a, : * os 
78 Geological Survey of the State of New York. 
when we consider the shen and confusion that have pre 
vailed concerning these formations, and the impediments that ex- 
isted to a proper understanding of them, not to partake of the 
enthusiasm of the palzontologist, as he approaches the eee 
of his labors, and the gratification he expresses that ‘the legisla- 
ture of New York has had the liberality to cause the organic re- 
mains of the various formations to be figured and described in 
the final report of the geologists. The plan contemplated in 
describing them, is that of a stratagraphical, or grouping of all 
the organic remains in a particular series of strata, referable to 
one geological epoch; and a student may, with the book be- 
fore him in the field, identify at once the rocks he desires to in- 
vestigate.” 
“'The series in New York is far more complete than that of 
Wales described by Murchison, the formations pre-eminently 
characterized by their organie contents being three times the 
number of those illustrated in the Silurian System.” 
The comparison of the two series _has resulted in identifying 
the “Trenton limestone” with the “Caradoc sandstone,” the 
Llandeilo flags not being represented here,—showing the impor- 
tance of organic remains, in the absence of lithological ‘resem 
blance. , 
The “Salmon river sandstones and shales,” possess a distinct 
and peculiar group of fossils, and are not represented in the Silu- 
rian System. The “ Niagara sandstone” contains fossil remains 
peculiar to it, and is characterized in New York, Pennsylvania 
and Virginia, by the splendid Fucoides Harlani. Although this is 
not found in Wales, “some of the fossils in the strata above ita 
characteristic of the upper parts of the Caradoc sandstone ;” and 
all these Mr. Conrad considers its equivalent. ‘“'The Wenlock 
shale is identical with the shales at Rochester, which abound in — 
the Asaphus limulurus of Green, (A. longicaudatus, Murch.)” 
“The Wenlock limestone imimnddintely succeeds the Wenlock 
shale in Wales, but the two formations are here separated 
the following rocks, each of considerable thickness, and with 
distinct fossil groups. 1. Lockport limestone. 2. Gypseous 
shales. 3. Water lime series. Over the latter we find a blue 
sub-crystalline limestone, and then a gray shaly limestone, which 
together appear to represent the Wenlock formation, both in fos- 
sils and mineral character.” 
