194 Annals of the South African Museum. 



Tribe OCYMYEMICINI, Emery. 



Genus OCYMYRMEX, Emery. 

 Bull. Soc. Ent. Ital., vol. 18, p. 363, 1886. 



Characters. 



$ . Head sub-quadrate. Clypeus convex, the anterior margin 

 rendered more or less bidentate by a median excision. Frontal area 

 narrow, distinct. Antennae 12-jointed, nearly filiform, scape long, at 

 least half as long as the flagellum. Mandibles, clypeus and head 

 below the mouth furnished with long curved hairs (ammochaetae). 

 Thoracic sutures absent ; thorax unarmed, depressed in the middle. 

 First joint of petiole pedunculate, the peduncle very thin and longer 

 than the node ; 2nd joint more or less barrel-shaped. Abdomen 

 small, more or less pyriform, legs very long and slender. ? un- 

 known. 



$ . Antennae filiform, 13-jointed, the scape very short, not more 

 than twice the length of one ocellus ; 1st joint of flagellum very short, 

 half the length of the scape, the remaining joints all at least three 

 times longer than wide. Eyes and ocelli large, the latter on a raised 

 area. Mesonotum very wide and gibbous, overhanging the pronotum. 

 Scutellum gibbous. Mayrian furrows and parapsidal sutures absent. 

 Wings with one closed cubital cell, the discoidal cell absent, the radial 

 short. 



The ants of this genus live in hot, arid and sandy localities. The 

 nest, usually made in loose sandy soil, is surmounted by a crateri- 

 form mass of earthen or sandy pellets derived from the excavation of 

 the underground galleries. The entrance is always central, at the 

 bottom of the crater. Like other aremphilous ants, the species of this 

 genus possess long curved hairs or " ammochaetae," fringing the 

 mandibles, clypeus, and the ventral surface of the head behind the 

 mouth. The hairs, forming a sort of basket around the mandibles, 

 facilitate the l'emoval of grains of sand in the excavation of their 

 nests. These ants are also endowed with the most marvellous 

 celerity, far excelling in this respect all other ants with which I am 

 acquainted, so much so that they appear almost to fly over the surface 

 of the ground. Their motion is just as erratic as it is swift ; they 

 seem incapable of pursuing a straight path for more than a couple of 

 inches, and watching one of these insects for but a short time, a 

 casual observer might be led to suppose that the unfortunate animal, 

 having lost its way, had been seized with hysterical dementia. The 



