372 Transactions South African Philosophical Society, [vol. xiii. 



D 1 . Clypeus carinate laterally, the angles sharply 

 angular or projecting considerably beyond the 

 anterior margin Diplognathii. 



a. Maxillae strongly dentate. 



Anterior angles of clypeus very sharply 

 angular ; elytra neither costate nor striate ; 

 sternal process acuminate Diplognatlui. 



Anterior angles of clypeus projecting far 

 beyond the anterior margin ; elytra pluri- 

 costate, sternal process strongly aculeate. . Apocnosis. 



Gkoup ISCHNOSTOMII. 

 This Group includes soberly clad insects, differing from the 

 Ceratorrhinii in the absence of a long projecting sternal process, 

 the metasternum merely penetrating the apex of the intermediate 

 coxae, or bluntly triangular there ; the shape of the clypeus is very 

 singular in some of the males, in which sex the antennal club is 

 much longer than in the female, and in some cases (Gariep) as 

 much developed as in any South African Pachypodin/i. The very 

 strongly spatulated shape of the upper spur of the hind tibiae in 

 the 2 plainly implies a mode of life akin to the representatives of 

 that Sub-Family. That in the adult stage they feed only on semi- 

 liquid matter is proved by the shape of the maxillae. Except for one 

 species met with in Central Africa, representatives of this Group are, 

 so far as now known, restricted to South Africa. 



Gen. ISCHNOSTOMA, Gory and Percheron, 



Monogr. d. Cet., 1833, p. 42. 



Mentum ovoid, concave, ligular part parallel, nearly half the 

 length of the mentum, scooped laterally along almost its whole 

 length for the reception of the labial palpi which are inserted at 

 the apex, and sub-arcuate in front ; labial palps as long as the 

 three apical maxillary ; maxillae very slender, upper lobe very 

 narrow, twice as long as broad, and with a long pencil of black 

 hairs at tip; maxillary palps extremely long; the mentum and 

 maxillae are clothed with very long, black hairs; clypeus of J 

 longer than the head and differently shaped, that of the $ very 

 elongated, deeply emarginate at apex, canthus of the eyes horizontal 

 and spinose ; antennae long, club as long or longer than the pedicel 

 and laminiform in the $ , shorter and oblong in the $ ; prothorax of 

 the S diagonally attenuate laterally in front, straight from near the 



