Devonian Era in Ohio Basin. — Claypole. 351 
Pectoral fins with about 18 strong rays, two or three inches wide at 
the base, front edge about 6 to 7 inches behind the snout. 
Teeth with a single denticle on each side of the main cusp and about 
one-fourth of its height, main cusp striate. See Am. Geologist, 1893, 
p. 326. 
Cladodus fyleri Nby. 
This species was merely named and figured by Dr. Newberry with- 
out description and it is very doubtful if it can be identified with cer- 
tainty. No characters are given or ascertainable and the strong spine 
represented on the plate XLVi is almost certainly an error. 
Cladodus clarki Claypole. 
This is the best known species of the genus and a full description 
may be found in the American Geologist for Jan., 1895. The leading 
points are as follows : 
Length of fish about 45 inches. Breadth about 7 inches. Pectoral 
fins inches long by 4 to 5 in width at base, situated about 11 inches 
behind the snout. Rays about 18, strong. 
Teeth with a single median cusp and one denticle on each side of it 
about one-half of its length. Main cusp very lightly striate. 
Skin on lower side of neck transversely wrinkled. This is probably 
a generic character. 
Hinder portion of fish unrecognized. 
In the abdomen of the first specimen found lay a large coprolite 
showing a spiral line indicating the presence of an intestinal fold — the 
so-called spiral valve of the -hark. 
uladodus sinuatus Claypole. 
Nothing can be added to the short description given in the Am. 
Geologist for May, 1003. The fish was -mailer than .any of the preced- 
ing species, not exceeding ^o inches in length and the fin-rays are 
thinner. As the teeth are not yet known the reference to Cladodu 
provisional though almost certain. The species cannot yet be fully 
defined. 
Cladodus rivi-petrosi Claypole. 
The smallest known of the cladodont -harks of the shale, not ex- 
ceeding 24 inches in length. The teeth show two lateral denticle- on 
each side of the median cusp. At the least two different forms occur 
in the mouth of the single specimen known. 
Monoi ladodus, Claypole. 
Several specimen-, in Dr. Clark'- collection have been separated from 
Cladodus by the writer in consequence of the lack of the essential cla- 
dodont character — the denticles. The teeth, many of which have been 
exposed by the discoverer, show only the single median cusp which is 
long and of the usual cladodont form. To this genus are referred two 
of Dr. Clark's specie- as follow-: — 
MonclaHodus clarki Claypole — A fish about 63 inches long by 8 inches 
in greatest width between the pectoral fins. 
