ib; PALEOZOIC FISHES OF NORTH AMERICA. 
panion of his father, Mr. Jay Terrell, whose name is so frequently mentioned 
on these pages, in his fossil hunting expeditions, and shared in his enthusi- 
asm and success. 
CLADODUS TUMIDUS, n. sp. 
Plate XXVII, Figs. 8, 9. 
Teeth broad and low, transverse length one inch, height of central 
denticle half an inch, base half an inch wide from front to rear, slightly 
curved, ends rounded; crown carrying three denticles, the central one 
robust, much recurved, rounded and flattened above perhaps by wear, finely 
striated in front and rear; lateral cones relatively large, abruptly conical, 
strongly recurved, striated throughout, subacute. 
But a single tooth of this species has so far been found. It was obtained 
by Mr. Jay Terrell in the Cleveland shale at Sheffield, Ohio. Others will 
be needed before the species can be fully and satisfactorily defined, but it 
is evident at a glance that this is quite different from any of the species of 
Cladodus which have been found in the Cleveland shale and from all that 
have been described from other formations. Its marked characteristics are 
the shortness and strength of the cones and the fine striation which covers 
the entire surface of each. In the specimen before us the central cone has 
evidently been sonfewhat worn, and from its great curvature the wear has 
not produced a blunt point as in C. concinnus and C. Terrelli, which have 
straight cones, but has worn off the anterior portion of the summit obliquely, 
so as to leave a rounded but acute extremity. The characters which have 
been cited will serve to distinguish it from any others with which it is likely 
to be compared. The small number of the cones, their recurved form, 
tumid aspect, and finely striated surfaces, with the narrow curved base, will 
serve to identify it wherever found. 
Crenopus WAGNERI, 0. sp. 
Plate XXVII, Fig. 30. 
Inferior palatal teeth ovate in outline, three inches four lines long by 
two inches three lines wide; strongly arched, rising one inch three lines at 
highest point when resting on a level surface; crown traversed by seven 
strongly marked ridges, separated by furrows of similar triangular section. 
