Devonian Era in the Ohio Basin. — Claypole. 95 
Recurring to the other topic — the date of the shales — we 
must maintain that the evidence on which Dr. Newberry was 
compelled to rely, and which induced him to refer the Cleve- 
land shale to the Carboniferous system, was of the slenderest 
and most uncertain nature. He says : * 
"Aside from the great fishes which are characteristic of the Cleve- 
land shale and which, being all new species, do not decide the ques- 
tion, we do not have a great array of evidence. In the excellent ex- 
posures at Bedford the only fossils found are the spines and teeth of 
three species of elasmobranchs, Hoplonchus, Orodus, and Polyrhizodus. 
These three genera are characteristic of the Carboniferous system and 
have never been found in the Devonian, but they are hardly decisive, 
being specifically new. The recent efforts of Messrs. Read and Cush- 
ing have been reasonably successful, as they have found four species of 
brachiopods, which were reported by professor Whitfield to be Lingida 
cuyakoga Hall, Liiigula in die Hall, and Discina newberryi Hall, all 
well known species of the Cuyahoga shale. 
"The evidence, then, that the Cleveland shale is the basal member 
of the Waverly and therefore a part of the Carboniferous system, 
though not overwhelming, may be considered satisfactory." 
In regard to the three fossils first named in the above ex- 
tract, we may remark that the Orodus was found in [Michigan! 
and can hardly be valuable evidence for Ohio. It was found 
in a sandstone. The Polyrhizodus figured is an Illinois speci- 
men! from the St. Louis limestone, no notice being taken in the 
monograph of the species figured in the Paleontology of Ohio 
and referred to the Cleveland shale, at Bedford, so that the 
little Ctenacantlius {Hoplonchus) parvulus, also from Bed- 
ford, alone remains to give uncertain testimony with the three 
brachiopods above cited ; and in view of the enduring specific 
life of many of the forms of these two genera, reliance on them 
to decide important questions of correlation is very far from 
safe. 
It seems to me that Dr. Newberry fails to assign full value 
to the important evidence of the fossil fishes. Specificallv dis- 
tinct as they are from those of any other formation, yet their 
generic and ordinal aspect must have due weight. While the 
species of the great placoderms in the Cleveland shale are total- 
ly unknown in the Devonian strata below, yet it is most signifi- 
cant that the genera themselves are absent from the Carhonif- 
* Op. cit., p. 128. 
t Op. cit.. p. 106. 
t Op. cit., p. 209. 
