PALEONTOLOGY OF NEW-YORK. 
The formations of this age, which have been identified in Canada as 
far to the northeast as Gaspe, have not yet furnished determinable forms 
of Crinoidese, though fragments of them are of common occurrence in the 
strata. In the present state of our knowledge, however, it is impossible 
to arrive at any general conclusions regarding the probable number and 
distribution of the Crinoidege and Cystidege of this period. 
■We have heretofore regarded the Niagara period in America, as the 
Wenlock period is in Great Britain, the most prolific in these forms of 
fossil remains; but we have more recently learned that a single locality 
of Lower Silurian limestones in Canada has furnished more species of 
Crinoidege and Cystidege than have heretofore been found in all Lower 
and Upper Silurian strata together. The known habits of these animals, 
and the very limited geographical range of most of the species, are 
sufficient to warn us against conclusions based upon the very partial 
explorations ^yet made in the strata of this period. 
The Oriskany sandstone, within the limits of the State of New-York, 
has not furnished any well-defined species of Crinoidege or Cystidege; 
but in tracing this rock to the southwest along the Appalachian chain, it 
'becomes developed in much greater degree than in New-York, and con¬ 
tains numerous species of fossils not known in this State. Among these 
are several species of crinoids, of genera similar to those of the limestones 
below; showing, by these fossils as well as by the Brachiopoda and 
Gasteropoda, the intimate zoological relations of the two groups of strata. 
Among the peculiar forms which mark both the limestones and the 
sandstone, the Edriocrinas is perhaps the most remarkable : a crinoid 
which is sessile in its young state, and firmly attached to other bodies 
by the base of its cup, but becomes free as it advances, and gradually 
loses all evidence of a cicatrix; the base becoming rounded and smooth, 
or, very rarely, preserving a depression or pit near the centre, which 
marks the original point of attachment. 
There is likewise another somewhat similar form with solid base, which 
preserves the marks of attachment of the column; but all the specimens, 
thus far discovered, have afforded no clue to the structure of the upper 
