CORRELATION OF FORMATIONS, 307

that of New Jersey shows a remarkable similarity with the Magothy-
Matawan horizons. Out of the 43 species found in the Black Creek
that have been recognized in the New J ersey Cretaceous, 23 are con-
fined to the Magothy-Matawan, while 20 pass upward into the Mon-
mouth. Of the 23 restricted forms in New Jersey 19 are similarly
restricted in North Carolina. On the other hand, of the 20 species
which range upward into the Monmouth in New Jersey 7 also range
upward into the Peedee in North Carolina, and this similarity may be
still more marked when more complete collections have been made from
the Peedee beds. The 19 forms common to and confined. to the Black
Creek formation in North Carolina and to the Magothy and Matawan
formations in New Jersey are:
Nucula percrassa Conrad, Nemodon brevifrons Conrad, Trigonoarca
triquetra Conrad, Trigonoarca cliffwoodensis Weller, Glycymeris con-
gesta (Conrad), Pterea petrosa Conrad, Exogyra ponderosa Roemer,
Ostrea cretacea Morton, C'ymella bella Conrad, Eriphyla conradi (Whit-
field), Cardium eufaulense Conrad, Isocardia cliffwoodensis Weller,
Schizodesma appressa Gabb, Corbula carolinensis Conrad, C. bisulcata
Conrad, Cadulus obnutus (Conrad), Gyrodes crenata (Conrad), Turri-
tella quadrilira Johns, Pugnelius densatus Conrad, Placenticeras pla-
centa (DeKay).
It is of interest that among these, T'rigonoarca triquetra Conrad,
Trigonoarca cliffwoodensis Weller, and Ostrea cretacea Morton are con-
fined to the Magothy alone, while Exogyra ponderosa Roemer, Eriphyla
conradi (Whitfield), Cardium eufaulense Conrad, Isocardia cliffwood-
ensis Weller, Cadulus obnutus (Conrad), Gyrodes crenata Conrad, Pug-
nellus densatus Conrad, and Placenticeras placenta (DeKay), have only
been found in the Matawan. The remaining forms have been found at
both horizons.
Ostrea tecticosta Gabb, Trigonia eufalensis Gabb, and Turritella
trilira Conrad, which have not been found above the Matawan, range
‘into the Peedee in North Carolina. On the other hand, out of the 20
Black Creek forms which are found in both the Magothy-Matawan and
the Monmouth, Cucullaea antrosa Morton, Ostrea pluwmosa Morton,
Gryphaea vesicularis Whitfield, Lima reticulata Forbes, Anomia ar-
_gentaria (Morton), and Cardium spillmani Conrad are also found
in both the Black Creek and Peedee in North Carolina, while the
remainder, which range upwards into the Monmouth, have not been
hitherto observed in the Peedee of North Carolina. Of these, however,
Cyprimeria densata (Conrad) and Linearia metastriata Conrad are
especially characteristic of the Matawan formation in the northern

Coastal Plain, although also found higher in the series.