wheeler: ants of the genus formica. 411 



F. sanguinea subsp. subintegra Wheeler, Bull. Amer. mus. nat. hist., 1908, 

 24, p. 627; Ants, 1910, p. 458, 570. 



Worker. Length 4-7 mm. 



Head with the posterior corners and sides more rounded than in 

 the preceding forms. Clypeus with broad but shallow emargination. 

 x\ntennal scapes usually but slightly thickened towards their tips. 

 Pro- and mesonotum not very convex, epinotum somewhat rounded in 

 profile. Petiole thick anteroposteriorly, narrow seen from behind, 

 convex in front, flattened behind, with blunt, usually entire superior 

 border. 



Surface of body rather smooth and somewhat lustrous or shining, 

 especially the mandibles and posterior corners of the head; frontal 

 area shining, except in the middle. 



Pilosity and pubescence yellow, the former represented by a few 

 hairs on the dorsal surface of the head, sometimes a few on the pro- 

 notum and by a number of scattered hairs on the gaster, longest at 

 the tip and on the venter. Rarely there are a few hairs on the petiolar 

 border, and on the gula. Pubescence abundant and dense on the 

 gaster, somewhat finer on the remainder of the body but clearly visible 

 under a lens magnifying 16 diameters. Surfaces of femora and tibiae 

 with very fine, appressed pubescence, which is dense on their anterior 

 and sparse on their posterior faces. Femora without hairs, tibiae 

 with a row of graduated bristles on the flexor surface. 



Red color of head, thorax, petiole and appendages usually tinged 

 with yellow. Mandibles darker, with black teeth. Gaster brown. 



Female. Length 7-9 mm. 



Closely resembling the worker in pilosity and color. Surface of 

 body more opaque. Mandibles, cl3^peus, front, antennae, tibiae, 

 and tarsi and sometimes also three spots on the mesonotum, brownish. 

 Wings rather heavily infuscated at their bases. Petiole like that of 

 the worker but broader. 



Male. Length 7-8 mm. 



Mandibles with rather narrow blades, pointed, edentate. Clypeus 

 with rounded, entire anterior border, carinate, often with an indis- 

 tinct transverse impression just back of its anterior border and another 

 near its posterior end. Petiole thick, transverse, with blunt, feebly 

 and broadly excised dorsal margin. 



Pubescence similar to that of the worker, more dilute on the gaster, 

 so that this region appears more shining. Erect hairs very short, 

 confined to top of head, mesonotum and scutellum. 



Body black; antennae brown; legs and genitalia yellow; wings 

 rather more heavily infuscated than in the female. 



Hosts (Slaves). F. fusca and its vars. suhsericea, svhaenescens, 

 F. cinerea var. neocinerea, F. neogagates and vidua; F. pallidefulva 

 schaufussi, nitidiventris, fuscata, and incerta. 



