JUNE 1906. DEVONIAN FossILS—SLOComM. 261 
only in and below the Encrinal limestone at Eighteen Mile Creek, 
but at Bethany it occurs both above and below. Stropheodonta 
demtssa is found throughout the series at Bethany, and also at Thed- 
ford, but at Eighteen Mile Creek it is reported in the Encrinal bed 
and below, and at Cayuga Lake only in the Hamilton. Tvropidoleptus 
cartmatus is found through the series at both Bethany and Cayuga 
Lake, but at Eighteen Mile Creek in the Encrinal limestone and be- 
low, and at Thedford only in the Hamilton. | 
It is of interest to note that in the Bethany fauna the range of 
some species, e.g. Aulopora serpens and Tropidoleptus carinatus 
corresponds to the Cayuga Lake fauna; that of others, e. g. Stroph- 
eodonta demissa, corresponds to the Thedford fauna, and Stropheodonta 
concava and Favosites argus have as great a range at Bethany as at 
all the other localities combined. Hence it is not safe to determine 
the position of isolated beds, in regard to the Encrinal limestone, 
by the composition of the fauna. A similar conclusion was reached 
by Cleland* in his study of the Hamilton beds at Cayuga Lake. 
The following table represents the amount of material collected 
by the writer, with the exception of the bryozoans from “B8.” Of 
these a large series, both of species and specimens, was secured, but 
as they have not yet been identified, they are not included. The 
figures against each species in the table indicate the number of speci- 
mens collected by the writer. The letters indicate that the same 
species have been reported by other authors from Thedford, Eighteen 
Mile Creek, or Cayuga Lake, and the particular letter indicates the 
bed in which they were found. Thus M, indicates Moscow shale; 
E, Encrinal limestone, and H, Hamilton shale. The papers con- 
sulted for mention of these species are the following: Hamilton 
Group of Thedford, Ontario, by H. W. Shimer and A. W. Grabau, 
Bull. Geol. Soc. Am. Vol. 13, p. 149, 1901; Geology and Paleontology 
of Eighteen Mile Creek and the Lake Shore Sections of Erie County, 
Dye Gtabau, Bull Buffalo Soc. Nat. Sci. Vol. VI, 1899;° A 
Study of the Fauna of the Hamilton Formation of the Cayuga 
Lake Section in Central New York, by H. F. Cleland, Bull. 206, U.S. 
Geological Survey, 1903. 
Tee 2004s 9. \Cr,49.,.f). OF 
