422 bulletin: museum of comparative zoology. 



hind. Eyes rather small. Maxillary palpi moderately long. Pro- 

 and mesonotum, especially the latter, convex; mesoepinotal constric- 

 tion short and rather deep; epinotum in profile with subequal base 

 and declivity, both straight and forming a large, obtuse angle with 

 each other. Petiole narrow, cuneate in profile, thick at the base, its 

 anterior surface rather strongly convex, its posterior surface flat, its 

 border obtuse, seen from behind rounded and entire. Legs rather 

 stout. 



Body and legs shining; very delicately shagreened, more coarsely 

 on the metapleurae. Mandibles and clypeus subopaque, very finely 

 and densely longitudinally striated, the former also with small, sparse, 

 shallow punctures. Frontal area smooth and shining. 



Head, throax, border of petiole, gaster, and fore coxae beset with 

 long, erect, subobtuse, rather slender, silvery white hairs; those on 

 the gula being as long as those on the upper surface of the head. Legs 

 with only a row of hairs on the flexor surfaces of the femora and the 

 usual row of bristles on the corresponding surfaces of the tibiae. 

 Pubescence white, long, and sparse on the gaster, shorter and even 

 sparser on the head, thorax, and legs, very fine and dense on the scapes. 



Yellowish red; gaster black; in small workers the posterodorsal 

 portion of the head, and the upper surface of the thorax and petiolar 

 border often dark red or brownish. 



Female. Length 7.5-9 mm. 



Closely resemblng the worker in color, sculpture, and pilosity, but 

 the posterodorsal portion of the head, three large blotches on the 

 mesonotum, the metanotum, and often also the posterior portion of 

 the scutellum, and portions of the meso- and metapleurae fuscous. 

 Gaster sometimes dark reddish brown, with a pale red spot at the 

 base of the first segment. Wings colorless, with brown veins and 

 black stigma. The middle of the clypeal border is flattened, and has a 

 broad but shallow, sinuous excision. The petiole is broad, with a 

 compressed, sharp border which is often produced upward in the middle 

 as a blunt angle. 



Male. Length: 7-8 mm. 



Mandibles rather short and broad, pointed, edentate. Head broad 

 behind, with straight border, much narrowed in front, with straight 

 cheeks. Eyes large. Clypeus convex, with entire, broadly rounded 

 anterior border. Thorax and gaster rather slender. Petiole low and 

 transverse, somewhat compressed anteroposteriorly, especially above, 

 so that the border is less blunt than in the males of many other 

 species of Formica ; seen from behind the border is feebly and broadly 

 excised. Stipes of genitalia with their tips projecting some distance 

 beyond the volsellae and sagittae. 



Head and thorax, including the frontal area, opaque. Mandibles, 

 pleurae, and gaster somewhat shining. 



