ORDER PULMONARI^. 429 



trapezium. There are four in front on a transverse line ; two 

 others, more interior than the two preceding extreme ones, 

 compose a second transverse line ; the last two are behind the 

 two preceding ; the forceps are strong ; the jaws are rounded,' 

 and very hairy at the end ; the tongue is almost square, a little 

 longer than broad ; the feet are long, almost filiform ; those of 

 the fourth, and the first pair, are the longest of all ; the thorax 

 seems divided into three parts, the anterior of which, much 

 larger, is square, and the other two in the form of knots or 

 bosses ; the abdomen is much shorter than the thorax, and 

 covered from its origin to its middle with a solid epidermis. 



Myrmecia fulva, on which I have established this genus, 

 is found in Brazil. But it appears that other species of it 

 exist in American Georgia. 



The second section of Erratic Spiders, that of Salti- 

 GRADES, has the eyes disposed in a large quadrilateral figure, 

 the anterior side of which, or the line formed by the first, 

 extends through the whole breadth of the corslet ; this part of 

 the body is almost square, or semi-ovoid, plane, or but little 

 gibbous above, as broad in front as in the rest of its extent, 

 and falls abruptly on the sides ; the feet are proper both for 

 running and leaping. 



The thighs of the two fore-feet are generally remarkable for 

 their size. 



The spider a chevrons hlancs of GeofFroy, a species of 

 Salticus, very common in summer on walls or glass-windows 

 exposed to the sun, walks as it were by jerks, stops short after 

 having made a few steps, and raises itself on the anterior feet. 

 If it discovers a fly, or a gnat more especially, it approaches 

 quite softly within a distance which it can clear at a jump, and 

 then instantly darts on the animal which it was watching. It 

 does not hesitate to leap perpendicularly from a wall, in con- 

 sequence of the thread of silk which attaches it, and which it 

 unwinds in proportion as it advances. This also serves to 



