420 bulletin: museum of comparative zoology. 



broader but very shallow emargination. Head large, broader than 

 the thorax, scarcely longer than broad. Antennal scapes reaching 

 only a distance equal to their own diameter beyond the posterior 

 comers of the head. Infuscation of top of head deeper and more 

 extensive than in the worker, covering also the cheeks and clypeus. 

 Mandibles brown. Mesonotum immaculate. Metanotum and pos- 

 terior border of pronotum infuscated. Petiole like that of the worker 

 in shape. Wings whitish hyaline, without any trace of infuscation, 

 veins and stigma brown. 



Host (Slave). F. ncogagates. 



Described from nine workers and four females taken Aug. 8, 1903, 

 from a small colony in the open fields at Broadmoor, near Colorado 

 Springs, Colo. The nest contained several small workers of F. ncoga- 

 gates, which were in all probability the slaves of the new species, since 

 winged females of the latter were found in the nest. At first sight 

 F. emeryi appears to be merely a variety or subspecies of pergandei, 

 but closer examination shows many dissimilarities, especially the 

 smaller size, the greater breadth of the head, the much feebler pilosity, 

 the deeper color, the more opaque surface, and the shape of the thorax 

 in profile. The slight transverse depression in the base of the mesono- 

 tum is constant in all my specimens. The female may be readily 

 distinguished from the females of sanguinea and munda by its color, 

 from sanguinea also by the pale,, colorless wings, and from munda by 

 its much larger head and shorter antennal scapes. 



17. F. manni, sp. nov. 



Worker. Length 3.5-4.5 mm.  



Body slender. Head, excluding the mandibles, longer than broad, 

 a little narrower in front than behind, with straight sides and feebly 

 con^^ex posterior border. Clypeus carinate, its anterior border feebly 

 and rather broadly notched in the middle. Frontal carinae sub- 

 parallel behind. Antennae slender, scapes not incrassated toward 

 their tips. Thorax long, pro- and mesonotum moderately convex; 

 mesoepinotal constriction shallow; epinotum angular in profile, with 

 subequal base and declivity. Petiole rather narrow; in profile cune- 

 ate, rather thick at the base, gradually narrowed towards the summit, 

 with nearly flat anterior and posterior surfaces, the border rather sharp ; 

 seen from behind entire or very feebly excised in the middle. Legs 

 rather long. 



Body very finely shagreened, shining, especially the gaster; the 

 clypeus and mandibles somewhat more opaque, finely striated, the 

 former also sparsely punctate. 



