The Portland daily press., 1883-09-26

large quantities. Among the foraminifera,
globigerina is abundant; but many other
forms occur, some of them of large size and
elegant in form. Grains of green sand (glu-
conite) were frequently met with, but were
not abundant. Large quantities of the
tubes of annelids frequently occur Some
of these are made of cemented mud, fine
sand or of gravel; others, Of parchment like
secretions. On the inshore plateau, and al
so in the deeper localities on the slope, there
is usually more or less genuine mud or clay;
but this is generally mixed with considera-
BILE fine sand, even in three hundred or six
hundred fathoms. The sand, however, is
often so fine as to resemble mud, and is fire.
quently so reported when the preliminary
soundings are made. In several localities
the bottom was so ''hard," in 65 to 125 faith
oms, that the bulk of the material brought
up consisted OF sponges, worm tubes, shells,
ETC., with some gravel, but with neither mud
nor fine sand. Such bottoms were very rich
in animal life. In many instances, even in
our deeper dredgings (about 700 fathoms),
and throughout the belt examined, we have
taken numerous pebbles and small rounded
boulders of all sizes, up to several pounds In
weight, consisting Of granite, syenite, mica
schist, etc. These are abundant in some
localities, and covered with actinie, etc.
Probably, while frozen into the shore ice in
winter and spring, they have been recently
foated out from our shores and rivers and
dropped in this region where the ice melts
rapidly under the influence of the warmer
gulf stream water. Probably much of the
sand especially the coarser portions, may
have been transported by the same agency.
Another way, generally overlooked, in
which fine beach sand can be carried long
distances out to sea is in consequence OF its
floating on the surface of the water after 1t
has been exposed TO the air and dried on the
beaches. The rising tide carries off con-
siderable amount of dry sand floating in this
way In our fine towing nets we often take
more or less fine silicious sand which is evil
IDENTIFY floating on the surface, even at con-
siderable distances from the shore. The vast
sand beaches, extending from Long Island
to Florida, afford an inexhausiiDle supply OF
this fine sand.
The prevalence of fine sand along the
Gulf Stream slope in this region and the
remarkable scarcity of fine mud or clay de-
posits indicate that there is here, at the bot
tom, current usually sufficient to prevent
for the most part the deposit ltion of fine ar
gillaceous sediments over the upper portion
of the slope in 65 to $50 fathoms. Such me-
terials are probably carried along for the
greater part till they eventually sink to
greater depths, nearer the base of the slope,
or beyond in the ocean basin itself, where
the currents are less active. Doubtless
there are also belts along which the northern
current meets and opposes the Gulf Stream,
causing less motion, and favoring the depo-
stion of the fine sediments. 1t is probable
the motion of the water along the upper
part of the slope may also be caused by tidal
currents, which would modify the north
eastern flow of the Gulf Stream, both in di-
rection and velocity. Currents produced by
protracted storms might have the same
effect In depths greater than 200 fathoms
on the outer slope, and in twenty-five to
sixty fathnms on the inshore plateau, there
is doubtless a slow, cold current TO the
southwest. 1t is not probable that these
bottom currents are strong enough to move
even a finer sand after it has once actually
reached the bottom; nor is it strong enough
to prevent the general deposition OF oceanic
foraminifera, pteropods, etc.
The existence of actual currents in this
region, sufficiently powerful to directly effect
an erosion of the bottom, is hardly supposa-
BILE. Such result may be effected, how
ever, in consequence of the peculiar habits
of certain fishes and crustacea that abound
on these bottoms. Many fishes, like the
hake (phycis), of which three species are
common here, have the habit of roofing in
the mud for their food, which consists
largely of annelida and other mud burrow-
ing creatures. Other fishes, those with
sharp tails especially, burrow actively into
the mud or sand, tail first; and in all prob
ability macrurus, abundant on these slopes,
has this habit. Several burrowing species
of true eels and eellike fishes are very abun-
dant on these bottoms, Many of the crabs
and other crustacea are active burrowers.
Such creatures, by continually stirring up
the bottom sediments, give the currents
chance to carry away the finer and lighter
materials leaving the coarser behind.
In many localities there are great quanti-
ties of dead shells, both broken and entire.
A small portion of the unbroken bivalves
have been drilled by carniverous gastropods,
but there are large numbers that show no
such injury These have for the most part
undoubtedly served as food for the starfishes
and large actinie, abundant on these
grounds, and from which have often taken
many kinds of entire shells, including deli
cate pteropods. Many fishes, like the cod,
haddock, hake, founder, etc., have the habit
of swallowing shells entire, and after digest
ing the contents they disgorge the uninjured
shells. Such fishes abound here. Species
of octopus are also known to feed upon BIZ
valves without breaking them, and o. Bair-
dii is common in these depths. The broken
shells have probably been destroyed in large
part by the large crabs and other crustaceans
having claws strong enough to crack the
shells. The large species of cancer and ger
yon and the larger PGguri. abundant in this
region, have strength sufficient to break
most of the biValve shells. Many fishes that
feed on molusca also crush the shells before
swallowing them. Both fishes and crabs
have, doubtless, thus helped to accumulate
the broken shells that are often scattered
abundantly over the bottom, both in deep
and shallow water. Such accumulations of
shells would soon become far more extensive
than they are, if they were not attacked by
boring sponges and annelids. Certain COM
mon spOnges, belonging to the genus Cliona,
very rapidly perforate the hardest shells in
every direction, making irregular galleries,
and finally utterly destroying them. On the
outer grounds we dredge up rarely frag-
ments of wood; but these are generally per-
forated by the borings of bivalves usually
XyIophqgd dorSdHs) and other creatures,
and by them would evidently be soon de-
stroyed.
We very rarely meet with the bones of
vertebrates at a distance from the coast.
Although these waters swarm with vast
schools of fishes, while sharks and a large
sea porpoise, or dolphin (DelphinatS, sp.),
often occur in large numbers, we very rarely
dredge up any of their bones. In few in
stances we have dredged single example Of
a sharks tooth, and occasionally the hard
otoliths of fishes. 1t is certain that not
merely the flesh, but most of the bones also,
of nearly all the vertebrates that die in this
region are very speedily devoured by the
various animals that swarm on the bottom.
Echini are very fond of fish bones, which
they rapidly consume. Fishes caught on
the hook in this region and left down an
hour or two, were nearly stripped of their
flesh by small amphipod crustacea.
Relics of man and his works are Of ex-
tremely rare occurrence at a distance from
the coast, or even at a short distance out
side of harbors, with the exception of the
clinkers and fragments of coal thrown over
board from steamers with the ashes. As
our dredgings are in the track of European
steamers such materials are not rare. A few
years ago even these would not have oc-
Cured. A rock forming on this sea bottom
would therefore, not contain much evidence
of the existence of man, nor even OF the
commonest fishes and Oetaceans inhabiting
the waters.