562 Transactions South African Plnlosoijliical Society, [vol. xii. 



the base to a third of the length, emarginate there and sHghtly 

 attenuate towards the apex where it is very deeply sinuate in the 

 outer angles, and bi-lobate at the apex ; it is not very convex in the 

 median part, but is deeply impressed at apex ; maxillae with the upper 

 lobe armed with two sharp teeth bent at right angles, the upper of 

 which is a little concave and placed above the second one which is not 

 hollowed and is set on the inner margin and a little below the first, 

 and below these the inner lobe is produced into a trifid, transverse 

 tooth; palpi and mandibles as in Rhizoplatys, but the mandibles are 

 more aculeate and produced at apex into a triangular reflexed tooth. 



Ehizoplatodes castaneipennis, Bohem., . 

 Insect. Caffrar., ii., p. 27. 



Rhizoplatys ambiguus, Gerst., Deck. Eeis., p. 873, p. 105, pi. vii., 

 fig. 2. 



Head and prothorax piceous black ; elytra either piceous black or 



chestnut-brown, legs piceous red ; head very rugose ; clypeus very 



obliquely attenuate laterally, and with the apical part triangular and 



reflexed ; in the male the posterior part of the head is deeply 



excavate in the middle, and there is, close to the apex of the 



clypeus, a conspicuous, vertical tooth, hooked backwards at tip 



and about 2 mm. long ; in the female there is a similar impression, 



but much more shallow, the dentate apex of the clypeus is prolonged 



towards the median part in a short, high carina, connected often 



with a sharp tubercle situated in the centre of the head ; prothorax 



briefly retuse in front in the male, the retuse part being divided 



nearly into two by a triangular, narrow longitudinal impression 



which is continued as a deep furrow along the discoidal part as 



far as the base ; in the female the anterior part is not retuse, and 



tlie impression is more in the shape of a groove, also continued as 



far as the base ; in both sexes the surface is covered with round 



punctures a little remote in the posterior part and denser and a little 



deeper in the anterior and lateral parts ; scutellum punctate in the 



base and centres elytra elongate, somewhat plane, nearly parallel, 



declivous at apex, covered with shallow, slightly cicatricose 



punctures closely set, and with the striae obliterated ; pygidium 



moderately closely punctate in the male, rugose in the female ; 



abdominal segments with one median row of setigerous punctures, 



but the apical one is smooth in the centre in the male ; this segment 



is very rugose, and the others closely punctured, as well as having 



