264 Mr. E-. 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. 

 rt^. Flagellum long, slender, simple, extending past 



the ocular tubercle ; protarsus of palp fuscous . . dentatidens, Sim. 

 i'. Flagellum short, stout, toothed internally near 

 the slender apex, which scarcely surpasses the 



basal lamina ; palp wholly ochraceous ferox, Poc. 



ft. Upper 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, Poc. 

 i'. 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 Marshalli, Poc. 



ft*. Upper fang slender, concave above, scarcely 

 toothed apically ; flagellum rising high 



above its upper edge IwstUis, White. 



ft^. Upper fang continuously toothed from base to 

 apex, strong. 

 a'. Flagellum short, stout, apically truncate, 



scarcely surpassing lamina j^aludicola, Poc. 



ft'. 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 

 tip Keyserlingii, Poc. 



* 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 Jlagelluni. Thej' also have Ljnger legs, 

 smaller mandibles, tSrc. 



