308 
ARACHNIDES. 
short and broad trapezium ; there are four before in a transverse 
line; two others, more internal than the two last of the preceding’ 
ones, form a second transverse line ; the last two are behind the two 
preceding ones. The chelicerae are stout. The jaws are rounded, 
and very hairy at the end. The ligula is nearly square ; somewhat 
longer than broad. The legs are long, and almost filiform; those of 
the fourth and first pairs are the longest of all. The thorax seems to 
be divided into three parts, of which the anterior is much the largest 
and square; the two others resemble knots or humps. The abdomen 
is much shorter than the thorax, and is covered with a solid epidermis, 
from its origin to the middle. 
The Myr. fulva, on which I have established this genus, inha- 
bits Brazil ; other species, however, appear to be found in Geor- 
gia, United States of America. 
In the second section of the Vagabundce, that of the SaltigraDjE, 
called by others Araignees phalanges, the eyes form a large quadrila- 
teral, the anterior side of which, or the line formed by the first ones, 
extends aci’oss the whole width of the thorax ; this part of the body 
is almost square or semi-ovoid, plane, or but slightly convex above, as 
Avide anteriorly as in the rest of its extent, and descending suddenly 
on the sides. The legs are fitted for running and leaping. The 
thighs of the two fore legs are remarkable for their size. 
The Araignee a chevrons blancs of Geotfroy, a species of Sal- 
ticus very common in summer on walls or windows exposed to 
the sun, moves by jerks, stops short after a few steps, and raises 
itself on its fore legs. If it discover a fly, or particularly a mus- 
quito, it approaches softly, and then darts upon the victim with a 
single bound. It leaps fearlessly and perpendicularly on a wall, 
being always attached to it by a thread, which lengthens as it 
advances. This same filament also supports it in the air, enables 
it to ascend to its point of departure, and allows it to be wafted by 
the wind from one place to another. Such, generally, are the 
habits of the species that belong to this division. 
Several construct nests of silk resembling oval sacs open at 
both ends, between leaves, under stones, &c. Thither they 
retire to change their tegument and to seek shelter in bad 
weather. If danger menaces them there, they leave it at once 
and escape with speed. 
The females construct a sort of tent, which becomes the cradle 
of their posterity, and in which the young ones, for a time, live 
in common with the mother. 
Certain species, resembling Ants, elevate their anterior legs 
and make them vibrate with great rapidity. 
Singiilar combats sometimes ensue between the males, but no 
fatal issue occurs. 
A subgenus established by M. Rafinesque, that of 
Tessarops, 
Appears to us to approximate closely to the following one in most 
of its characters and habits, but to be widely removed from it, if there 
