res 
Claypole.} 502 [May 16, 1884, 
If, however, any should prefer to relegate it to a system of ‘‘passage- 
beds ’’ connecting the Onondaga and the Lower Helderberg, no valid ob- 
jection can be raised to the course pending the discovery of further and 
conclusive evidence. It will not affect the arrangement above proposed. 
I must remark in conclusion, that the suggestions now made are pro- 
visional, and therefore subject to change, according to future evidence. 
It does not seem probable, however, that the main outline of the plan will 
be altered. 
Note. Since this paper was written I have obtained an excellent speci- 
men of Pterygotus Osborni, Hall, from the massive limestone of Juniata 
county. This may be considered a proof of the identity of this limestone 
with the Water lime of New York. For this specimen I am indebted to 
Mr. Jas. Stevenson of this city (Akron, O.), a former resident of Juniata 
county, Pa, 
SUMMARY OF THE GROUPING DETAILED ABOVE. 
New York. Perry County, Pa. 
oe Upper Pentamerus limestone. 
% 2? | Encrinital limestone. Flint shale with Crinoids. 
are Delthyris shaly limestone. \ ‘lime shales with Zentaculites, 
4 | Lower Pentamerus limestone. Meristetla, &e. 
iC Water lime (Tentaculite bed). Massive limestone with Ptery- 
: gotus and Lep. alta. 
i 
© | Magnesian rock. 
& | Vermicular rock. 
s 1 Gypseous marls, Gray, calcareous shale. 
© | Variegated shale. Variegated shale. 
© | Red Shale. Red shale. 
Passage-beds. 
_ [ Limestone. Limestone and hsematite. 
Be Sandrock, 
z Iron ore. Teematite. 
br 4 Sandrock. 
= | Upper green shale. Upper green shale and fossil ore, 
= Tron ore and limestone. Iron sandstone and fossil ore, 
~ | Lower green shale. Lower green shale, 
Medina sandstone, 
ERRATUM. 
In Mr. Branner’s paper on the growth of the Palm, for Guéliand, 
read Guillaud ; and for Ser. VI, 176, 1877, read, Ser. V, L—176 1877. 
