56 Journal Xew York Entomological Society. [^'°'- xxn. 



with much shorter and fewer erect hairs on the thorax and gaster, with long, 

 distinct pubescence on the mesonotum, which is glabrous and without pubes- 

 cence in the type. The pubescence on the gaster is also much denser so that 

 it nearly conceals the surface. Wings paler, with paler veins and stigma, and 

 proportionally longer, measuring - mm., compared with 7.5 mm. in the typical 

 interjectus. 



Male. — Also smaller than the corresponding sex of the typical interjectus 

 (3 mm.). Body darker and more opaque, much less hairy, but with more 

 abundant pubescence, especially on the upper surface of the epinotum. 



Described from numerous workers, females and males, taken from 

 large colonies near Guerrero Mill. These were nesting beneath large 

 stones, especially in pine woods and at high altitudes. The males 

 and females were captured during May, whereas those of the typical 

 interjectus are not found in the United States till later in the summer 

 (from the middle of July till the middle of September). 



28. Formica microgyna Wheeler subsp. rasilis Wheeler var. nahua Wheeler. 

 ^^'orkers and females from Guerrero Mill. 



A full account of this and the three following Formicas is given 

 in my recent "Revision of the Ants of the Genus Formica (Linne) 

 Mayr," Bull. Mus. Comp. Zool., LIII, 1913, pp. 562 ct scq. 



29. Formica subcyanea Wheeler. 



\\'orkers, females and males from Guerrero ]Mill, \'elasco, below 

 Real del Monte ; El Chico and Pachuca. 



30. Formica rufibarbis Fabricius var. gnava Buckley. 



Workers, females and males from Guerrero Mill and El Chico. 



31. Formica cinerea Mayr var. altipetens Wheeler. 

 A few workers from Pachuca. 



32. Polyergus rufescens Latreille subsp. breviceps Emery var. montezuma 



new var. 



\\'orker. — Very similar to the typical breviceps of Colorado, but differing 

 in coloration, the general tint of the body being slightly darker and more 

 brownish red, with the legs, the posterior border of the first gastric segment 

 broadly and the succeeding segments entirely fuscous. The pilosity is fully as 

 abundant as in the typical breviceps, differing in this respect from mexicanus 

 Forel, which is scarcely more than a variety, if indeed it be not a synonym 

 of breviceps. 



Female. — Colored like the worker, but the general tint of the body even 

 darker. Veins and stigma of the wings also darker than in the female 

 breviceps. 



Male. — Indistinguishable frnni the male of the typical breviceps. 



