296 



HENRY C. MCCOOK. 



Family, FOR.MICARI.£. 



Sab-family. Formicid.k. First Division. Workeis. — The abdomen seen from 

 above, shows five segments, of which the fifth is conical and terminal ; the anus 

 is small, circular, apical, and ciliated at its edge. Spurs simple; poison vessel 

 cushioned ; nymphs nearly always enclosed in cocoons. The bowl of the gizzard 

 spherical, or a little wanting of spherical. The chaperon is not prolonged be- 

 tween the frontal ridges {ar c ten frontal es), beyond their origin. 



Females. — Exactly corresponding with workers. "Wings with one cubital cell. 



Genus, Formicn, Linn. Workers. — Mandibles broad, toothed at the outer 

 border, as with other genera. Metanotum bossed, (bossu), but not more elevated 

 than the rest of the thorax. Labial palpi with four joints. The anterior part of 

 the chaperon is advanced at the mddle and pulls out the origin of the labrum 

 (labi-e), like the eaves of a roof, (en avant toit). 



Frontal area triangular, very distinct; ocelli likewise very distinct, as is also 

 the frontal furrow. The maxillary palpi with six, sometimes with five joints. 

 The joints of the flagellum of the antennse continue to diminish in length and 

 thickness from the first to the tenth ; the eleventh (twelfth of the antennse), is 

 on the other hand a little longer. Scale vertical, calix of the gizzard {gcsier), a 

 little greater than the bowl. 



Females. — Frontal area triangular, very distinct; characters (thorax excepted), 

 identical with those of the worker. 



Males. — External genital organs large. Exterior genital valvules cultriform. 

 Frontal area, palpi, gizzard as with ^. Median lobule of the last joint of the 

 posterior tarsi having scarcely half the length of the hooks, (crochets). Scale 

 vertical, thick. Body robust; size often equal to that of the 9- 



Species, F. ruTa. Workers. — Chaperon entire at its anterior edge, size very 



variable, body thick-set, {ramasse). 

 Head and abdomen much wider 

 than the thorax. The notch between 

 the mesonotnm and the metanotum 

 large. Metanotum greatly arched. 

 Of a fallow red color quite lively, 

 (varying in brightness), more or less 

 mixed with brown and black, but 

 the boundaries of the colors always 

 quite plain, except with the very 

 small individuals, (dwarfs). Eyesand 

 ocelli large. Chaperon with a keel 

 indistinct or distinct only on its an- 

 terior half. The frontal area always 



(.. .. (d J " .\i „ " ' ' j i^ff smooth and shining. This ant has the 

 tensis. m, mandibles, c, chaperon, j, leit ^ 



jaw. /,front. v, vertex. o,ocelli. e.lefteye. habit of ejecting its venom. Nests 

 fu, frontal furrow, r, left frontal ridge, niadeof gathered materials. Nymphs 

 af right antennal fosse. Sc, scape of right almost always in cocoons, 

 antennae, a?-, frontal area. t^ , ... i . i 



Females. — Abdomen short, almost 



spherical, body thick-set, squat {trajru), very robust; thorax elevated; head 

 much larger than the thorax. Frontal area always smooth and very shining. 

 Color of worker. L. 9 — 11 mm. 



Mates. — Body robust, broad, very hairy, black. External genital organs and 

 frequently the legs of a yellowish-red. L. 9^11 mm. 



