578 Annals of the South African Museum. 



Amatongas Forest, Portuguese E. A. (SA.M., R.M., GA. colls. ; 

 types in my collection.) 



Nesting in a decayed tree-stump in the shadiest part of the forest. 

 This species is unlike any other of the genus known to me. The 

 remarkably deep impressions in front and behind the metanotum and 

 the peculiar shape of the epinotum are very distinctive. 



Genus PLAGIOLEPIS, Mayr. 



Europ. Eormicid., p. 42, 1861. 

 Characters. 

 $ . Sometimes polymorphic, the forms differing chiefly in size, 

 very little in structure. Antennae 11 "-jointed, without a club. Scape 

 as long as the head or longer. Clypeus large. Frontal carinae short; 

 frontal area not well defined. Traces of the ocelli are present. Pro- 

 notum and epinotum large, usually much wider than the rest of the 

 thorax. Pro-mesonotal suture distinct ; meso-metanotal and meta- 

 epinotal sutures more or less distinct. Epinotum unarmed. Scale 

 of petiole usually inclined forwards, without a peduncle or with only 

 a very short one. 



9 . Antennae ll*-jointed. Thorax similar to that of Acantlwlepis 

 $ , but broader and shorter. Petiole as in the 9 ■ Abdomen usually 

 very massive. Wings with a closed radial and one cubital cell ; 

 discoidal cell absent 



$ . Antennae 12-jointed, the scape at least half as long as the 

 flagellum. Genital armature large and exserted. 

 Distribution. — Both hemispheres. 



The genus may be divided into the following sub-genera : 



(4) 1. Metanotum distinctly defined in front and behind. 



(3) 2. $ . Metanotum vexy prominent, separated from the short and convex 



epinotum by a deep suture ; the epinotum higher than the meta- 



netum. Rarely polymorphic (a sub-genus transitional to the 



genus Acantholepis) . . Sub-genus Anacantholepis, Santschi. 



(2) 3. § . Metanotum not prominent ; meta-epinotal suture usually feeble ; 



epinotum oblique, not higher or not much higher than the 



metanotum. Small species, not polymorphic. 



$ . Not much larger than the $ , but considerably larger than the $ . 



$ . Scapes not much longer than the head, the latter wider than long. 



Sub-genus Plagiolepis, Mayr, s. str. 

 (1) 4. Metanotum indistinctly defined or almost obsolete. 



(6) 5. £ . Metanotum small, much smaller than the mesonotum, from which 

 it is feebly delimited ; epinotum convex and higher than the 

 metanotum. Large species, often polymorphic. 

 $ . Not very much larger than the $ major or the $ . 



