1900.] Catalogue of I he Colcoptera of South Africa. 521 



Hetcronychits ; instead of being regularly convex in the median part, 

 it has an arcuate roiuided median ridge and a sub-vertical shghtly 

 depressed space underneath, the upper half is closely rugose, 

 and the lower half quite smooth, the fold is moderately broad 

 at middle, but not impressed ; intermediate abdominal segments 

 feebly punctate transversely ; metasternum not impressed. Female 

 unknown. 



Length 15^ mm. ; width 8 mm. 



Hah. Transvaal (Potchefstroom). 



Heteronychus tristis, Bohem., 

 Plate XL., fig.^ 7. 

 Insect. Caffrar., ii., p. 9. 



This species is the smallest Hctcronyclms known, and is as often 

 dark chestnut as black ; the clypeal and frontal carina? are similar to 

 those of H. indoiatus, but the clypeal one is a little flexed towards 

 the apex ; the scutellum has no impressed, median longitudinal line ; 

 the striae on the elytra are deep and the punctures very conspicu- 

 ous, the dorsal intervals are very slightly convex and impunctate 

 except in the basal part of the second ; the pygidium is normally 

 convex, the upper half very rugose and the lower one smooth ; inter- 

 mediate abdominal segments with rows of transverse setigerous 

 punctures of nearly equal length ; metasternum slightly impressed, 

 and with a distinct, median longitudinal line. 



Length 8^-9 mm. ; width 4f -5 mm. 



Hab. Natal (Durban, Estcourt), Mozambique (Lourenco-Mar- 

 quez). 



Heteronychus arator, Fabric, 



Plate XL., fig. 7: C. 



Entom. Syst., i., p. 33. 



H. cricetus, Hausm., Illig. Magaz., vi., p. 266, 1807. 



Black, shining ; head with the clypeal carina moderately distinctly 

 interrupted in the centre and the frontal carina sinuate in the 

 middle but entire, rugose and somewhat transversely plicate ; 

 prothorax nearly parallel for two-thirds of the length, and oblique, 

 but not arcuate in the anterior part ; scutellum sharply ogival ; elytra 

 distinctly ampliate laterally past the sinuate part, deeply punctato- 

 striate, with the five dorsal intervals impunctate, and a faint series 



