A Monograph of the Formicidae of fiouth Africa. 113 



V 

 Key to the Tribes of the Dorylinae. 



A. $ 2/. . Pygidium tridentate, with a median impression ; maxillary and labial 

 palpi 2-jointed ; cheeks without a longitudinal carina ; 1st abdominal segment 

 not separated from the 2nd by a constriction. 



? . Cloaca open, leaving the sting uncovered ; hypopygium forked and extending 

 considerably beyond the pygidium ; thorax unsegmented. 



$ . Stigma of anterior wing very elongate and narrow ; radial cell open and 

 elongate, one closed cubital cell; genital armature retractile. . Dorylini, Forel. 



B. 5 Tj. . Pygidium simple ; maxillary palpi 2- or 3-jointed, labial palpi 2-jointed ; 

 cheeks longitudinally carinate ; a constriction usually separates the 1st and 

 2nd abdominal segments, almost making the petiole 2-jointed. 



$ . Cloaca covered by the pygidium ; hypopygium not considerably extended. 

 $ . Stigma of wing very narrow ; radial cell elongate, one or two closed cubital 

 cells ; genital armature retractile Ecitini, Forel. 



C. $ • Pygidium simple ; maxillary and labial palpi 1-jointed ; cheeks not 

 carinate ; petiole 2-jointed. 



? . Cloaca open, leaving the sting uncovered ; hypopygium lobed and extending 

 beyond the pygidium ; thorax with a suture behind the anterior pair of legs, 



whichis effaced on the dorsum. 



cf . Anterior wings without stigma or nervures. Genital armature extended, 



not retractile Leptanillini, Emery. 



The Dorylini is the only tribe represented in South Africa ; it is 

 totally absent from America. The Ecitini, excepting Aenictus and 

 Aenictogeton, are confined to America, chiefly South America ; and 

 the Leptanillini have so far been found only in North Africa, Singa- 

 pore, Corsica, and Sardinia. The Tribe Dorylini comprises a single 

 genus Dorylus, Fabr., and is divided into six sub-genera. 



Genus DOEYLUS, Fabr. 

 Ent. Syst., vol. 2, p. 194, 1793. 

 Characters. 

 $ 1/ . Owing to the extreme polymorphism exhibited in this 

 genus no distinct line of demarcation can be drawn between the 

 g and the 1/ . The £ occurs in all sizes, the largest being regarded 

 as 3/ . Three chief types may, however, be distinguished, but con- 

 nected by intermediate forms. (In the descriptions of the species 

 only these three chief types will be dealt with in extenso.) 



1. Very large individuals or soldiers. 



In these the head is enormous, and wider or not less wide in 

 front than behind ; the mandibles have fewer teeth than in the £ ; 

 the clypeus is not very protuberant ; the antennal joints are of the 

 normal number, 9 to 12 according to the species. 



2. Medium-sized individuals or large workers. 



