84 Annals of the South African Museum. 



some comparisons made between this race and some extra-ethiopian 

 species. 



Genus PLECTKOCTENA, Smith 



Cat. Hymen. Brit. Mus , vol. 6, p. 101, 1858. 



Characters. 



$ . Clypeus very narrow, anterior margin straight, except above 

 the base of the mandibles where it is shallowly emarginate ; labrum 

 very large. Mandibles long and narrow, with a deep sulcus from 

 base to apex on the upper inner side ; one large tooth below the- 

 middle, and a small and very obtuse one between that and the apex ; 

 the latter is obtuse. Frontal carinae large, slightly convergent 

 behind, overhanging and apparently fused with the clypeus in front. 

 Antennae incrassate gradually towards the apex. Eyes small, 

 placed far forwards close to the base of the mandibles. Head much 

 wider than the thorax. Thorax large, pro-mesonotal suture wide 

 and deep, meso-epinotal suture slight or obsolete. Declivity of 

 epinotum with the lateral margins raised into strong ridges. Con- 

 striction between the 1st and 2nd abdominal segments strong. 

 Node of petiole thick, longer than broad. Inner calcar of middle 

 and hind legs well developed, outer calcar absent. 



? . A winged ? is not known in manclibularis ; in subterranea r 

 Arnold, and minor, Emery, winged ? ? occur which are very 

 similar to the £ . 



$ . Clypeus triangular ; frontal carinae well developed but short 

 and considerably raised. Antennae long, reaching back as far as 

 the base of the 2nd abdominal segment ; scape less than half tbe 

 length of the 2nd joint of the flagellum, 1st joint of the latter very 

 short, only one-third the length of the scape. Eyes moderately 

 large, occupying less than half the sides of the head ; ocelli not. 

 situated on a raised area. Pronotum exposed ; Mayrian furrows on 

 the mesonotum strongly marked ; scutellum raised, pyramidal and 

 grooved longitudinally. Declivity of epinotum with raised lateral 

 ridges as in the £ . Node of petiole higher than long. Abdominal 

 constriction distinct. Pygidium bluntly pointed. 



P. subterranea, n. sp. (Plate III., figs. 23, 23a.) 



$ . 7 - 5 mm. Castaneous red ; all the joints of the flagellum, 



except tbe apical, reddish brown. Except in size, puncturation, 



colour, and dimensions of the eyes, this species is very similar to 



mandibularis. Pubescence entirely wanting except on the legs and 



