134 Annals of the South African Museum. 



pair are near together and parallel in the new variety, whereas 

 they are clearly divergent behind in the type. Moreover, each is 

 obliquely truncated, so that the medial angle of its posterior extremity 

 is acute and pointed. Otherwise like the type, but a little smaller. 

 Orange Free State." 



D. (Sub-G. Alaopone) diadema, Gerstaecker. 



Monatsb. Akad. Wiss. Berlin, p. 261, $ , 1858. Forel, Ann. S. E. 

 Belg., vol. 43, p, 309, $ , 1899. 



Gerstaecker's description of the species is so short as to be useless ; 

 a more complete one has been made by Forel, which is as follows. 



" $ . 20-20*3 mm. The compound eyes are nearly smooth, the 

 facets not forming separate convexities. Width of the head with the 

 eyes, 3 - 3 mm. ; length of the head without the mandibles, 1*9 mm. ; 

 maximum width of the thorax, 3 mm. ; maximum width of the abdo- 

 men, 3 mm. ; width of the petiole 2-1 mm., length 2 mm. ; length 

 of anterior wing 15 5 mm. 



Elongated like juvenculus (= fulvus). Mandibles thick, short, 

 bevelled at the apex, smooth and shining. Labrum entire, as in 

 helvolus and nigricans (bilobed in juvenculus). Mutual distance of 

 the posterior ocelli a little greater than their distance from the 

 compound eyes. The ocelli are not very large, much smaller than 

 the interval which separates the posterior ones from each other. 

 The frons gibbous, the frontal sinus of the usual shape, and extending 

 from the frontal area to the anterior ocellus, without forming a deep 

 impressed line such as is seen in juvenculus. The clypeus also is 

 not sunken as in that species. Thorax fairly strongly narrowed 

 behind, more so than in juvenculus. Petiole cubic and rounded, 

 a little widened posteriorly, where it is wider than it is long, but the 

 width in front is hardly equal to its length. Abdomen narrow and 

 elongate, but slightly curved, as in juvenculus. The femora are 

 widely dilated and flattened up to the tibial articulation, which is 

 barely narrowed and not in the least rounded or thickened, as is 

 the case in the other species. The femora are also shorter, being 

 but a trifle longer than the coxae. The scape is barely longer than 

 the first 4 joints of the flagellum. 



The head is closely punctured and dull, except the frontal area, 

 which is smooth and shining ; the space between the punctures does 

 not appear quite smooth. The thorax, petiole and abdomen are 

 abundantly punctured and sub-nitidulous, the thorax is more shining 

 than the petiole and abdomen. On the latter the punctures are 

 fairly close, but without forming reticulations. The last abdominal 



