128 CONTRIBUTIONS TO DEVONIAN PALEONTOLOGY. [bull. 214. 
The limestone (No. 29 of the section) contains probably not more 
than 25 per cent of lime, but since no other bed in the section above 
the Chemung contains an appreciable quantity of lime, it is regarded 
as a limestone. It will be designated the Armenia limestone lentil; 
it occurs in the upper part of the Oswayo formation. 
The Armenia Mountain section lies about 14 miles southeast of the 
Tioga section and 10 miles northwest of the South Mountain section. 
The detailed Armenia section as given above may be safely assumed 
to represent closely the concealed upper part of the Tioga section. 
The Armenia limestone is easily recognizable in each of the three seel 
tions. The few fish remains occurring in this bed are of Carbon- 
iferous type. Below the Armenia limestone occasional plant remains 
are the only fossils seen until beds containing Catskill fishes are 
reached. The beds in which these fossils appear abundantly lie in the 
South Mountain section 797 feet below the horizon of the Armenia 
limestone and in the Armenia Mountain section 754 feet below the 
same horizon. 
As yet no invertebrate paleontological data are available for drawing 
any sharp line of distinction between the Devonian and Carboniferous 
sediments. In the absence of entirely adequate data for determining 
this boundary it is perhaps most convenient and practicable to conj 
sider the latest appearance oi Catskill fish remains as marking the end 
of the Devonian period. This horizon occurs in the section near the 
division line between the Cattaraugus and Oswayo of the Elkland- 
Tioga folio. 
In the few sections in this region showing nearly continuous expo- 
sures from the Chemung fauna to the Sharon conglomerate there is 
seen to be very slight basis for a division on the basis of color, the 
red beds being nearly as common in the upper as the lower portions. 
It will be noted, however, in examining average sections where the 
greater part is covered that red beds appear to be most abundant in 
the lower third of the section. This is largely due to the fact that the 
lower beds are very generally tough sandstones which are apt to out- 
crop prominently, while the upper red beds are nearly all soft shales 
which are likely to outcrop less conspicuously, if at all. This ten- 
dency of the upper red beds to be soft shales and the lower to be tough, 
flaggjr, and often cross-bedded sandstones is correlated with their 
faunal characteristics — the upper red and gray beds being, with the 
exception of the Armenia limestone, entirely barren of animal remains, 
while the lower contain numerous fish remains. 
The invertebrate fauna, from the lowest beds of the section to its 
termination upon the appearance of sediments of Catskill type, is dis- 
tinctly Chemung in character. 
Most of the sections in the region about Mansfield are characterized 
by one or more beds of iron ore. There appear to be three of these 
