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air. This is the way it accomplishes the task : It introduces air, 
one bubble at a time, until the water is expelled, and its home is 
then almost exactly on the principle of the modern diving bell. 
The introduction of air is a curious and marvellous feat. The 
spider rises to the surface, and turning its body with a sudden 
spring entangles a bubble of air by a peculiar way of turning its 
body and crossing its legs. Then descending and keeping the 
bubble of air under itself, as a man might do under the hollow of 
his inverted hand if he were quick enough, she carries it quickly 
down and passing iiqder the bell, the air is released, and rising to 
the top expels from the bell so much water. She does this many 
times in quick succession until there is space enough in the nest 
for her purpose ; she then takes her position head downward and 
waits for her prey. 
Another species of aquatic spider is called the Raft spider. It 
runs easily on the top of the water, but that it may have a resting 
place for devouring its prey, it gathers a number of leaves, winds 
about them a few turns of silk to hold them together, and mount¬ 
ing on this frail bark sets sail in search of booty. The breeze and 
the little waves of a pond are the propelling force. The aquatic 
insects that come to the surface, gnats which obtain their wings on 
the surface of the water and are still too weak for flight; insects 
which are themselves skating about on the water in search of their 
own prey, and land insects which fall into the water by accident 
become the victims of our brave privateersman. Occasionally he 
darts from his raft for some tempting insect, and having seized it 
returns on the surface of the water to his ship to devour it. This 
spider is of a very brilliant appearance, its general color being a 
rich, chocolate brown, the outline of the upper part of the abdo¬ 
men and thorax is marked out by a broad band of orange, with 
white spots underneath, while the legs are a pale red. Altogether 
a dandified and gayly decorated pirate, gotten up regardless of ex¬ 
pense. 
We come now to the true web-builders, the spinners and 
weavers of nets. I shall endeavor to describe three classes of webs : 
First. There is the regular geometric web of the common gar- 
o O o 
den spider, though it is doubtful whether there is ever found a true 
geometric web. In a geometric web, truly such, the concentric 
