A Monograph of the Formicidae of South Africa. 115 



(8). 9. Sub-apical tooth of mandibles double, or truncate. 5 max. 8 mm. long. 



Rhogmus, Shuckard. 

 (3). 10. Antennae 9-jointed A laopone, Emery. 



9 ?. 



(2). 1. Antennae 12-jointed Ditcht hadia, Gerst. 



(1). 2. Antennae 11-jointed. 



(4). 3. Hypopygium in the form of a cleft plate, narrowed behind. 



Dorylus, Anomma, and Rhogmus. 

 (3). 4. Hypopygium wide, forming two lobes, divergent behind. 



Alaopone, Emery. 



$ <?• 

 (2). 1. Mandibles wide at the base and prolonged into a point, with the inner 



margin deeply excised Dichthadia, Gerst. 



(1). 2. Mandibles otherwise formed. 



(6). 3. Petiole wider than long, the posterior face concavely excavated. 



(5). 4. Mandibles less than 4 times as long as wide Dorylus, Fabr. 



(4). 5. Mandibles more than 4 times as long as wide. . .. Anomma, Shuckard. 

 (3). 6. Petiole nearly square, or round. 



(8). 7. Mandibles about three times longer than wide . . Typhlopone, Westw. 

 (7). 8. Mandibles much shorter. 



(10). 9. Wings with a 2nd recurrent nervure Rhogmus, Shuckard. 



(6). 10. Wings without a 2nd recurrent nervure Alaopone, Emery. 



The sub-genus Dichthadia is confined to Burma and the Malay 

 Archipelago. Dorylus, Anomma, and Rhogmus are entirely African ; 

 Alaopone and Typhlopone are almost entirely confined to Africa, but 

 have one species each in the Asiatic region. 



In the South African region, Anomma is apparently absent, 

 although it might be expected to occur on the East Coast from 

 Beira to Delagoa Bay. 



Sub-Genus DORYLUS, Fabr. (sensu stricto). 

 Ent. Syst., vol. 2, p. 194, 1793. Emery, Zool. Jahrb. Syst., vol. 8, 



p. 701, 1895. 

 Key to the % % and % 1/ of the Sub-Genus Dorylus. 



(2). 1. Sides of the head distinctly convergent posteriorly; puncturation of the 

 vertex of the head rather sparse and shallow, the sides of the head in 

 the smallest $ 5 quite smooth braunsi, Emery. 



(1). 2. Sides of the head not distinctly convergent posteriorly. 



(4). 3. Sides of the head almost parallel in the 2/ ; puncturation of the vertex 

 stronger and more abundant helvolus, Linn. 



(3). 4. Sides of the head less parallel in the %, the head being slightly narrower 

 behind than in front ; puncturation of the vertex sparser and feebler. 



{6). 5. Petiole not much wider behind than in front ; maximum length 11 mm. 



affinis, Shuckard. 



(5). 6. Petiole wider posteriorly ; maximum length 8*5 mm. . . brevipennis, Emery. 

 5 unknown furcatus, Gerst. 



