1907.] Wheeler, Fungus-growing Ants of North America. 707 



tuse angle with the base. The upper surface of the thorax and all the spine.s, with 

 the exception of the inferior pronotal pair are covered with .small tubercles. Petiolar 

 node from above nearly square, a little broader than long; in profile its anterior 

 surface is flattened, its summit acute and furnished with a pair of teeth. On each 

 side of these there is also a small blunt tooth. Postpetiole about as broad as the 

 epinotum, somewhat more than twice as broad as the petiole, and distinctly broader 

 than long, subpentagonal from above, concave in the middle behind and covered with 

 small tubercles. Gaster pyrifonii, broadest behind the middle; first .segment with 

 a faint, longitudinal, median depression and a short ridge on each lateral border. 

 The dorsal surface is covered rather unifonnly with small, acute tubercles, as are 

 also the antennal scapes. 



Mandibles and anterior border of clypeus faintly shining or glossy, the former 

 finely and densely striated. Remainder of body and appendages opaque and indis- 

 tinctly granular. 



Hairs brownish yellow, short, hooked, more or less erect and not very abundant, 

 usually arising from the small tubercles and covering the body and appendages 

 rather uniformly. 



Body ferruginous brown, legs slightly paler, mandibular teeth black, front and 

 vertex dark brown; gaster in many specimens with a broad longitudinal fuscous or 

 blackish stripe on the middle of the first segment. 



Female. Length: 3.8-4 mm. 



Head resembling that of the worker. Pronotum besides the blunt, downwardly 

 directed inferior spines, with a pair of strong, somewhat flattened, acute superior 

 spines directed outward and somewhat forward. Scutellum semicircularly excised 

 and bidentate behind. Epinotal spines long, of rather uniform thickness to within 

 a short distance of their acute, rapidly tapering tips. Pedicel and gaster as in the 

 worker, but the lateral teeth of the petiole are smaller and blunter and the posterior 

 margin of the postpetiole is excised. Wings 4 mm. long. 



Sculpture similar to that of the worker; mesonotum and scutellum covered 

 with rows of small elongated tubercles. 



Like the worker also in pilo.sity and coloration. Head with a large black spot 

 on the ocellar region and the gastric stripe is deeper and more distinct, but not 

 reaching the anterior border of the basal segment. Wings blackish with veins of the 

 same color; costal cell yellowish. 



Male. Length: 3-3.5 mm. 



Head but little broader behind than in front, broadest in the region of the eyes, 

 with slightly convex posterior border. Eyes convex, posterior orbits at the middle 

 of the head. Mandibles like those of the worker but smaller. Clypeus with broad, 

 entire anterior margin. Frontal carinse lobed in front, uniting behind with the lateral 

 carina, which are furnished with a small tooth in the middle. Posterior corners of 

 head with several small, acute spines or teeth. Antenme slender; scapes somewhat 

 thickened distally and surpassing the posterior corners by about J of their length. 

 Pronotum with small acute superior and inferior teeth. INIesonotum with well- 

 developed Mayrian furrows. Scutellum similar to that of the female. Epinotum 

 with subequal base and decHvity; spines slender, acute, diverging, bent downward 

 at their tips, their bases continued forward as a pair of crenated ridges on to the 

 ba.se of the epinotum. Petiole and postpetiole like tho.se of the worker, but the 



