CHAPTER III. 
FORMATIONS OF ORDOVICIAN AGE. 
KITTATINNY LIMESTONE. 
The top of the Kittatinny lmestone in New Jersey is not a con- 
tinueus horizon, as there is an erosion interval between it and the 
Trenton limestone, the next succeeding formation. At many localities 
the highest beds are doubtless Cambrian in age, but the remnants of 
beds bearing a younger fauna than that characterized by Dvikelo- 
cephalus are present in at least one locality. These strata seem not to 
be separated by any physical break from those bearing the Cambrian 
fauna, and the deposition was doubtless continuous from early Cam- 
brian time until after the opening of the Ordovician, as usually under- 
. stood. The single locality in the Kittatinny lmestone which has 
afforded this early Ordovician fauna is in the railroad cut of the 
Delaware branch of the New York, Susquehanna and Western rail- 
road at Columbia (Locality 210 A). The limestone at this point is 
somewhat thinner bedded than usual for the formation, the beds being 
frequently separated by thin, shaley partings. Similar strata occur 
along the railroad at Hainesburg, near the top of the formation, and 
they, too, may be of Ordovician age, although no fossils have been 
found at that locality. At Columbia the Trenton lmestone outcrops 
only a short distance up the hillside from the railroad cut where 
the fossils occur, so that the position of the fauna near the top of the 
Kittatinny limestone formation is assured. The following species of 
fossils have been recognized: 
. Dalmanella wempler Cleland. 
Dalmanella electra (Bill.). 
Syntrophia lateralis (Whitf.). 
Cyrtolites sinuatus H. & W. 
Bellerophon sp. undet. 
Raphistoma columbiana nu. sp. 
Inospira sp. undet. gt 
Ophileta? sp. undet. 
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