64 Annals of the South African Museum. 



The genus is divided into four sub-genera as follows : — 



Key to the £ $ of the Sub-Genera o/Euponera. 



(2). 1. Mandibles elongate, the masticatory margin long, with numerous teeth ; 1st 

 joint of flagellum usually shorter or of the same length as the following, 

 rarely longer Mesoponera, Emery. 



(1). 2. Mandibles rather short, with few teeth ; 1st joint of flagellum much longer 

 than the 2nd. 



(4). 3. Length 9-10 mm. ; mandibles with 8 teeth ; Madagascan species. 



Euponera, Forel. 



(3). 4. Insect much smaller. 



(6). 5. Mesonotum gibbous ; surrounded by a deep suture ; 1st joint of tarsi of the 

 middle pair of legs not bristly on the dorsal surface. Brachyponera, Emery. 



(5). 6. Mesonotum depressed, the surrounding suture not deep ; tarsi of the middle 

 pair of legs short, and bristly on the dorsal surface. 



Trachymesopus, Emery. 



Sub-Genus MESOPONEEA, Emery. 

 Ann. Soc. Ent. Belg., vol. 45, p. 43, 1901. 



Characters. 



$ . Clypeus rounded, rarely pointed on the anterior margin. 

 Mandibles elongate, with numerous teeth. Maxillary palpi 4-jointed. 

 1st joint of flagellum shorter or of the same length as the 2nd, rarely 

 longer. Thorax generally elongate ; mesonotum more or less oval 

 and surrounded by a suture ; dorsum of epinotum in the elongate 

 species equal in length to the pro- and mesonotum together. Legs, 

 and especially the tarsi of the middle pair, long and slender, the tarsi 

 rarely bristly. 



5 . As in the g . 



3 . Emery remarks (" Genera Insectorum ") that he knows of no 

 character sufficient to distinguish the $ $ of this sub-genus from 

 those of Pachycondyla. 



Key to the % % of Mesoponera. 



(6). 1. Large species, more than 6 mm. long. 



(3). 2. Insect 9 mm. long, whole body dull caffraria, Smith. 



(2). 3. Longer than 9 mm., at least the greater part of the body shining. 



(5). 4. 10-5 mm. long, head duller than the thorax and abdomen, fovea on the 



mandibles shallow and transverse Peringueyi, Emery. 



(4). 5. 11-13 mm. long, head not duller than the thorax and abdomen, fovea on the 



mandibles deep, sharply defined and oblique Havilandi, Forel. 



(1). 6. Small species, less than 6 mm. long. 



(8). 7. Colour black or nearly so fossigera, Mayi*. 



(7). 8. Colour brown or yellowish brown . . Elizae, Forel, var. rotundata, Emery. 



