A Monograph of the Formicidae of South Africa. 489 



must sink as a synonym of castanea, Smith, which antedates it ; it is 

 retained, however, as the sub-specific name of the form which occurs 

 in Madagascar and JSTatal. As far as I am aware the type-species is 

 not African. 



Race tricolor, G-erst. (Plate VI, figs. 72, 72 a). 



Monatsb. Akad. Wiss. Berlin,- p. 263, £, 1858. 

 Forel, Mitth. Schweiz. Ent. G-es., vol. 7, p. 388, $, <y, 1887. 



£' . 4'2-4"8 mm. Head, thorax and petiole varying from bright 

 yellowish-red to chestnut-red (burnt sienna), the 1st segment of the 

 abdomen varying from ochreous yellow to reddish ochreous over its 

 basal two-thirds, the whole of the remaining segments dark brown 

 with yellowish and somewhat translucent apical margins. Tibiae and 

 tarsi more or less brownish-red. Antennae coloured like the head but 

 somewhat fuscous on the club and on the basal half or two-thirds of 

 the scape. Pilosity almost entirely absent excepting a few short and 

 thin hairs on the pronotum and apical margins of the abdominal 

 segments. Pubescence very fine, microscopical, not very abundant, 

 decumbent all over except on the flagellum, where it is oblique and 

 longer than elsewhere. Head dull, very finely and closely rugulose 

 longitudinally, sometimes almost striato-rugulose ; the anterior corners, 

 between the antennal sockets and the eyes, distinctly striated obliquely. 

 The space between the frontal carinae is slightly shining, with the 

 sculpture somewhat effaced. Mandibles longitudinally striate, dull, 

 the masticatory margin black, armed with 4 or 5 sharp teeth. Thorax 

 dull, reticulate-rugulose, the sculpture on the epinotum becoming 

 progressively weaker, so that at least the lower half of the declivity is 

 smooth and shining. Occasionally there is a feeble longitudinal rugosity 

 superimposed on the pronotum and extreme base of the epinotum. 

 Petiole microscopically reticulate or alutaceous, dull except the upper 

 face of the 1st node, which has a slight gloss. Abdomen and legs 

 feebly shining, the former very finely alutaceous. 



Head rotund, a trifle longer than wide, the sides convex, the hind 

 angles widely rounded, the posterior margin very feebly concave in 

 the middle, or nearly straight. Anterior margin of the clypeus feebly 

 convex in the middle ; the median area fairly convex transversely and 

 lengthwise, its posterior margin arcuate and not clearly defined. 

 Frontal ai'ea triangular and indistinct. Behind it is a median 

 impressed line ending at the posterior third of the head. Scape as 

 long as the head, 1st joint of flagellum twice as long as wide, 3rd and 



