54 Review of the New York Geological Reports. 
detrital deposition, and that too for a long period, viz. whilst the 
deposition of the two Pentamerus limestones and interposed Del- 
thyris shaly limestone was going forward ; each of which forma- 
tions must have required an immense lapse of time, since each 
contains a peculiar assemblage of fossils. 
These are the most abundant organic remains of the Oriskany 
sandstone. 
3. Atrypa peculiaris, Conran. 
Vanuxem’s Report, p. 133. 
Fig. 1. Delthyris arenosa, Conrap. 2. Atrypa elongata, Conran. 
