March, 1914] W'hEELER : AntS FROM HiDALGO, MeXICO. 41 



5. Eciton (Acamatus) sumichrasti Norton. 



Many workers from several colonies at San ^liguel, Pachuca and 

 Guerrero Mill. One large colony was occupying a temporary nest in 

 a bunch of dead cactus. 



6. Eciton (Acamatus) melanocephalum Emery subsp. xipe new subspecies. 



Worker. — Length 3-5.5 mm. 



Differing from the typical melanocephalum only in the following char- 

 acters : The petiole is nearly twice as long as broad, instead of only slightly 

 longer than broad, the thorax and petiole are dark brownish red, instead of 

 light ferruginous red and the head, except the clypeus) the postpetiole and 

 gaster are black, instead of piceous. 



Numerous specimens were taken at San Miguel from a single 

 colony in the act of plundering a nest of Pheidole vasUti Pergande 

 var. acoUuia var. nov. 



7. Eciton (Acamatus) manni new species. 



Worker. — Length 3-4.5 mm. 



Allied to E. melanocephalum. Head somewhat longer than broad, broader 

 in front than behind, with broadly and feebly excised posterior border and 

 angular posterior corners. Eyes very small and indistinct. Mandibles in the 

 largest workers with oblique blades furnished with two or three small, widely 

 separated teeth, in the small workers toothless and not oblique. Antennae 

 stout, the scapes only about three-fifths as long as the head. Thorax shaped as 

 in melanocephalum, long, narrow, laterally compressed ; pronotum with a trans- 

 verse carina anteriorly, pro- and mesonotum feebly convex above and twice as 

 long as the epinotum, the base of which is straight, horizontal and lower than 

 the mesonotum, separated from it by a shallow but distinct impression, and 

 scarcely longer than the declivity which is slightly concave. Petiole in profile 

 longer than high, evenly convex above, with a small anteroventral tooth ; seen 

 from above it is fully twice as long as broad, with parallel sides ; postpetiole 

 slightly broader and shorter than the petiole, a little longer than broad, 

 broader behind than in front, with rather straight sides, convex upper surface 

 and a small, blunt, anteroventral tooth. Gaster and legs of the usual shape. 

 Claws simple. 



Mandibles subopaque, finely striate and coarsely punctate; head shining, 

 its upper surface in large workers coarsely and sparsely punctate, its lateral 

 and gular surfaces glabrous. Thorax subopaque, finely and densely punctate- 

 rugulose, except the sides of the pronotum, which are very shining and either 

 smooth or very superficially punctate. In the largest workers the inferior 

 meso- and metapleurae are also somewhat shining and the same is true of the 

 pronotum in all specimens, although this region is as deeply and densely punc- 

 tate-rugulose as the meso- and epinotum. Petiole finely punctate-rugulose, 

 upper surface of node slightly shining; postpetiole smoother and more shining, 



