26 Transactions South African Pliilosojjliical Society. [vol. xii. 



nate between species very closely allied to one another. Although 

 very distinct in some groups, in others the difference is not great, 

 but that small difference is strengthened by the habitat. Thus in 

 S. metallicus and S. usurpator the facies, as well as the colour, are 

 very similar, but the genital armature differs very much-; in 

 S. honcllii and in S. clcricus the difference between the two genital 

 armatures is very feeble, and the general appearance is nearly 

 similar, but S. clcricus does not occur in the Cape Colony, except on 

 the northern border (Griqualand West), nor in Natal, as far as I 

 know, and I am somewhat inclined to consider it as a mere variety 

 of the former. I have also examined the clasping organs of some of 

 the convex, metallic African species from the West Coast, Abyssinia, 

 &c., and the shape of the valves is certainly distinct, although speci- 

 fically different from that of the other groups. 



Key to the Sub-genera. 



A-. Sheaths of the genital armature symmetrical. 



B-. Spurs of intermediate and posterior tibise fused with the leg. 



Anterior femora extremely large Pachylomera, 



A'. Sheaths of the genital armature asymmetrical. 



C'-^. Clypeus with the two median teeth not dentate vertically 



underneath Ateuchus. 



B^ Spurs of intermediate and posterior tibiee articulate. 



C^ Clypeus with the two median teeth dentate vertically 



underneath Sebasteos. 



Sub-Gen. PACHYLOMEEA, Kirby, 

 Zoolog. Journ., iii., 1828, p. 520. 



Pachylomeea femoralis, Kirby, 

 Plate XXXI., fig. 5, and Plate XXXVIL, fig. 1. 

 Zoolog. Journ., iii., p. 520, pi. xiv., fig. 1. 

 P. horridus, Bohem., Ins. Caffr., ii., p. 179. 



Black, moderately shining ; antennae piceous brown ; head finely 

 and distinctly granulose, but nearly smooth in the centre of the 

 vertex ; clypeus covered with very elongated and very closely set 

 punctures merging into one another, and forming striae, teeth of 

 the clypeus not very long, but acute, and not very much reflexed ; 

 prothorax little convex, distinctly bi-sinuate at the apex the angles of 

 which are sharp, very diagonal laterally from the anterior angle to 

 about the median part, lateral margin serrulate, basal margin still 

 more feebly serrulate, disk sub-opaque, finely granulate, and with 



