A Monograph of the Formicidae of South Africa. 555 



Epinotum always rather large and somewhat inflated, armed with 

 a tooth or spine on each side or simply bituberculate, often excavated 

 longitudinally above, and sometimes more or less emarginate between 

 the teeth or tubercles. The dorsum of the epinotum higher than 

 the meso- and metanotum. Petiole with a more or less scale-like 

 node anteriorly and a peduncle behind, the scale emarginate, or 

 bidentate or bispinose above. Abdomen oval, acute apically. Legs 

 long and slender. 



9 . Not considerably larger than the £ . Ocelli not large. Pronotum 

 not visible from above. Mesonotum broad, the scutellum much 

 wider than long, its posterior margin wide and not angular. Meta- 

 thorax fairly evident. Epinotum lower than the anterior part of the 

 thorax, unarmed. Scale of petiole round or pentagonal, unarmed or 

 merely emarginate above. Abdomen massive. Wings long, extending 

 beyond the apex of the abdomen ; anterior wing Avith 1 cubital cell, the 

 radial cell closed. 



$ . Much smaller than the ?. Antennae 12-jointed ; the scape 

 long, at least half as long as the flagellum. Head more or less 

 triangular, eyes large, ocelli small. Pronotum not visible from 

 above. Scutellum narrower behind than in the £ > the posterior 

 outline more or less conical, much higher than the epinotum. The 

 latter unarmed. Scale of petiole thicker than in the $ . Wings long, 

 but yet shorter and wider than in the $ . 



Distribution. — Palaearctic, Ethiopian and Indo-Malayan regions. 



The members of this genus are very active insects. All our species 

 fonn their nests in the ground, usually under stones. The colonies 

 are of moderate size, nests containing more than about 200 £ £ 

 being rare. I have no records of myrmecophilous insects having been 

 found in the nests of any of our South African species. Most of them 

 are omnivorous, with a partiality for sweet substances, and therefore 

 aphidicolous. 



V 

 Key to the Species of Acantholepis ^ £ . 



(10) 1. Node of petiole bispinose above, the spines as long as or longer than 



the node is wide. 

 (5) 2. Petiole very long, two and a-half times as long as the node is high 



(excluding the spines) ; the spines long, thin and straight. 

 (4) 3. Head and thorax reddish -brown, dull and reticulate-punctate 



longinoda, Arnold. 

 (3) -i. Head and thorax ochreous, smooth and shining . arcnaria, Arnold. 

 (2) 5. Petiole shorter, as lung as, or very little longer than the node is high. 

 (9) 6. Spines of node round in cross- section, thicker at the base than at the 



apex. 



