FORMATIONS OF DEVONIAN AGE. 103 
ONONDAGA LIMESTONE. 
The Onondaga (Corniferous) limestone proper is restricted to the 
Delaware valley region of New Jersey, although beds of similar age 
are represented in the Green Pond region. The formation les above 
the Esopus grit, and covers the greater portion of the northwestern 
slope of the Wallpack ridge. ‘Towards its base the formation is some- 
what shaley, and there is apparently a rather gradual transition from 
the subjacent Esopus grit to the Onondaga limestone. The limestone 
is a hard, regularly-bedded rock, the beds ranging in thickness from 
three inches to a foot. Some of them contain large quantities of 
chert, which give to their weathered surfaces an extremely rough 
and jagged appearance. Fossils are not abundant in this formation, 
and those that are present are usually too firmly imbedded in the 
matrix to be satisfactorily studied. 
Locality 2 B.—Along the river road, about two and one-half miles 
below Tri-States, New York, there are several outcropping ledges of 
this formation, from which the following species of fossils were 
collected : 
1. Stropheodonta perplana (Con.). 
2. Atrypa reticularis (Linn.). 
3. Loxonema sp. undet. 
Locality 37 D.—In a field about three-fourths of a mile northwest 
of Peter’s Valley there are good exposures of the Onondaga limestone, 
in which some fossils are present. Most of these are corals, too firmly 
imbedded in the. matrix to be collected, and some crinoid columns; 
the only species of brachiopod observed was Leptena rhomboidalis. 
Locality 52 A.—One of the best fossil localities which has been 
observed in the Onondaga limestone of New Jersey is at the side of 
the river road, one and one-half miles southwest of Peter’s Valley. 
The following species have been identified from there: 
1. Fenestella? sp. undet. 
. Stropheodonta perplana (Con.). 
. Chonetes arcuatus Hall. 
. Rhipidomella vanuxemi (Hall). 
. Atrypa reticularis (Linn.). 
. Reticularia fimbriata (Con.). 
. Anoplotheca concava (Hall). 
fa) 
2 SD Tre WH 
