wheeler: the ants of borneo. 89 



single worker specimen. It is very small (2.2 mm.), ferruginous yellow, 

 with the spines more curved and more nearly horizontal than in the 

 other species. 



*105. ACANTHOMYRMEX DUSUN, Sp. nOV. 



Soldier. Length 3.6 mm. 



Head very large, extending back over the thorax to the mesoepinotal con- 

 ■striction, subrectangular, a httle longer than broad, with straight, parallel 

 sides in front and rounded posterior corners, or lobes, separated by an angular 

 occipital incision continuous with a deep occipital and frontal groove, running 

 forward to the clypeus. In profile the dorsal surface of the head is convex 

 and rounded, but distinctly depressed in the middle just in front of the occi- 

 pital border. Eyes small, elongate elliptical, rather convex, at the anterior 

 fourth of the sides. Clypeus, mandibles, and antennal scrobes shaped much 

 as in dyak, but the frontal carinae which border them much more diverging 

 behind and the frontal area obsolete. Antennae also very similar, but joints 

 2 and 3 more transverse and joints 4-8 as long as broad. Thorax short, the 

 epinotal spines very long, stout at the base, tapering and pointed at the tips, 

 strongly curved backward and downward and somewhat outward. Petiole 

 fully twice as long as broad, its anteroposteriorly compressed node narrowed 

 above, without spines, but with its rather sharp, transverse margin angularly ex- 

 cised. Postpetiole regularly rectangular, broader than long, broader than the 

 petiole, rather flat above. Gaster about J as large as the head, excluding the 

 mandibles, nearly circular, with rather straight anterior border. Femora 

 thickened in the middle, tibiae clavate. 



Shining; mandibles and clypeus smooth, the former sparsely and finely 

 punctate, the latter without rugosities along its anterior border. Head 

 covered rather uniformly with sparse, punctate foveolae, the triangular space 

 between the two limbs of each scrobe very coarsely reticulate-rugose, the space 

 between the frontal carinae finely, but not uniformly, longitudinally striate, 

 the scrobes transversely striolate. Thorax and postpetiole very coarsely 

 reticulate-rugose, epinotal declivity between the spines, the petiole and gaster 

 very smooth and shining. 



Pilosity much as in dyak, but the hairs longer and more delicate, though 

 blunt, and somewhat more numerous on the head, forming an even row along 

 the anterior border of the antennal scapes and more numerous on the extensor 

 than on the flexor surfaces of the legs. 



Brownish ferruginous; mandibles, antennae, and legs deep red; petiolar node, 

 postpetiole, and gaster black. 



Described from a single specimen taken on Mt. Matang, West 

 Sarawak by Mr. G. E. Bryant and sent me by Mr. Horace Donis- 

 thorpe. 



