1883,] 231 [Claypole. 
ered material from these (Genesee) beds is quite white, whereas a fresh 
broken mass is nearly black. The shales of which Tam now writing do 
not manifest any so marked change of color, but retain much more firmly 
their original black tint. They are very smooth and free from sand, usually 
dark, but sometimes greenish. They may be distinguished somewhat 
roughly in the field from the overlying Chemung proper, by the former of 
these characters and especially by the absence of those even-bedded, thin, 
fine-grained, square-fracturing beds of sandstone which so distinctively 
mark the Chemung proper in this region. 
The beds below these Cardiola shales, that is the representatives of the 
tenesee of New York, are remarkably barren, and have thus far yielded 
me no fossils in Perry county. The lower beds of the Chemung proper 
have also proved unprofitable ground. But the 200 feet of shale to which 
T have assigned the above name, though by no means rich in fossils, have 
nevertheless yielded a few species which enable me with confidence to 
assign them their place as representatives of the Portage group of New 
York. Some of these are peculiar to these beds, and must therefore be 
considered ‘‘characteristic’’ for the district. Chief among them, and 
almost everywhere present where these beds are exposed, is the small but 
beautiful lamellibranch figured in the Geology of the Fourth District of 
New York, by Prof. Hall, under the name of Avicula speciosa, now Car- 
diola speciosa, This shell was confined in its range to the Portage group 
of New York at the time of publication of the Geology of the Fourth Dis- 
trict, but is reported in the later volume (vol. v. p. 1) to occur also in the 
Genesee. In Perry county this species occurs toward the top of the beds 
that lie between the summit of the Hamilton'and the base of the Chemung 
proper, and there is consequently little precipitancy in referring them to 
the Portage, a conclusion which is in full accord with the evidence fur- 
nished by stratig raphy. 
[have not yet succeeded in establishing any wide or general physical 
plane of demarkation at which the fossils given on the next page cease and 
the Chemung fauna proper begins. The beds are somewhat barren with 
the exceptions here noted, Buta very convenient local horizon is afford- 
ed by a heavy bed of sandstone which occurs about 200 feet above the 
top of the equivalent of the Genesee slate. 
This bed of sandstone does not crop out in many places, but I have 
found it on the north side of the Buffalo hills on the road running from 
the old Juniata Furnace, where it forms the bank of the stream, and is 
thicker and more solid than anywhere else. It is also exposed on the road 
from Bloomfield to Newport, about a mile from the latter town, 
Adopting this view we have, for Perry county, the following section in 
this part of the column : 
Feet, 
Chemung shale and sandstone .... 
Portage-Chemung sandstone......... ceceeveee 20 
Jarcdiola (Portage) shale eveicseei dees Be CHARS GH NROO 
