The Monitor. [volume] (Woodstown, N.J.) 1884-1892, 1885-08-14
NEW JERSEY MARL.pITs.

SAlil tOltDfil " lLli idffls lis DptbDui n MIA
ture Of marsh and dirt-heap overgrown
with vegetation. 1t is not the spot that
would be chosen by the poet or the painter,
yet it is full Of interest, for it contains the
record of a long era in the history of this
planet. When the friable greenish material
which is here dug out for use as fertilizer
was deposited, the sea rolled over what is
now New Jersey. The land Of gardens
now stretches from Amboy to Trenton
and southwark to Cape May, did not then
exist. The older rocks of Pennsylvania
and Northern New Jersey were in their
present position, but the eroding action
of the constantly falling rains and run
ming waters had not scooped them into
hollows as picturesque as those which
now diversity the country. Fishes not
altogether unlike those which now exist.
yet recognizably different, nollusks of
various kinds: cuttle-fishes, widely differ
ent fIom those now living; gartropods or
univalves aud lamellibranchiates or biy-
alyes, mostly Of families and even genera
which still have many living members;
brachiopods of arm footed sheIl-bearing
creatures; sea-urchins and other tribes OF
aquatic animals peopled the sea, while
the great reptiles of various kinds were
the tyrants of sea and land. The
brachiopods are mostly extinct. the great
reptiles have all passed out of existence.
but sea-urehins very closely related to
those of the mari and kindred beds still
live in our seas. In that far-off cretaeeous
age when the marls were deposited there
were no mammals-n0 warm-blooded and
air-breathing animals-their place was
occupied by cold-blooded air-breathers,
gigantic saurians, many of which almost
equalled the elephant in bulk. though none
seem to have approached the whale. As
mammals increased, reptiles declined, un-
til i'll the present age all are small save
few serpents and the crocodiles-tIc last
probably direct descendants OF the cretaee-
Gus crocodiles But the mosasaurs and
other huge reptilian beasts which inhabit-
ed the ocean. and the hadrosaurus, diclonius
laelaps and others which haunted the
marshes. have vanished completely, leay-
ing as record of their existence only few
skeletons or fragments of skeletons which
CHANGED to be so covered over that they
were preserved from decay. All this and
much more has been learned from the
marl-pits and from other beds in Europe
and in the far West of America.
Only very small part of all this can be
learned from a single trip to the pits, yet
to take such trip, to unearth with ones
own hand shell, the vertebra Of a shark,
the cast of the guard of beemnite, or the
spines of a sea-urchin, is to realize the truth
of that long past more wildly than books
can bring it before us. A large part of the
green sand or mari (as it is miscalled, for
true mari is clay and lime) is composed Of a
mineral known as glauconite, which exists
as little pellets. By the use OF the micro
scope the shapes of large number of tiny
shells can be made out. They are not the
shells themselves, only casts of them. The
shells have been dissolved away, but not
until the hollow chamber once occupied by
the jelly-like organism which made them
had been filled by glauconite, the materials
of which exist in sea water. The cretace-
Gus sea, therefore, like the present one,
was full of what are called foraminifera.
living bits of jelly, without mouth or
stomach, as well as without heart or nerves.
yet capable of secreting shelly covering
of carbonate of line, and able to take food
by means of Jelly feet thrown out for the
purpose The mari contains much phos-
phatie material. probably derived largely
from the decomposition of bone-the bones
of reptiles and fishes. For bone is more
destructible than she'll. and thus the mul-
luscious remains are most common.
Mnlliea Hill is not mari pit but it is
a natural exposure of eretaeeous beds, and
is capped by a layer consisting almost
entirely of shells. which. though evidently
oysters, are unlike any oyster now living.
One kind is very large, much twisted. and
ribbed: the other smooth and deep. Other
shells can be found. A party of about
twenty anxious students, armed with
trowels and fingers, and using their eyes
well, succeeded in finding about as many
species, some of them in comparative album
dance The most common finds were the
cast of the internal shell Of the cuttle-fish.
Belemnitella micronata; the sea snails
Natica abissina and Natica halli the wing
shell Roseellaria pinnata, generally with
ont its broadly projecting lip, and the
oysters aforesaid; while the greatest rarity
found was a large Volnta conrad. which
was exhumed by sharp-eyed young school
teacher At STATIONS pits the character
of the fossils was different The shell bed
newer than that at Mullica Hill. was made
up almost entirely of an oyster and
terebratula while the layer next above
yielded the spines of sea urehins of the
genera and ciddTfs sdleHid, and tubes of a
teredo. The teredo or ship worm of those
ancient days had no ships nor extensive
wharves or piles in which to luxuriate. and
must have bored into other substances. In
another pit fragments of sharks vertebra
were found. 1t is not given to every one
to disinter crocodile or hadrosaurus, SO
with these and with a lump of genuine