1903] 



WHEELER . 



TEXAN FORMICIDAE 



103 



Clothed with delicate, appiessed, yellowish hairs ; on the clypeus and mandibles the 

 hairs are longer and suberect. Each gastric segment bears on its posterior edge a row of 

 prominent hairs. 



Pale yellow, dorsal surface faintly tinged with brown; teeth and edges of mandibular 

 blades black. 



Male. Length i mm. 



Mandibles spatulate, their rounded, edentulous blades not meeting with their tips. 

 Clypeus short, with straight anterior border. Antennal 

 scape slender, reaching a little beyond the posterior angle 

 of the head, funiculus with basal joint twice as long as 

 broad and more robust than any of the succeeding joints, 

 joints 3 and 3 hardly longer than broad, joints 4-8 less 

 than one and one half times as long as broad, terminal 

 joints slender, a little shorter than the three preceding 

 joints together. Mesonotum large, overarching the small 

 head, so that it is not seen when the insect is viewed 

 from above. Epinotum flattened. Petiole rather long 

 and thick, anterior surface of node somewhat concave, 

 posterior surface longer and like the ventral surface, 

 convex. Outer genital appendages robust, rounded. 



Surface smooth and shining, gaster somewhat more 

 opaque. 



Pilosity like that of the worker. There are two widely 

 separated, prominent bristles on the disc of the scutel- 

 lum. Genital appendages fringed with prominent hairs. 

 Wings microscopically pilose, the posterior pair especially 

 fringed along their anal borders with rather long white hairs. 



Pale yellow, head brown especially in the ocellar region. Wings and their nervures 

 colorless. 



Fig. 7. a, Brachymyrmex heerii Forel. 

 subsp. depilis Emery. Head of worker. 

 b, B. naneUtis, sp. nov. Head of worker. 



Described from one male and a dozen workers taken under stones in a rather 

 dry open place at Austin, May 25, 1901. The species is certainly rare in central 

 Texas. 



B. nanellus is closely related to B. heerii Forel subsp. depilis Emery, the only 

 other member of the genus known to occur in the United States. The worker 

 na7ienus is distinguished by its much smaller size {B. heerii depilis measures 1.5-2 

 mm.), the shorter funicular joints and maxillary palpi, and the much paler color 

 {depilis is distinctly brown) . The male is also much paler in color than the male 

 of depilis. It is possible that nanellus may have to be reduced to the rank of a 

 subspecies of heerii, when the various species of the extremely difficult American 

 genus Brachymyrmex are subjected to a careful comparative study. 



