20 
MUSEUM BULLETIN NO. 3. 
that of the cataract formation of Schuchert ; but if the long ranging 
species be not considered, there are only three species common to 
the two formations, while most of the Cataract species make their 
first appearance in strata higher in the Anticosti section than the 
Becsie River formation, and, since the general expression of the 
Cataract formation is younger, it is concluded that there is little 
basis for equivalence and that the Cataract should probably be 
correlated with the lower portion of the succeeding formation. 
A fauna holding a stratigraphic position somewhat similar to 
that of the Becsie River is that of the Alexandrian series of Illinois 
and eastern Missouri ; but of the total fauna of that series, there 
are only nine species which also occur in the Anticosti section 
and, since they are mostly species of extended vertical distribu- 
tion, their presence affords no basis for correlation. However, 
since four of the nine species do not appear in the Anticosti sec- 
tion until the upper zone of this, or the succeeding formation, and, 
also, since the general appearance of the fauna is younger than 
that of the Becsie River, it is believed that it will find a closer 
equivalence with the upper portion of this and some parts of the 
succeeding formation. 
The highest zone of the Gun River formation shows the ap- 
pearance of typical Clinton species, but the Clinton faunal assem- 
blage does not attain full development until the succeeding Jupiter 
River. Since the Jupiter River fauna correlates best with the 
higher New York Clinton, the Williamson shale, and the Ironde- 
quoit limestone, this being particularly true for that part lying 
above zone 2, it is considered probable that the lower zones of 
the New York Clinton, the Sodus shale, Furnaceville ore bed, and 
Walcott limestone, find representation in the lowest zones of the 
Jupiter River and the highest zone of the Gun River, especially 
as the Walcott limestone carries the same diagnostic fossils as 
does zone 5 of the Gun River formation. It is further considered 
probable that the middle and lower zones of the Gun River for- 
mation are the Anticosti equivalents of the Cataract of southern 
Ontario and the Brassfield of the Ohio valley. An apparent 
reminder of the Brassfield appears in zone 5 of the Gun River 
formation in the occurrence of Triplecia insularis anticostiensis 
which then extends until zone 3 of the J upiter River. In a previous 
