264 Mr. R. I. Pocock on the Genera and 
described. In such places many remains of beetles may be 
seen in the morning; and although I have not actually ob- 
served the spiders devouring the insects, I suspect that they 
feed largely upon them, for the sound of the spider’s dash is 
generally followed by a crumpling noise, such as would be 
produced by the crushing of a beetle between the spider’s 
jaws. ‘Their speed and energy is tremendous; but the natives 
do not consider them noxious, and, Somali-like, tell me there 
is no name for things so unimportant.” 
The following tables will show some of the differential 
features of the species known to me: — 
Males *. 
a. Upper mandibular fang furnished on the inner side 
or above at the base of the flagellum with a tooth 
against which the lower fang closes. 
a‘, Flagellum long, slender, simple, extending past 
the ocular tubercle ; protarsus of palp fuscous.. dentatidens, Sim. 
b'. Flagellum short, stout, toothed internally near 
the slender apex, which scarcely surpasses the 
basal lamina; palp wholly ochraceous........ Serox, Poe. 
b. pee mandibular fang without supernumerary 
tooth. 
a?, Upper mandibular fang with a long untoothed 
interval between the tip and the basal tooth- 
armature (flagellum reaching to the eye). 
a’. Flagellum taking its backward curvature some 
distance behind the tip of the upper fang ., Derbiana, Poe. 
6°, Flagellum taking its backward curvature close 
to the tip of the fang. 
a‘. Upper fang stout, nearly parallel-sided, 
distinctly toothed apically ; the flagellum 
lying close to its upper edge ............ Marshall, Poe, 
b*. Upper fang slender, concave above, scarcely 
toothed apically; flagellum rising high 
above'lts’ upper edges. ..cWustele ws, os cle hostilis, White. 
67, Upper fang continuously toothed from base to 
apex, strong. 
a’, Flagellum short, stout, apically truncate, 
scarcely surpassing lamina................ paludicola, Poe. 
b°. Flagellum long or short, but slender and api- 
cally pointed. 
a’. Flagellum distinctly serrated, of medium 
length. 
a’. Flagellum curving abruptly backwards 
close to the basal lamina, sinuous only at 
CLP oie ois cies aha ule cina's See meee ete Keyserlingit, Poe. 
* The males may be always distinguished from the females by the 
presence on the upperside of the mandible of that curious horny organ of 
unknown function called the flagellum. They also have longer legs, 
smaller mandibles, &c. 
i 
