CHAPTER VII. 
FAUNAS OF ORDOVICIAN AGE. 
The Ordovician faunas in New Jersey represent two distinct hori- 
zons, and the strata containing them are separated by a conspicuous 
physical break. The oldest Ordovician fauna represents the Beek- 
mantown ( =Calciferous) stage of the New York series, and occurs 
in the uppermost beds of the Kittatinny limestone, with no apparent 
physical break separating the strata from those bearing a Cambrian 
fauna. This fauna has been found at but a single locality—near 
Columbia. 
The younger Ordovician fauna represents, in general, the Trenton 
stage of the New York series, and occurs in strata which le uncon- 
formably upon the Kittatinny limestone, with a basal conglomerate - 
between them. The limestones bearing the Trenton fauna have a wide 
distribution through the Kittatinny valley, in the northwestern por- 
tion of the State, and are usually more or less fossiliferous, although 
the fossils are frequently poorly preserved. 
These two Ordovician faunas will be described separately, the first 
one which occurs in the upper strata of the Kittatinny limestone 
being the older. 
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