148 Annals of the South African Museum. 



the keel punctured ; the punctures long, clearly separated ; the 

 middle closely, transversely striated ; the apex almost smooth, 

 bounded above by a semicircular keel. Upper half of propleurae 

 smooth, the base narrowly and the lower half closely, finely striated. 

 Mesopleurae finely, closely reticulated, more or less striated at the 

 base. Metapleurae more strongly but quite as closely reticulated as 

 the mesopleurae. Abdomen shining, dilated and compressed late- 

 rally towards the apex. 



The parapsidal furrows are deep ; the thorax is three times longer 

 than wide ; the metanotum has a gradually rounded slope and is 

 without teeth. 



Mesostenus levifrons, sp. nov. 

 Length 17 mm. ; terebra 25 mm. 



This species closely resembles M. lissonotus, from which it may 

 be separated as follows : — 



Clypeus and palpi white ; the former not bordered laterally by a 

 deep furrow ; base of mandibles marked with white ; breast and 



upper side of pleurae black levifrons. 



Clypeus and palpi black ; the former bordered laterally by a 



furrow ; base of mandibles black ; breast and pleurae red . . . . lissoiiotit-t. 



Black ; the clypeus, labrum, palpi, the apices of the first and 

 second abdominal segments, of the third, fourth, and fifth more 

 narrowly, in the centre ; the apical half of the sixth and the whole 

 of the seventh, white. Four front legs testaceous, their coxae black ; 

 the under side of the femora black; the basal joint of the tro- 

 chanters white. Wings hyaline, the nervures and stigma black, 

 the small areolet square, receiving the recurrent nervure near the 

 middle, the transverse median nervure behind the basal. ? . 



Length 17 mm. ; terebra 27 mm. 



Natal. Durban. 



Front and vertex smooth, except for a few punctures on the sides ; 

 face closely rugosely punctured, except for a large semicircular 

 space on the sides, the narrowed rounded part on the inner side. 

 Clypeus and labrum smooth, shining. Mesonotum shining, im- 

 punctate, the furrows crenulated. Scutellum strongly, sparsely 

 punctured. On the centre of the basal region of the metanotum 

 are two strongly, but not closely, punctured areae ; the rest is 

 closely, transversely striated ; the base more closely and irregularly 

 than the apex. Propleurae smooth, except for a striated, curved 

 band in the centre. Mesopleurae closely strongly punctured, more 

 or less reticulated ; on the upper apical half are two large, longish 



