FISHES OF THE CARBONIFEROUS SYSTEM. 121 
ous, and contain large numbers of the fossils which are found in the Carbon- 
iferous limestone, especially in the Keokuk division. West of the Cincinnati 
axis the Waverly formation is thin and searcely distinguishable. In Michi- 
gan it is the Marshall group of Winchell, and is thicker and coarser, showing 
that we are there nearer the source of supply of the materials composing it. 
In Kentucky, Ohio, and Michigan the Waverly strata contain a con- 
siderable number of fishes, and although much remains to be done in col- 
lecting and describing the fish fauna of this group, it has already yielded 
the following list of genera and species: 
ELASMOBRANCHS. 
Ctenacanthus formosus, Newb., Cuyahoga shale, Ohio. 
triangularis, Newb., Cuyahoga shaie, Pennsylvania. 
vetustus, Newb., Cleveland shale, Ohio. 
compressus, Newb., Cleveland shale, Ohio. 
Clarkii, Newb., Cleveland shale, Ohio. 
furcicarinatus, Newb., Berea shale, Kentucky. 
angustus, Newb., Berea grit, Ohio. 
cylindricus, Newb., Knob stones, Kentucky. 
Hoplonchus parvulus, Newb., Cleveland shale, Ohio. 
Asteroptychius elegans, Newhb., Berea grit, Michigan. 
Gyracanthus Alleni, Newb., Cuyahoga shale, Ohio. 
compressus, Newb., Cuyahoga shale, Ohio. 
inornatus, Newb., Cuyahoga shale, Ohio. 
Cladodus subulatus, Newb., Berea shale, Ohio. 
Pattersoni, Newb., Berea shale, Ohio. 
Romingeri, Newb., Berea grit, Michigan. 
Hertzeri, Newb., Bedford shale, Ohio. 
concinnus, Newb., Cleveland shale, Ohio. 
parvulus, Newb., Cleveland shale, Ohio. 
Kepleri, Newb., Cleveland shale, Ohio. 
Terrelli, Newb., Cleveland shale, Ohio. 
Fyleri, Newb., Cleveland shale, Ohio. 
tumidus, Newb., Cleveland shale, Ohio. 
Orodus elegantulus, Newh., Cleveland shale, Ohio. 
variabilis, Newb., Berea shale, Kentucky. 
ramosus, Ag., Berea grit, Michigan. 
Phabodus politus, Newb., Cleveland shale, Ohio. 
Polyrhizodus modestus, Newb., Cleveland shale, Ohio, 
Stethacanthus tumidus, Newh., Berea grit, Ohio. 
Helodus coniculus, Newb., Cuyahoga shale, Pennsylvania. 
Mazodus Kepleri, Newb., Berea shale, Ohio. 
Platyodus lineatus, Newb., Knob stones, Kentucky. 
GANOIDS. 
Gonatodus Brainerdi, Thomas, sp., Berea grit, Ohio. 
Ctenodus Wagneri, Newb., Cleveland shale, Ohio. 
Actinophorus Clarkii, Newb., Cleveland shale, Ohio. 
