The Manitowoc pilot. [volume] (Manitowoc, Wis.) 1859-1932, 1902-10-02
CLANS THAT BORE IN ROCKS.
An interchangeable Miner of the Mol
Iusk World That Affords Ma
turaIists Much Interest.

One of the strangest mollusks known
to science is the Piddock, or "Horing
clam" belonging to the family Of
! Pholes. The members Of this curious
family bore into the sandstone lodges
| skirting the sea. and there take mp
permanent abode, where they can be
found imbedded at varying depths in
the rock.
Belonging to a family that is scat
| tered Worldwide, Piddocks have re
ceived considera BILE attention at the
hands of naturalists from the earliest
times. But inhabitiug as they do only
| those portions Of the lodges that are
never laid bare save at extreme low
tide, their movements are SO screened
from mans prying eye that To this day
| they remain somewhat Of an enigma,
writes James G. MeCurdy, i'll Scien-
| ttic American.
Many old ruins along the sea, as we'll
as the rocky coast itself, bear traces of
this indefatgable miner Of the lower
world. The marble columns Of the an
cient temple Of Jupiter Scraps, stand
ing upon the shores of the Meditcr-
ranean sea. are said to be chiscled
deep by the Piudocks of hygoue days.
"How do they get into the rock?' is
question Invariably asked by those
who for the first time see the Piddochs
in their peculiar habitations. Author
tiles have been greatly divided upon
the subject. Some have held that the
creatures secreted an acid that ate the
rock, while others have declared that
it was by long-continued action Of the
tongue that the burrows were eNca-
waited.
Both of these theories can be safely
discarded, MS it is now universally be
lieved that the clam burcs into The rock
by aid of its sharp shell, which is re-
placed by secretions as fast as il is
worn away. The muscular foot which
can he thrust forth at Will i'm the work
ing form, being clamped to- the rock,
forms a fulcrum about which The sharp
shell can be brought 70 bear in any
direction. Raspings on the walls OF
the burrow show CouclusiSely that the
shell is used in drilling.
Several species Of Piddocks arc
found on the shores of Puget Sound,
some inhabiting the hard clay banks
bordering on the sea, while others Sc
lect exclusively the sandstone lodges
as places Of abode. Those living in
the clay banks are larger and tougher
than the rock dwellers. The latter are
~ a.
are as n rule buried about six inches
in the ledge. | have found specimens
over four inches long, Embedded fully
eight inches deep.
They are roughly oblong in shape,
the inner end being large and rounded,
while the outer end is iattcned and
| terminates in long tongue or siphuu.
| The siphon lies in the small, tubclike
passage which affords the Paddock the
| only means of communications with the
outside world, and is usually thrust
out to the surface ready to extract the
! animalcules from the sea water, upon
which the clam feeds. At the first APP
proach of danger, the siphon is with
drawn and the burrow closed TO in
truders by means of the long, leathery
combinations of the shell.
The shell of the mollusk is thin and
brittle. The flesh is very tender and
palatable, and along the Oregon coast,
where the Piddock is plentiful, Rock
Oyster Soup" as it is called, is CON
sidered great delicaey.
That the creature does its boring
| while small is evidenced by the bur
| row, which is rarely over one-quartcr
of an inch in diameter at the surface
of the rock. The passageway increases
in size at n uniform rate, and contains
no lateral ndentations, showing that
the Paddock had not stopped for any
length Of time at any given spot, while
continuing its boring operations.
When the desired depth is attained.
| the clam ceases from its labors. cx-
cepting TO enlarge the cavity in which
| it lies, as its growth nccessitates. Aft
er disseminating its boring, its muscu-
lar foot is gradually absorbed and
| the orificc through which il formerly
| protruded closes up.
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