390 bulletin: museum of comparative zoology. 



Hairs present on thoracic dorsum, longer and more numerous on 

 head and gaster 15 



15. Gaster black 16 



Gaster brown 17 



16. Body rather opaque; petiole broad, with sharp superior border. 



sanguinca rubicunda Emery. 



Body somewhat shining; petiole narrower, with blunter superior 



border sanguinca rubicunda var. IuciduIa,va,T. nov. 



17. Sides of head convex; clypeal notch shallow; hairs moderately 



abundant; tibiae with very fine appressed pubescence 18 



Sides of head very feebly convex; clypeal notch rather deep; 

 hairs more abundant; anterior surfaces of tibiae with small 

 oblique hairs and without appressed pubescence. 



sanguinca puherula Emery. 



18. Head, thorax, and petiole red, gaster dark brown. Clypeal notch 



feeble but distinct sanguinea subintegra Emery. 



Head, thorax, and petiole yellow, gaster pale brown. Glypeal 

 notch obsolescent . . sanguinca subinicgra var. gilvcsccns, var. nov, 



RUFA GROUP. 



Workers. 



1 . Palaearctic forms 2 



Nearctic forms 12 



2. Frontal area opaque; antennal scapes short and robust; whole 



upper surface of head black uralensis Ruzsky. 



Frontal area shining; antennal scapes longer and more slender; 

 inf uscation of head, when present, less extensive 3 



3. Gaster brown or black, more or less reddish at the base 4 



Gaster entirely black 7 



4. Front, vertex, and a small pronotal spot dark brown or blackish; 



erect hairs on head and thorax usually sparse; eyes hairless. .5 



Front, vertex, and pronotum rarely spotted; body and legs 



usually more hairy ; eyes usually hairy 8 



5. Head long and narrow, with straight cheeks; thorax slender 



riifa var. santschii, nom. nov. 

 Head short, cheeks more convex; thorax robust 6 



6. Head, thorax, and petiole red. 



rufa Linne and its var. rufopratcnsis Forel. 



