216 PALEOZOIC FISHES OF NORTH AMERICA. 
Sir William Dawson has described in his Acadian Geology a number 
of Carboniferous fishes, of which those of the Albert mine and Horton Bluff 
have been already noticed; most of the others are from the Coal Measures.' 
New species of Ctenoptychius, Diplodus, Rhizodus, Conchodus, Psammodus, and 
Gyracanthus ave described. Of these, Conchodus is apparently the palate 
tooth of a Dipterine Ganoid, probably belonging to the genus Ctenodus, and 
the Gyracanthus (G. duplicatus, Daw.) is one of the most peculiar and inter- 
esting species of the genus. 
In addition to the literature of the Carboniferous fishes already cited I 
would refer the reader to the following papers: 
Descriptions of the Remains of Fishes from the Carboniferous Lime- 
stone of Illinois and Missouri; by Joseph Leidy, M. D., Trans. Am. Philos. 
Soc., vol. 11, p. 87. 
Descriptions of some Remains of Fishes from the Carboniferous and 
Devonian Formations of the United States; by Joseph Leidy, M. D., Jour. 
Acad. Nat. Sci. Phila., 2d series, vol. 3, 1855-1858, p. 159, Pls. XV, XVI, 
XVII. 
In the Second Biennial Report on the Geology of Alabama, 1858, p. 38, 
Prof. M. Tuomey notices the occurrence of spines and teeth of fishes in the 
Lower Carboniferous limestone of that State. He mentions teeth of Psam- 
modus and a spine of Ctenacanthus “closely allied to Ct. tenuistriatus, Ag ,” 
and gives rough wood-cuts of this and two species of Cladodus, which he 
names C. Newmani and C. magnificus. The former of these is too imperfect 
for identification, but the latter I have often recognized among the fish teeth 
obtained from the Lower Carboniferous limestone of Hlinois and Indiana; 
very large teeth, with a central cone one and a half inches long and rela- 
tively small lateral denticles. 
The fishes of the American Coal Measures have been so fully illus- 
trated in the geological reports of Illinois and Ohio that it seems unneces- 
sary to attempt a thorough review of them here, but notes on a few new or 
more remarkable forms will be found on the following pages. 
' They are referred to in Acadian Geology, 1868, p. 209, 
