392 bulletin: museum of comparative zoology. 



18. Petiole narrow and very low, its border very blunt and not 



produced upward in the middle ferocula, sp. nov. 



Petiole broader and higher, its border sharp, more or less pro- 

 duced upward in the middle 19 



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



20 

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



22 



20. Small forms (4-6.5 mm.) criniventris Wheeler. 



Larger forms (4-9 mm.) 21 



21. Gaster black, somewhat shining, with short, sparse pubescence. 



truncicola Integra Nylander. 

 Gaster dark brown, opaque, densely gray pubescent. 



truncicola integroides Emery var. haemorrhoidalis Emery. 



22. Eyes hairless 23 



Eyes hairy 26 



23. Erect hairs on gaster very numerous, very short and stubby ... 24 

 Erect hairs on gaster less numerous, longer 25 



24. Gaster blackish brown comata Wheeler. 



Gaster reddish brown ciliata Mayr. 



25. Gaster dark brown, opaque, densely gray pubescent. 



truncicola mucescens, subsp. nov. 

 Gaster black, somewhat shining, finely and sparsely pubescent. 



truncicola obscurivcntris var. gyinnomma Wheeler. 



26. Head and thorax of small workers decidedly darker than in 



largest workers 27 



Head and thorax of small workers scarcely or not at all darker 

 than in largest workers 30 



27. Flexor surfaces of tibiae with erect hairs 28 



Flexor surfaces of tibiae without erect hairs 29 



28. Thorax of large workers bright red like the head or at most very 



feebly infuscated; pubescence on gaster dense. 



rufa aggerans Wheeler. 



Thorax of large workers deeply infuscated; pubescence on 



gaster more dilute rvfa aggerans var. melanotica Emery. 



29. Head and thorax of large workers entirely or almost entirely 



without dark spots rufa obscuripes Forel. 



Front, vertex, occiput, and thoracic dorsum of large workers 

 blackish rufa obscuripes var. tohymperi Forel. 



30. Gaster brown, opaque, densely gray pubescent 31 



Gaster black, feebly shining, sparsely and finely pubescent. 



truncicola obscurivcntris Mayr. 



