A Monograph of the Formicidae of South Africa. 203 



Tribe SOLENOPSIDINI, Forel. 

 Sub-Tribe MONOMORIINI, Emery. 



The tribe includes the following South African genera: Monomorium, 

 Diplomorium and Solenopsis. 



Genus MONOMORIUM, Mayr. 

 Verh. Zool. Bot. Ges. Wien, vol. v, p. 452, 1855. 



Characters. 



£' . Head more or less rectangular ; mandibles narrow, with 3 or 4 

 acute teeth ; clypeus with the anterior margin more or less raised and 

 projecting over the base of the closed mandibles ; the triangular or 

 quadrangular median area is raised above the level of the short lateral 

 portions, and has usually two obtuse carinae, convergent behind between 

 the bases of the antennae (see Plate V, fig. 58c) ; sometimes the carinae 

 end in front in very short blunt teeth ; frontal area, distinct. Frontal 

 carinae short. Antennae 11- or 12-jointed, with a distinct club formed 

 of the three apical joints. Thorax widest in front ; promesonotal 

 suture obsolete, meso-epinotal suture deep and well defined. Epinotum 

 without teeth. First joint of petiole shortly pedunculate in front. 

 Abdomen distinctly, but not widely truncate at the base (see Plate V, 

 fig. 58a). 



$ . Thorax elongate, pronotum very little exposed above ; meso- 

 notum longer than wide ; dorsum of scutellum level or nearly so with 

 that of the mesonotum. Epinotum without teeth ; the declivity and 

 the posterior portion of the dorsum more or less excavated and concave, 

 so that the lateral margins appear raised or tumid. Petiole similar 

 to that of the £ • Abdomen elongate, rounded apically. Wings with 

 one cubital cell, the radial cell open. 



<§ . Head broad and flat ; eyes large, ocelli not large. Mandibles 

 well developed and dentate. Clypeus broad. Antennae filiform, 

 13-jointed. Thorax similar to that of the ? . Petiole, especially 

 the peduncle of the 1st joint, wider than in the ? , the node not so 

 high. Abdomen as in the ? , but with the basal angles rounded. 



This very large genus occurs in both hemispheres, chiefly in the 

 tropical zone, and includes several cosmopolitan species, some of 

 which are frequently found in hot-houses in temperate countries. 



