92 
GEOLOGY 
is it the Spirifer heteroclitus\ though not only it, but one other species of that vicinity, resembles the 
Sp. heteroclitus still more strongly than the one figured; and finally, we venture to say. that neither the 
species figured, nor either of those at the Ohio Fall or Charlestown Road, have been found in the other 
localities cited. 
As an offset to the above, Chonetes nana, which is abundant aird almost universal in rocks of this 
age, is cited as found only in the environs of Louisville. 
Our author commences his description of our carboniferous rocks by insisting upon the existence 
of «vast beds of gypsum and rock salt.* The former is true of a few localities; as to the latter, one 
well authenticated locality only, so far as appears, furnishes rock salt. 
It is very remarkable that our author should have repeated the same rocks and groups under car- 
boniferous, which have been decribod under Devonian, viz.: « The bituminous shale, (or black slate) 
and Waverly sandstone series, and the fine-grained sandstones of Ohio, Illinois Indiana, the black slate 
of Tennessee,)) etc. These names, it is true, are not used, since he has omitted reference to all the 
western states in his Synonyma of Devonian sedimentary rocks; but as will bo seen, he cannot extri- 
cate himself from this difficulty. On page 30, he thus describes the Devonian: « To the west it extends 
through the southern part of the state of New York, forms the whole contour of Lakes Erie and St. 
Clair,)) etc. Now the extension of those rocks occupying southern New York, and along the shore of 
Lake Erie, to form its « whole contour,)) comes thence into Ohio, not by any identification or paral- 
lelism, by lithological or fossil affinities, but by absolute continuity. Yet our author describes first his 
Devonian as forming the contour of Lake Erie, and afterwards represents the same beds, the bituminous 
shale and Waverly sandstones of Ohio, as carboniferous, — these very rocks themselves forming the 
southern contour of Lake Erie. 
W'e have thus run over the work to the 33d page, and hero leave it. One point only we will 
notice. The sandstone of Lake Superior is classed as the New Red, notwithstanding alt the labors of Lo- 
gan, Owen, Foster and Whitney, and others, who have agreed in considering it lower Silurian. 
Wo will say nothing of our author’s attempts to systematize our mountain chains, if me needed a 
parody on Elie de Beaumont and his systems of mountains , we have it here. 
Mr. Marcou laments the want of accurate topographical maps, and because he has not such guides, 
he does not lay down on his map any mountain chains, but has « written near the places occupied by 
the different chains of mountains, the names of those chains.)) For the same reason we suppose, or 
some other equally cogent, he has given no lines of States, but has written the names of the various sta- 
tes somewhere near the places occupied by them respectively. This allows the limits of the various ge- 
ological formations to bo laid down any where near the places they occupy, without giving the pupil or 
the critic the means of determining their accuracy icithin many miles, a device perhaps convenient for the 
author, but not so for the student. 
The map in its geology is little more than a reproduction of that published by Lyell in 1.845, and 
in many respects it is inferior to that. As we have remarked respecting the text, the sandstone of Lake 
Superior is represented as the New Red, or of the ago of that of the Connecticut, Now Jersey, etc. 
But besides this, he continues a belt of the same formation across from the head of Lake Superior, by 
the sources of Rod river to the head of the Coteau des Prairies. In that direction he again takes up the 
same formation in the Wind River chain of mountains. In both these instances , there is not the slightest 
authority for supposing such belts of sandstone formation, and particularly any of the ago of the New Red. 
Without the slightest reason or authority, and in the face of facts, he runs a belt of lower carboni- 
ferous from the coal field of Michigan to the northeastern part of the Illinois coal field, and another from 
the eastern side of the Illinois coal field to the northwestern side of the Alleghany coal field. The latter 
is a worse error than the former, for he positively traces it across a broad belt of Silurian rocks which 
are a prolongation of those to the north of Cincinnati, and which are clearly followed northeastward to 
the lake shore and the islands west of Sandusky. 
