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 Mijr. fiilva, 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 Vagabundee, that of the Saltigkad.e, 

 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 across the Avhole width of the thorax ; this part of the body 

 is almost square or semi-ovoid, plane, or but slightly convex above, as 

 wide anteriorly as in the rest of its extent, and descending suddenly 

 on the sides. The legs are fitted for running and leajjing. The 

 thighs of the two fore legs are remarkable for their size. 



The Araignee a chevrons blancs of Geoffroy, 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, 8fc. 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. 



Singular 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 



