52 Review of the New York Geological Reports. 
Hall’s Report, p. 120. 
Fig. 1. Delthyris macropleura. 2. Atrypa levis. 3. Atrypa singularis. 4. 
4 liali ; 
We have not been able to identify these forms with any west- 
ern fossils which have as yet come under our notice. There is, 
therefore, neither palzeontological nor lithological evidence, at pre- 
sent, of the existence of equivalent beds in the Western States 
or Territories. 
Amongst the numerous beautiful fossils of the Catskill shaly 
limestone not yet published, there are several which Haut informs 
us are very analogous to the following forms figured on Pl. 13 of 
the Silurian Researches, and found in the Wenlock shale of Eng- 
land,— Orthis hybrida, O. canalis, Atrypa rotunda, A. linguife- 
ra, and several others. 
The following is a list of fossils of this formation which have 
tibed by Conran in the annual reports :—Acidaspis tu- 
