Devonian Era in the Ohio Basin. — Claypole. 317 
other collector entered the field in the person of Dr. William 
Clark, of Berea, who became impressed with the thought that 
similar fossils might exist in his own neighborhood in the black 
shale of the Rocky river. His results surpassed even those of 
previous workers. In addition to large numbers of the old 
forms, a new and equally gigantic Titanichthys and, later, the 
yet more ponderous Gorgonichthys were added to the fauna of 
the shale, while the immense mandible of Brontichthys has since 
completed the quaternion. Nor did the species remain single. 
Of both Dinichthys and Titanichthys several species are now 
known varying in size from the huge D. hcrtzeri, D. terelli, 
Titanichthys agassiai and T. clarki to minute forms which af- 
ford scarcely a mouthful to their colossal congeners. Trachos- 
teus and Actinophorus lengthened out the list and were fol- 
lowed a little later by a completely new fauna consisting of a 
magnificent series of selachian fossils, giving us a knowledge 
of the early forms of this group far surpassing all that was 
previously known, and rendering the Cleveland shale of north- 
ern Ohio the typical ground for elasmobranch history. 
For more minute details regarding this remarkable fauna 
the reader is referred to the tables of the vertebrate fauna of 
the Appalachian gulf and to the section containing descriptions 
of the species. The above general account will sufficiently in- 
dicate the marvelous revelations of the Cleveland shale and 
their value in filling a gap in the geological record of ichthyic 
life and evolution. 
IV. THE VERTEBRATE FAUNA OF EASTERN 
APPALACHIA. 
No such discoveries as the splendid series of fossil fish, 
brought to light, in Ohio, by the unwearied labors of Hertzer, 
Terrell, Fyler, Wheat, Kepler, Clark and others, can be re- 
ported from the east. There few relics of this class have at- 
tended persistent search during fifty years, especially in New 
York. An examination of the tables will fully display this pov- 
erty of the eastern fossil fauna in vertebrates. 
The Oriskany has yielded no fish remains and the Cornifer- 
ous, so rich in the west, is almost equally barren in the east. 
Machaer acanthus, with one or two species, represents probably 
the elasmobranch fauna of that time. A single tooth of Di- 
