Newberry into four in northern Ohio; (2) there is 
no evidence that the Middle Conglomerate of Fairfield county is identical with the 
Berea, and it is quite certain that neither are the equivalents of the ‘Conglomerate’ of 
New York, for they are Waverly and that is Chemung ;-and (3) the ‘‘New York Con. 
glomerate” is not the equivalent of the ‘‘Second Mountain sand” of Pennsylvania. 
