548 Transactions South African Philosoj^hical Society, [vol. xir. 



Gen. OEYCTES, Illig., 

 Kafer Preuss., 1798, p. 11. 



Mentum small, elongate, ampliate laterally above the base, slightly 

 attenuate from there and with the apical part oblong ; it is moderately 

 convex in the middle, but the apical part slopes backwards and 

 is moderately deeply excavate, labial palpi short, apical joint sub- 

 fusiform, rounded at tip ; maxillae not very robust for the size of the 

 insect, inner lobe horny, transverse, slightly concave, having a thick 

 fringe of long, ciliate hairs on the upper and outer margins, but none 

 inwardly ; maxillary palpi moderately long, second joint robust, 

 thicker and a little longer than the apical one which is fusiform 

 inwardly, straight and grooved outwardly, and moderately bluntly 

 rounded at tip ; mandibles triangular at tip, but with the inner part a 

 little arcuate, projecting a little beyond the clypeus which is broadly 

 incised and has two strong recurved teeth at apex, and densely ciliate 

 all round ; genae reduced to a lobate canthus ; head with a strong 

 triangular tooth in the frontal part, or a very long horn curving back- 

 wards, according to the sex, and also to the species ; prothorax 

 narrowed laterally in front, not very ampliate past the middle, 

 somewhat convex, and with the anterior part more or less deeply 

 excavated or impressed according to the sex ; scutellum somewhat 

 bluntly triangular ; elytra elongate, and with strias almost indistinct 

 or well defined, but always with a well-defined juxta-sutural one ;. 

 propygidium with the median part very finely plicate transversely ;. 

 pygidium narrow, transversely convex ; anterior tibiae pluri-dentate ; 

 anterior tarsi slender and similar in both sexes, claws simple, 

 onychium long and briefly penicillate, basal joint of posterior tarsi 

 produced into a long, sharp tooth ; abdominal segments not con- 

 tracted ; intercoxal ledge of prosternum plane beneath and truncate 

 at tip ; sternum densely pubescent, except the median part of the 

 metasternum. 



The most common of the two species found in South Africa is 

 0. boas, which is occasionally found in manure-heaps ; the second 

 species, 0. monocoros, is found in rotten trunks, and is consequently 

 limited to the eastern forest belt extending as far as Knysna in the 

 Cape Colony. 



Key to the Species. 

 X". Anterior tibiae tri-dentate and with a supra-digital tooth. 



Cephalic horn very long and curved, with the prothorax deeply excavate 

 and bi-tuberculate in the male ; cephalic horn short and vertical on the 

 female, anterior impression on prothorax, shallow and uni-tuberculate 

 at tip ; elytra obsoletely striate in both sexes boas. 



