418 
CLASS ARACIINIDES. 
names Epe'ire de Vopuntia (Annal. cles Scienc. Phys. V. lxix. 
3), because it constantly remains at the middle of the leaves of 
the agave and opuniia , and there establishes its toils by means 
of a net-work, with loose threads, and irregularly interlaced. 
It is black, with white and inclined hairs, forming the appear- 
ance of scales. Its abdomen has on each side two pyramidi- 
cal tubercles, and terminates posteriorly with two others, but 
obtuse, and separated by a broad emargination. The posterior 
face of each of these pyramidical tubercles presents a spot of 
a fine snow-white. These spots are connected with one ano- 
ther, and with one or two more which are posterior to them 
by white zig-zag lines. These tubercles do not exist in indi- 
viduals which are but just born. The cocoons are oval, 
whitish, and formed of two tunics, the interior of which is a 
species of wadding enveloping the eggs. We often find seven, 
eight, and even ten of these cocoons in file, one after the other. 
This species inhabits Catalonia and the kingdom of Valencia. 
Among the exotic species there are some very remarkable. 
Some have the abdomen invested with a very firm skin, with 
corneous points or spines ; others have bundles of hairs to the 
feet. 
We shall now^ pass to spiders, sedentary, like the preceding, 
but which can walk sideways, backwards, and forwards ; in a 
word, in all directions. This is the section of Laterigrade 
Spiders. The four anterior feet are always longer than the 
others ; sometimes the second pair exceeds the first, and some- 
times they are nearly equal. The animal extends them in 
their whole length on the plane in which it is situated. 
The forceps are usually small, and their hook is bent trans- 
versely, as in the four preceding tribes. Their eyes are always 
eight in number, often very unequal, and form, by their union, 
the segment of a circle or a crescent ; the two lateral posterior 
ones are more removed backwards, or more approaching the 
lateral edges of the corslet than the others. The jaws are in 
13 
