710 Transactions South African Philosophical Society, [vol. xii. 



of the pygidium, the segments are very compressed underneath and 

 soldered, in the female the abdomen is convex; the anterior tibiae are 

 tri-dentate {Hctcrochelus) or quadri-dentate (Isclniochelus) ; in the 

 first gi'oup the two basal teeth are either connate at the base or set 

 very close to each other, at right angles to the tibia, very sharp, 

 long, and almost always distinctly bending downwards, and the 

 apical tooth is more oblique than the other two and assumes the 

 same shape, there is occasionally a distinct angle above the basal 

 tooth, and in Ischnochelus this angle has been developed into a tooth 

 often nearly the same shape and size as the basal one, but in 

 I. bi-iMvtitus this tooth, although very distinct, is broader and more 

 triangular than the one following, there is no inner spur in either 

 sex ; the claws of the fore legs are doul)le, unequal, and the longer 

 one is always cleft, that of the intermediate legs is in most cases 

 double and both sides are cleft, but in several cases the smaller 

 inner one has disappeared (iJ. lugens, &c.), those of the hind legs 

 are either double with the inner claw always smaller than the 

 outer, pressed against it, and cleft, the larger one being cleft or not, 

 or single and simple, or cleft ; the difference in the shape of the 

 claws has no generic value whatever, but is very useful in discrimi- 

 nating between many species ; the intermediate tibiae have an apical 

 spur, and the posterior ones have one or are without ; when the 

 mucronate part of the hind tibiae of the male is very greatly 

 developed, this spur disappears completely, but there are exceptions 

 (H. femoralis, tmguiculatus, chiragricus, padagricus, insignis, &c.) ; 

 in the female this spur is always present ; in the male the hind 

 femora are very robust, or robust, seldom slender {iiubilus, dissidcns), 

 in some species of the division IscJinochelus armed with a long spine on 

 the trochanters or not, and sometimes with an inward tooth near the 

 knee, the tibiae are generally curved, hollowed underneath, carinate 

 or compressed, in most cases serrate or dentate, strongly mucronate 

 at apex or not, the articulation of the knee of the femur may be 

 developed into an angular process turning sometimes into a spine, in 

 this case the basal part of the tibia; is more or less deeply emarginate 

 or incised inwardly, and when it is scooped underneath, there is close 

 to that emai'gination or semicircular impression, a more or less sharp 

 tooth either on each side or on one side only. The female has a 

 more modest livery than the male, the hind legs are simple or not 

 unduly thickened ; whenever they have scales these are more like 

 squamose hairs, but there are some exceptions. 



The genus, as now restricted, includes 94 species, 10 of which I 

 have not been able to identify ; of these one does probably not 

 belong to the genus. 



