710 Bulletin American Museum of Natural History. [\^ol. XXIII, 



Hairs brown, hooked, suberect, covering the body and appendages, except the 

 antennal funicuH which are clothed with a very fine whitish pubescence. 



Ferruginous brown; front and vertex dark ))roA\n, legs somewhat paler than the 

 body. In old specimens the body is darker in color and the roughened portions are 

 overlaid with a bluish bloom. 



Female. Length: 4-4.5 mm. 



Head resembling that of the worker. Pronotum with short, acute inferior and 

 superior spines, the latter not flattened. Scutellum with two long, blunt teeth and 

 a deep median excision in its posterior border. Base of epinotum barely half as 

 long as the declivity, which is concave; spines long, stout and rather blunt. Pedicel 

 and gaster similar to those of the worker; posterior border of the postpetiole entire. 

 Wings 6 mm. long. 



Sculpture similar to that of the worker. Mesonotum and scutellum with indis- 

 tinct longitudinal rows of small tubercles; remainder of thorax granular, with minute, 

 scattered tubercles. 



Pilosity and color like those of the worker. Wings opaque brown, with darker 

 veins. 



Texas: Austin, INIontopolis, Marble Falls, Fort Stockton, Paisano Pass^ 

 Marfa, Del Rio, Langti;v (Wheeler). 



The worker of this species may be readily distinguished from that of 

 se-ptentrionalis by the more pointed posterior corners of the head, the much 

 shorter antennal scapes which do not extend beyond the posterior corners, 

 the unpaired pronotal spine, and the rougher legs and gaster. The female 

 turrifex is distinguished by several of these characters and also by the much 

 longer and paler wings. 



7. Atta (Trachymyrmex) arizonensis sp. nov. 



Female (dealated). (PI. XLIX, Figs. 9 and 10.) Length: 4.75 mm. 



Head, without the mandibles, as broad as long, somewhat broader behind than 

 in front, with straight sides, obtusely excised posterior margin and rather pointed 

 posterior corners. Eyes moderately convex, in front of the middle of the sides. 

 Mandibles with two larger apical and several smaller basal teeth. Anterior border 

 of clypeus sinuately notched in the middle. Frontal area triangular, indistinct. 

 Frontal carinse with large reflected and rather angular lobes, without rounded impres- 

 sions in their surfaces, continued back as diverging ridges nearly to the posterior 

 corners of the head, but not meeting the much shorter lateral carince. Antennal 

 scapes distally enlarged, extending about \ their length beyond the posterior corners 

 of the head. The latter with numerous conical tubercles, two of which on the 

 inferior occipital angles are somewhat larger than the others and double. Pronotum 

 with two small, flat, lappet-like inferior spines and a pair of long, but not compressed 

 superior spines, directed outward and slightly forward. Posterior border of scutel- 

 lum with a broad median excision and a pair of blunt teeth. Base of epinotum 

 sloping, about half as long as the concave declivity. Spines short, acute, a little 

 longer than broad at the base, directed backward and outward. All the spines of 



