1907.] Wheeler, Fungus-growing Ants of North America. 715 



in front, with broadly and obtusely excised posterior margin, subparallel sides and 

 rather acute posterior corners. Eyes moderately convex, just in front of the middle 

 of the head. Mandibles convex, with two large, acute apical and several small and 

 indistinct basal teeth. Clypeus moderately convex, with entire, broadly rounded 

 anterior margin. Frontal area large, triangular, distinct. Frontal carinse with 

 very large, broad, flattened lobes anteriorly overlapping the insertions of the antennse. 

 These lobes have acute anterolateral corners and are separated by distinct reentrant 

 angles from the posterior ridges which are straight, diverging and continued back to 

 the posterior corners of the head. Latei'al carinae continued back only a little behind 

 the eyes where they turn in but fail to meet the frontal carinse, though leaving a 

 marked groove for the accommodation of the scape and extending to the posterior 

 corner. Antennse robust, scapes somewhat thickened distally, reaching with their 

 tips to the posterior corners. Thorax long and stout, especially in front, though 

 decidedly narrower than the head. Pronotum without inferior spines, with a pair 

 of obtuse spines at the hmneral angles and a pair of tubercles in the middle almost 

 as far apart as each is from a lateral spine. Mesonotum with a blunt ridge on each 

 side, somewhat higher in front and behind than in the middle. These ridges con- 

 verge rapidly behind and just in front of the deep mesoepinotal constriction. Epi- 

 notum in profile with subequal base and decli^^ty, the former convex, especially in 

 front, with a pair of ridges diverging posteriorly and continued into the small rather 

 blunt spines, which are but little longer than broad at their bases, and directed up- 

 ward, backward and outward. Epinotal declivity sloping, concave. Petiole from 

 above suboblong, broader than long, a little broader behind than in front where it 

 is suddenly constricted into a short peduncle; node above with a pair of rather acute 

 teeth. Postpetiole H times as broad as the petiole, broader behind than in front, 

 sides slightly rounded, posterior border angularly excised in the middle. Gaster 

 suboblong, broader behind than in front, not impressed in the middle above, anterior 

 and lateral borders straight, the latter with indistinct longitudinal ridges. Legs 

 rather long and stout. 



Opaque throughout; mandibles very finely striated, especially at the base. 

 Body very finely granular; front and vertex longitudinally rugulose; first gastric 

 segment covered uniformly with minute tubercles. 



Hairs whitish, suberect, curved and short on the body and appendages, longer 

 and more conspicuous on the clypeus and mandibles. 



Ferruginous Ijrown; upper surface of head more or less blackish. 



Female. Length: 2.5-2.7 mm. 



Head resembling that of the worker, anterolateral corners of frontal carinte 

 mbre acute; ocelli very small and indistinct. Pronotum large, with a pair of stout, 

 acuminate superior spines directed forward, outward and upward. Mesonotum 

 small, elliptical, flattened, somewhat narrowed in front, with distinct but .shallow 

 Mayrian furrows. Scutellum as long as broad, with excised posterior border and 

 acute posterior angles. Epinotum with short, convex base, long concave and verti- 

 cal declivity and short spines directed backward and outward. Petiole, postjietiole 

 and gaster resembling those of the worker. Wings short (2 mm.) and rouniled; 

 venation like that of Trachynij/nnrx and Cyphomyrmcx but with the inner branch 

 of the cubital and the distal segment of the externomedian veins very faint or ob.so- 

 lete. 



Like the worker in .sculpture, pilosity and coloration, l)ut with the mesonotum 



