wheeler: ants of the genus formica.  395 



3. Antennal scapes with erect or suberect hairs 4 



Antennal scapes without erect or suberect hairs 5 



4. Hairs on antennal scapes coarse and clavate. . .impexa Wheeler. 

 Hairs on antennal scapes delicate, not clavate. 



microgyna Wheeler. 



5. Border of petiole blunt; head and thorax rich yellowish red. . .6 

 Border of petiole sharp and compressed; head and thorax sordid 



brownish red 10 



6. Gaster black or dark brown, not red at the base 7 



Gaster brown, red at the base 9 



7. Largest workers with the pro- and mesonotum and also the 



ocellar region infuscated. 



microgyna rasilis var. spicata, var. nov. 



Largest workers without the head and thorax infuscated or at 



most with dark ocellar triangle 8 



8. Tibiae with abundant, short, subappressed hairs on their ex- 



tensor surfaces microgyna var. rccidiva, var. nov. 



Tibiae without such hairs microgyna rasilis Wheeler. 



9. Erect hairs on head, thorax, and gaster moderately numerous, 



usually lacking on posterolateral corners of head. 



difficilis Emery. 

 Erect hairs more abundant and longer, especially on the front, 

 gula, and thorax, present on posterolateral corners of head. 



difficilis var. consocians Wheeler. 

 10. Posterior portion of head, a spot on the pronotum and one on 



the mesonotum dark brown or blackish adamsi Wheeler. 



Infuscation of head and thorax more restricted, frontal area 

 smoother and more shining adamsi var. alpina Wheeler. 



Females. 



Gaster reddish yellow like the head and thorax 2 



Gaster brown or black 3 



Tibiae without long, oblique hairs difficilis Emery. 



Tibiae with long, oblique hairs . . difficilis var. consocians Wheeler. 

 Gaster smooth and more or less shining, finely and sparsely 



pubescent 4 



Gaster opaque, with denser, longer pubescence 6 



Antennal scapes without erect hairs. . microgyna scitula, subsp. nov. 

 Antennal scapes with erect hairs 5 



