FISHES OF THE DEVONIAN AGE. 61 
cles are very common, and Mr. Hertzer has obtained from the top of the 
Corniferous at Delaware, Ohio, what seems to be the decomposed and 
shapeless body of a small Elasmobranch, covered with dermal tubercles, 
which when detached seemed simply enameled granules, but where in 
contact are arranged in rows and appear rhomboidal. In the Marcellus 
shale of New York Mr. C. E. Beecher has also found masses of similar 
tubercles associated with small furrowed spines which may have been borne 
by an Acanthodian, but perhaps by a Selachian.' 
The fragment of a spine called by Professor Clarke Pristacanthus vetustus 
is certainly very unlike anything we have elsewhere found in our Paleo- 
zoie strata, and resembles the spines obtained by Agassiz from the Jurassic 
rocks, and called by him Pristacanthus securis; but I would eall attention 
to the spine described by Giebel, figured by Kayser” and named Ctena- 
canthus abnormis. This spine has the shaft longitudinally striated, and on 
the posterior margin bears a flange set with a single row of large denticles. 
Hence it does not belong to the genus Ctenacanthus, in which the longitudi- 
nal ridges are always pectinated or tubercled and the posterior margin is 
flattened or furrowed and is set with two rows of denticles. Giebel’s spec- 
imen is also certainly distinct from Agassiz’s Pristacanthus, but if the flange 
were broken off and alone preserved it might be readily mistaken for it. 
Only a fragment of the posterior portion of the spine is shown in Professor 
Clarke’s specimen, and it is possible that this was attached to a shaft some- 
what like that of the spine obtained by Giebel from the Devonian rocks of 
Germany. In any ease the spine described by Professor Clarke would seem 
to require a new generic name. 
The late Prof. F. H. Bradley collected from the Marcellus shale of 
New York a large number of the remains of fishes, principally detached 
teeth, which represent several new species, but they are impregnated with 
pyrites, are unsatisfactory subjects for study, and have not yet been de- 
scribed. They are in the cabinet of Yale College. 
1 From the Berea shale at Vanceburgh, Ky., I have patches of similar shagreen associated with the 
teeth of Orodus and Cladodus, and with the spines of Clenacanthus (Palwontology of Ohio, vol. 2, pl. 
59, fig. 4); also from the Berea grit, at Berea, Ohio, patches of rhomboidal dermal tubercles found in 
proximity with the spines of several species of Ctenacanthus. 
2 Die Fauna der iiltesten Devon-Ablagerungen des Harzes, Abhandl. geol. Specialkarte preuss., 
etc., Atlas, pl. 1, fig. 19. 
