wheeler: ants of the genus formica. 391 



Head, thorax, petiole, and legs brown; hairs sparser. 



rufa var. meridionalis Ruzsky. 



7. Head, thorax, and petiole red; black spots on head and thorax 



large, those on the pro- and mesonotum confluent. 



rufa prafensis Retzius. 



Head, thorax, petiole, and legs darker and more brownish; black 



on thorax more extensive. . . rufa pratensis var. nigricans Emery. 



8. Flexor surfaces of tibiae with numerous erect or suberect hairs . . 9 

 Flexor surfaces of tibiae without erect hairs 11 



9. Color of head, thorax, and petiole bright, yellowish red 10 



Color and pilosity transitional to pratensis. 



rufa pratensis var. truncicolo-pratensis Forel. 



10. Hairs on head and thorax abundant; eyes hairy; gaster dark 



brown, with red basal spot truncicola Nylander. 



Hairs absent on head and thorax; gaster opaque, black, with red 

 basal spot truncicola dusmeti Emery 



11. Bright red; upper surface of head and clypeus hairy. 



truncicola var. yessensis Forel. 

 Deep, dull red; upper surface of head and clypeus without hairs. 



truncicola var. sinensis, var. nov. 



12. Antennal scapes with erect hairs 13 



Antennal scapes without erect hairs 14 



13. Head and thorax bright yellowish red; legs reddish brown. 



oreas Wheeler. 

 Red portions of body darker ; legs dark brown ; erect hairs on all 

 parts of the body more abundant, shorter on gaster. 



oreas var. coinptula, var. nov. 



14. Cheeks and posterior corners of head very convex and rounded; 



petiole narrow below when seen from behind, broadened above, 



with straight transverse superior border 15 



Cheeks and posterior corners of head less convex and rounded, 

 petiole not transversely truncated above 17 



15. Erect hairs absent on gula and upper surface of head, thorax, and 



petiole 16 



Erect hairs present on gula and upper surface of head, thorax, and 

 petiole dakotensis Emery var. montigena Wheeler. 



16. Gaster black or very dark brown; pubescence on head and 



thorax very short and indistinct dakotensis Emery. 



Gaster paler; pubescence longer and more distinct on head and 

 thorax dakotensis var. specularis Emery. 



17. Frontal area opaque foreliana, sp. nov. 



Frontal area smooth and shining 18- 



