160 Annals of the South African Museum. 



$ . Antennae 13-jointed. Clypeus, frontal carinae, mandibles, 

 petiole, and abdomen more or less like those of the $ . Mavrian 

 furrows present. Subgenital plate rounded. Wings with one closed 

 cubital cell; no discoidal cell. 



Nymphs without cocoons in D. ocidata, Emery. 



Distribution. North America and the tropical regions of both 

 hemispheres. 



This genus can be distinguished from Sysphincta and Probolomyrmex, 

 and also from the new genus described further on, by the 9-jointed 

 antennae. 



D. Hewitti, n. sp. 



? . 2 '2 mm. Reddish ochreous, the occipital margin of the head, 

 the thorax and petiole darker or more brownish red. Dull, micro- 

 scopically coriaceous-punctate ; 2nd abdominal segment slightly shining 

 and fairly smooth. Clothed with a fairly dense but exceedingly fine 

 and short pubescence. Head very convex in its posterior half, one- 

 fifth longer than wide, wider behind than in front, the sides feebly 

 convex, the posterior margin straight or slightly concave. Clypeus of 

 the shape usual to the genus, being produced in front into a horizontal 

 shelf, hiding the mandibles, the anterior margin convex. Frontal 

 carinae fused into a single triangular plate, the front edge of which is 

 perpendicular to the plane of the clypeus and feebly convex, the dorsal 

 edge (when seen from the side) straight and horizontal, not extending 

 beyond the anterior fifth of the head. Mandibles triangular, with 

 a sharp tooth at the apex. Eyes large, convex, placed a little in front 

 of the middle of the sides ; ocelli small, placed at the angles of an 

 equilateral triangle. Antennae 9-jointed, the scape strongly dilated 

 apically, its apical width being nearly one-third of its length. First 

 joint of flagellum as long as wide, 2nd — 6th joints much wider than 

 long, the apical joint ovoid, pointed, twice as long as wide, longer than 

 the rest of the flagellum. Pronotum widely exposed above at the 

 sides, very little in the middle, the anterior angles rounded, the sides 

 parallel. Mesonotum moderately convex above, longer than wide, the 

 scutellum convex behind. Dorsum of epinotum very short, almost 

 parallel-sided, or only very slightly narrowed towards the apex, the 

 apical margin or brow of the declivity blackish, nearly straight, the 

 lateral corners rectangular but not dentate ; the declivity vertical, 

 submarginate. Petiole nodiform, transverse, twice as wide as long, 

 feebly convex above, sharply truncate in front, the anterior face 

 vertical ; the ventral lamella produced in front into an oblong and 



