ORDER I. PULMONARIA. — WATER SPIDER. 265 
threads, so that from each spinneret proceeds a series of threads forming 
one compound whole; these are situated about one third of an inch from 
the apex of the spinnerets; they also unite and form one thread, six hun- 
dred and twenty-four of which are used by the spider in forming his net. 
With the instrument which nature has given him, —the claws of his feet, 
— the spider guides and arranges the glutinous thread as this seemingly in- 
exhaustible fibre is drawn from his body, and interweaves them with each 
other until the web is complete. In this way spiders are weavers of a 
supple line, whose touch, for quickness and fineness, surpasses that of any 
spinning-jenny. 
A. Domestica, — These animals are found everywhere. They construct 
in our houses, in the angles of walls, upon plants and hedges, in the ground 
or under stones, large webs nearly horizontal, at the upper end of which is 
a tube in which they station themselves. 
A. Aquatica.—The Water Spider. This animal is blackish-brown, 
with the abdomen darker colored, silky, and with four impressed dots on 
the back. It resides in standing water, in which it swims with the abdomen 
encased in a bubble of air, and in which it forms for its retreat an oval cell 
filled with air and formed of silk, from which threads proceed to the different 
adjacent water plants in all directions. Here it devours its prey, constructs 
its egg-case, which it carefully guards, and where it passes the winter, hay- 
ing first closed the cell. 
Another species of weaving-spider (petra diadema, Linn.) is of a 
large size, with the abdomen marked with a triple cross formed of small 
white spots. It abounds most in autumn. The eggs, which the parent 
deposits at the commencement of the cold weather in angles of the ceilings 
of rooms, in passages, near gardens, and in walls, enveloping them with a 
loose, white silken web, are hatched in the spring of the following year. 
Another singular species is described by Dufour under the name of Uroc- 
tea maculata. “It is about half an inch long, of a brown maroon color, 
with the abdomen black, marked with five yellowish spots. Found in the 
south of Europe and Egypt. Dufour has made some curious observations 
on its habits. It constructs on the under side of stones, or in crevices of 
rocks, a cocoon in the shape of a cap or patella an inch in diameter, its cir- 
cumference having seven or eight festoons, the points alone being fixed to 
the stone by means of threads, whilst the edges of the festoons are free. 
This singular tent is of an admirable texture, the outer surface resembling 
the finest taffety, and composed of a number of folds. When young it only 
constructs two layers, between which it takes its station. But subsequently, 
perhaps at each moulting, it adds additional folds, and when the period of 
reproduction arrives, it weaves another apartment, expressly for the reception 
