t 
REPORT 
Of T. A. Conrad on the Palaeontological Department 
- of the Survey. 
In conformity with instructions from the Executive, I beg leave, as 
Palaeontologist, to submit the following 
REPORT. 
As in my opinion, it is of great importance, both in a scientific and 
practical point of view, to ascertain as early as possible the geological 
age of the rocks of New-York, and as this can be done in a satisfactory 
manner only by comparison of the organic remains with those of other 
countries, where the formations have been accurately classified, I have 
drawn up tables of the fossils principally with a view to show how 
many species are common to the rocks of Europe and America. Our 
works of reference are as yet, unfortunately, few, but when this diffi- 
culty is removed I confidently expect to be able to discover in our fossls 
nearly all the characteristic species of the Lower Transition or Silurean 
System of Europe. 
There are some geologists who wish to establish in every island and 
continent, a peculiar system of rocks, independent of other remote 
countries; but when we consider that in the earlier eras of our planet, 
the temperature was uniform and the seas comparatively very shallow; 
would we not expect to find all the organic remains of such periods to 
consist chiefly of one group of species over the whole globe, especially 
when we find the flora of the Carboniferous era to have been every 
where nearly the same? Are not rocks of the Oolitic group in South 
America, the Cretaceous, and even the Eocene of North America, mere 
extensions of European systems, deposited in seas of the same periods, 
and containing the same groups of shells? Deeper oceans, and greater 
variation of temperature have cast more uncertainty over the upper Ter- 
