THE GEOLOGICAL HISTORY OF NEW YORK STATE 57 
, which extend from the Catskill mountains to western New 
York. 
Except for the comparatively thin Tully formation, the limestone 
is confined to the Lower Devonic and the lower part is not more 
than a few hundred feet thick. Thus the great bulk of Devonic 
~ rock lies above this limestone and consists of shales and sandstones 
piled layer upon layer. These latter rocks are clearly land-derived 
_ sediments which were washed into the Devonic sea by streams from 
the Taconics and also probably from land areas which are known 
to have existed to the north in Canada. 
The Devonic strata, from oldest to youngest, abound in the fossils 
of marine organisms, and some fossil land plants have also been 
found. Looked upon in a broad way, Devonic life was much like 
that of the Siluric, though certain fundamental differences are to 
be noted. Thus the Devonic furnishes the first really authentic evi- 
dence of the existence of land plants. Such plants as ferns, lyco- 
pods (club mosses), and equisetae (horse tails) grew to be large 
treelike forms and in considerable profusion. Remains of these 
have been found in the Devonic strata in New York. All of them 
belonged to the very simple, nonflowering plants and were closely 
related to the plants of the next succeeding Carbonic (coal) period. 
Among the fossil animals especially abundant in the Devonic rocks 
of the State are: sponges, corals, echinoderms (star fishes), brachi- 
opods, mollusks (including the bivalves, gastropods, and cephalo- 
pods), and arthropods (including trilobites and eurypterids). The 
graptolites became extinct during the early Devonic. One of the 
remarkable features of the life was the great abundance and variety 
of fishes, so that this period is commonly referred to as the “ Age 
of Fishes.” From the zoological standpoint all the fishes were of 
simple types, the true bony skeletons of modern fishes being entirely 
absent. Devonic fish remains in considerable numbers have been 
found in the State. 
Carbonic strata are only very sparingly represented in New York, 
there being a few small outlying masses in the southwestern portion 
of the State (Cattaraugus and Allegany counties). Immediately 
southward, in Pennsylvania, Carbonic strata are developed on a 
great scale so we can be certain that the Carbonic sea spread over 
the southern border of New York State. It is quite possible that 
this sea extended over most of southern New York, but positive 
evidence, due to absence of strata, is lacking. 
The Permic is the last great period of the Paleozoic era, but 
rocks of that age are nowhere present in New York State. 
