OF ^ORTH AMERICA. 
91 
Leaving the Upper Silurian, we find under the Devonian, a heterogeneous assemblage of rocks, as one 
or two citations will show. 
On page 29 , our author says , « very fossilifcrous sandstones form the first devonian beds in Penn- 
sylvania and New York; then comes a great extent of marl and clay, presenting in certain localities 
quite numerous fossils; and lastly, the whole is crowned by very deep red sandstone, especially at the 
Catskill mountains, N. Y., at the base of the Alleghany mountains. Pa., and at Gasp6, Lower Canada. » 
Our author here takes no notice of one of the most extensive limestone formations in the United 
States, which extends from the Ileldcrborg in New York to the Niagara river at Black Rock, and thence 
trough Canada West, and forms the higher part of Mackinac and the northern part of Michigan proper, 
or the lower peninsular of Michigan. The same limestone extends from northern Ohio to Tennessee; 
and though elsewhere noticed, it is here omitted in the description of the successive beds or formations 
which constitute the author’s Devonian System. 
On page 30, he says, ((Since Mr. Agassiz has recognized carboniferous fishes, and Goniatites in 
the black slate of Ohio , this group ought to be placed in the lower carboniferous of which it forms the 
base.* Our author has evidently some confused idea that the position of the shales and sandstones of 
Ohio had been a mooted question, and that it has been settled as above. The truth is that Prof. Agassiz 
has not recognized carboniferous fishes in the black slate of Ohio ; no fishes at all have been found in 
that slate, neither have any Goniatites been found in the black slate of Ohio; and those found in the 
black shale of Indiana were not recognized by Prof. Agassiz. (N.B. — <( As my veracity is here called in ques- 
«lion, 1 will only say that I was obliged to leave Boston for my exploration of the Rocky Mountains, before the se- 
(icond proof of the first sheet of my work tvas printed; Agassiz with his habitual kindness toward ime, offered to 
((take the manuscript, and attend to the proofs himself; and I gave it to him, at the same time telling him he was 
((perfectly at libertv to suppress, correct, or do anything bethought proper; and ho did alter the manuscript in several 
((places; but as he did not touch the sentence relating to the fishes in the Iltack Slate of Ohio, I can maintain that 
((.Agassiz has recognized Carboniferous fishes in the Black Slate of Ohio without .having my veracity suspected by 
((an anonymous writer. Salford, the State Geologist of Tennessee, is also of the same opinion, and regards the 
liBlack Slate of the Ohio valley as Lower Carboniferous; so that I am not alone in ray view of this question.)) 
— J. Afarcou.) 
We will cite another sentence following the last noted: ((The Island of Mackinac, the Ohio foils 
near Louisville , and Perry county , Tennessee , have become classic points for the American Devonian , 
on account of the great number of fossils which are found there, and their identity in species, for the 
most part, with those found in the Eifel, in the Ilartz mountains, and in Devonshire.)) 
Now' Mackinac is a locality o? Devonian limestone in part, and yielding verg few fossils. The falls 
of the Ohio consist of Silurian and Devonian rocks, each yielding a good number of species. In Perry- 
county nine-tenths of the fossils arc Silurian, and their identity with the Eifel species may or may not 
be true, to some extent. The only fossil cited by the author from Perry county, as for as we observe, 
is Ilypanthocrinus decorus, a decidedly Silurian fossil (see page 27, and figure). Our author cites Spi- 
rifer mucronatus , and applies the name to two figures, both copied from Reports of New A’ork, one of 
which is the true species, while the other is Spirifer macronotus, a widely distinct species, the former 
having a narrow- area and strong plications, the latter a wide area and numerous fine plications. He 
is equally unfortunate in his localities, citing New A’ork, Ohio, and Tennessee. We suspect that no other 
person has seen either of these from the two last named localities. 
Spirifer hcterocHtus, Def. pi. iii, fig. 7, 7a. — For this species our author has reduced in size two 
figures of Spirifer congestus, from Report ith , Geol. District of New York, which species differs so widely 
from Spirifer heteroclitus , that we cannot comprehend how ho could have made the mistake. To make 
the matter worse, he cites the following localities in the United States: (dt is very frequent at the Ohio 
fall, and at Charlestown Road, Indiana; in Ohio, New- York, Pennsy-lvania and Tennessee.)) Now the 
species figured is not Spirifer heteroclitus, it has not been found at either of the localities named except 
New York; the species found at the Ohio Fall and Charlestown Road is neither the species figured, nor 
