March, 1914] WhEELER : AnTS FROM HlDALGO^ MeXICO. 53 



less than 5 mm., and the veins and stigma are of a deeper brown tint. The 

 antennal scapes resemble those of sulcinodis, being fully half as long as the 

 funiculi, but are somewhat stouter, especially at the base. There are no appre- 

 ciable differences in pilosity between the two forms. In sculpture the following 

 differences may be noted : the petiolar node is irregularly rugulose-punctate, 

 not longitudinally rugose as in sulcinodis, and the postpetiole is also smoother 

 and more shining; the fine rugse on the head are more irregular and not 

 longitudinal. 



Described from many workers and males and three females taken 

 from several colonies at Guerrero Mill. These colonies were found 

 under stones both in the pine woods and on open hill-sides. The 

 status of this form is somewhat doubtftil, as one may be inclined to 

 regard it as a subspecies of sulcinodis. It is certainly singular that 

 it should be more closely related to the European sulcinodis than to 

 any of the nearctic Myrmicas. except M. pnnctivcntris Roger. Even 

 M. brcvinodis Emery, although it has varieties (siibalpina Wheeler 

 and sulcinodoidcs Emery) that approach the European form in sculp- 

 ture and color, differs considerably from sulcinodis in the antennal 

 scapes of the worker and male. The Mexican form is closely re- 

 lated to J\I. pnnctivcntris of the Eastern States. In the worker of this 

 species, however, the petiole is pedunculate and has a larger antero- 

 ventral tooth, the epinotal spines are shorter, the antennae are less 

 angularly bent at the base and the gaster is coarsely punctate. The 

 male punctiventris is much smaller than that of incxicana, but in other 

 respects remarkably similar. 



22. Leptothorax manni new species. 



Worker. — Length 2-2.2 mm. 



Head subrectangular, longer than broad, with broadly roimded posterior 

 border. Mandibles s-toothed. Clypeus convex, its anterior border very feebly 

 and sinuately emarginate in the middle. Frontal area distinct. Antennae 12- 

 jointed ; scapes reaching very nearly to the posterior border of the head ; first 

 funicular joint as long as joints 2—5 together; joints 2-6 a little broader than 

 long, 7 and 8 as long as broad ; terminal longer than the two penultimate joints 

 of the 3-jointed club. Thorax flattened above and on the sides, a little nar- 

 rower behind than in front, not constricted when seen from above and with- 

 out impressed sutures on the dorsal surface, which, therefore, in profile is 

 perfectly even and nearly straight. Humeri rather prominent, subangular ; base 

 and declivity of epinotum in profile subequal, the latter sloping, armed with 

 two small, suberect teeth, which are not longer than broad at their bases. 

 Petiole subpedunculate, seen from above pyriform, broader behind than in 



