46 Review of the New York Geological Reports. 
The only organic remains yet discovered in the group in ques- 
tion, are, the head of a trilobite, Hurypterus remipes, and the 
forms represented beneath. 
Hall’s Report, p. 137. 
a 
4 
& oe Wy Hi iN 
7 .\ ‘ 
Fig. 1. Cornulites,n.s. 2. Orthoceras leve, H. 3. Lozonema Boydii, H. 4. 
Euomphalus sulcatus, H. 5. Delthyris ——? 6. Atrypa ? 7, Avicula tri- 
quetra 
“These all occur at a single locality, and but one other shell 
has been seen in the group.” 
If any portion of the Onondaga salt group exists in the West, 
it is but obscurely marked. None of the above fossils have come 
under our notice in the Western States; but in the Du Buque 
district of Iowa, and on the opposite side of the Mississippi in Il- 
linois, on section fourteen, township twenty five north, range sev- 
en east of the fourth pritscipal meridian, a vermicular lime rock 
was discovered, answering to the description of the porous beds 
of the third division of the Onondaga salt group. If this has 
originated, as has been suggested, in crystallizations of muriate 
of soda, it cannot be considered much evidence in favor of the 
identity of the two formations; but the transverse septa and la- 
melliferous, cellular structure, visible in some specimens from the 
western formation, leaves little room to doubt their organic ori- 
gin. 
The country through which the Onondaga salt group extends, 
is usually marked by a series of low gravelly hills and clayey 
valleys, on which a stunted growth of timber prevails, known by 
the name of “ Oak openings.” 
Small portions of sulphate of strontia, galena and blende, 
with rhomb spar, occur in the upper portion of the group. Gyp- 
sum and salt are, however, the only minerals of economical val- 
