LORAIN COUNTY. 215 
given the name of Dinichthys Terrellt, the maxillaries terminate below 
in a sharp, knife-like edge, which plays upon a similar edge on the man. 
dible, and the whole dentition constitutes a cutting or slicing apparatus 
of great power. So far as at present known, all the bones of Dinichthys 
found at Sheffield belong to this species, while all those found at Dela- 
ware appertain to ). Hertzert. A fine spine of Ctenacanthus (Ct. vetustus) 
was also found at Sheffield by Mr. J. W. Hulbert, of Elyria; and this is 
described in Vol. I., Part IL., p. 326, pl. 35, fig. 8. Mr. Terrell obtained, in 
addition to the fossils mentioned, several bones of small and, as yet, un- 
described fishes, some cones, apparently belonging to Lepidodendron, and 
an undescribed species of Gonzatites, all from the Huron shale at Sheffield. 
Broad, flag-like impressions of plants are very common in the formation 
here as well as elsewhere. These are undoubtedly the remains of sea- 
weeds, and it is probable that the carbonaceous matter the shale contains 
was derived from this source. 
The succession of the rocks exposed in the central and northern por- 
tions of the county will be seen at a glance by reference to the section 
given below, which begins at the surface of the Berea grit, 15 feet below 
the Lake Shore Railroad at Elyria, and reaches to the lake level at the 
mouth of Black River. 
SECTION OF THE Rocks IN THE VALLEY OF BLAck RIVER. 
Pe encamonibs LOTCKMESSs ts... cscece sesh sess 40 to 70 feet. 
2, Red shale, PAR se cetesesceces vices 30 to 60 “ 
3. Gray shale, DUNE Ba ccmn ster Aen ated. kes TKO). 
4, aque limestone, thickness............... 5 to 8 inches. Bae tee 
Symealcarecousvsmalen, Pins Tiel atk ses IW ixorown, | 
6. Black bituminous shale, thickness ... 27 feet. 
(ep Grayeshales thickness .2....)..2c1-s->a-es linha } cevetand shale. 
8. Black shale, like No. 6, thickness..... a0) 
9. Gray shale, to Lake, es ec 49 “ Erie shale. 
A well bored for oil in the valley of Black River, at Elyria, and begun 
a few feet below the base of the Berea grit, is said, by a near resident and 
stockholder, to have been carried to the depth of 1,000 feet, “600 feet of 
which was in shale, the remainder in limestone and sandstone.” If this 
boring can be relied upon, the interval between the Berea grit and the 
Corniferous limestone is here only about 600 feet, while at Peninsula, in 
the valley of the Cuyahoga, wells beginning at the same horizon were 
bored to the depth of 1,000, and in one case 1,400 feet, and, as reported, 
‘all in shale ;” and at Cleveland a well, begun more than 200 feet below 
the Berea grit, was sunk 1,000 feet in gray and black shales without 
reaching the limestone. 
