418 Annals of the South African Museum. 



(B) Prelli Group. 



1/ . Head less convex than in Group A, the outline, seen from 

 above, not round but more or less quadrate ; the occipital sulcus deep 

 and continuous with the frontal sulcus. Sides of the head behind and 

 above the eyes sometimes fairly deeply and obliquely excavated (this 

 feature is much more distinct than in any member of Group A). 

 Frontal carinae prolonged back as far as the posterior third of the head, 

 or further. A trace of a scrobe present, and sometimes also of the 

 anterior ocellus. Second node angular at the sides, sometimes acutely 

 so, but not spinose. 



(4) 1. Whole head sculptured and dull ; occipital emargination not very 



deep. 

 (3) 2. Apices of the occipital lobes fairly angular ; head not parallel-sided ; 



scapes short . . . Prelli, race redbankensis, Forel. 



(2) 3. Apices of the occipital lobes rounded ; head parallel-sided ; the scapes 



long, extending to the posterior fifth of the head Maufei, Arnold. 



(1) 4. Occipital lobes smooth and shining, their apices strongly rounded; 



occipital emargination deep redbankensis var. politocciput, Santschi. 



(C) Allopheidole Group (subgenus Allopheidole, Forel). 



% . More or less like Group B in the shape of the head of the %, 

 but having forms intergrading between the 1/ and $ ; some of these 

 have the head wider in front than behind. Second node dentate or 

 nearly spinose at the sides 



cuitensis, Forel, race reddersburgensis, Forel. 



(D) Arnoldi Group. 



Small species, especially in the £ caste. 



1/ . Head longer than wide, slightly wider in front than behind 

 and nearly parallel- sided, or the sides only feebly convex ; the occipital 

 emargination fairly deep. Posterior two-thirds of the head smooth 

 and shining. Second node of petiole sharply spinose at the sides, the 

 spines curved a little backwards or sharply angular. 



(2) 1. 2/. . Head a little more than a quarter longer than wide ; $ , head and 



thorax dull ...... Arnoldi, Forel. 



(1) 2. It-. Head at least two-fifths longer than wide; $, head and pro- 

 notum shining . . . strator, Forel, race fugax, Arnold. 



(E) Capensis Group. 



% . Yery similar to Group D, but the posterior emargination of 

 the head is less deep and less angular. The head is longer than wide, 

 not wider in front than behind, almost parallel-sided. Second node 



