6g 
STRANGE DWELLINGS . 
species, the Fork-tailed Date Shell (Lithodomus caudiger a), is able 
to bore into substances which the pholas cannot penetrate. It is 
truly a wonderful little shell. Some of the hardest stones and 
stoutest shells are found pierced by hundreds of these curious 
beings, which seem to have one prevailing instinct, namely, to 
bore their way through everything. Onwards, ever onwards, 
seems to be the law of their existence, and most thoroughly do 
they carry it out. They care little for obstacles, and if one of 
their own kind happens to cross their path, they quietly proceed . 
with their work, and drive their tunnel completely through the I 
body of their companion. 
The precise method employed in excavation is at present un- 
known, for the shape of the shell, and the exactitude with which 
it fits the burrow, prove that the mollusc does not form its tunnel 
by means of the protuberances on the surface of the shell, and 
no other method of boring has at present been discovered. 
Those who are fond of wandering on the sea-shore, will often 
have experienced tangible proofs of the existence of another 
burrowing mollusc, the Razor Shell ( Solen ensis). 
In some parts of our coast it is impossible to walk on the 
mixed rock and sand, when the tide has receded, without no- 
ticing innumerable jets of water, which start from the ground 
without any perceptible cause, leap for a foot or so in the air and 
then disappear. On watching one of these miniature fountains, 
and looking at the exact spot whence it proceeds, two little 
round holes are generally seen in the sand, so close to each 
other as to resemble a keyhole, and large enough to receive an 
ordinary goosequill. If the finger be placed on the spot, or even 
if the foot descends heavily on the ground, the curious object 
vanishes far out of the reach of a probing finger. The jets are 
thrown up by the Solen, and the two little holes are the open 
extremities of the siphon, that wonderful instrument through 
which the creature obtains its nourishment. 
The reader will remember that the wood-bearing pholas 
always makes its burrow across the grain of the timber which it 
