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THE GEELONG NATURALIST. 
The sense of sight in the crab is peculiarly acute; they 
are able to distinguish objects at a very great distance, On 
examining the eyes we find that they are placed at the end of 
stalks or peduncles, giving the creature power to see in all 
directions, without altering the position of its body. On one 
occasion, while walking between Bream Creek and Barwon 
Heads, I saw hundreds of crabs belong to the species known 
as Sand Crabs, on the sea shore, disporting themselves in the 
sun; under cover of some wreckage I got within some fifty 
or sixty yards of them, but on my sudden appearance from 
cover a scene of activity in earnest began: the shore seemed 
to be alive with little circles, and in less time than it takes to 
tell this living mass had disappeared from the surface. . 
The antenna. and tips of the walking limbs are two very 
sensitive organs in these crustaceans; the most delicate touch 
on either of these organs will cause them to move, but it is 
not so on other parts of the body, the body being covered with 
a hard shell, tactile sensibility must be very slight; the 
acuteness of the other senses—sight and smell—would, 
I have no doubt, compensate for the slight sensibility over 
the general surface of the body. 
The habits of these creatures differ very much: some are 
strictly aquatic, and are only found at great depths in the 
sea; others are semi-terrestrial, living on shore in burrows or 
holes formed in the sand or marshy soil ; others are completely 
terrestrial. These semi-terrestrial and terrestrial crabs 
(known as the land crab) during spawning season will travel 
for miles to gain the sea shore in order to deposit their eggs. 
During our camp last Christmas we had the satisfaction 
of seeing an army of land crabs (Gecarcinide) . returning 
from the sea coast inland; these crabs are allied in all points 
of essential structure to other crabs, except in the gill cavity, 
the gills being of a leaflike appendage, which are kept in a 
moist state, by the retention of moist air admitted to the gill 
chamber through a special aperture. These creatures came 
down the sand dunes ten or twelve deep, the time we noticed 
their approach was about midnight, when we were on 
our way, lantern in hand, to the beach, to view the ocean by 
night, we stood right in the line of march of these creatures, 
to see if it would cause them to turn back, but to our surprise 
they only opened out their ranks, and after passing us closed 
in again; neither our light nor presence seemed to deter their 
onward march: evidently they were an army of determined 
crustaceans, : 
At daylight we traced their line of march, which could 
easily-be distinguished by the claw marks on the'sand, giving 
one the idea of a broad rake being drawn up and down and: 
