1903] 



WHEELER: — TEXAN FORMICIDAE 



lOI 



tion of the antennal scape when folded back. Just behind the posterior angle of the head 

 there is a prominent projection. Antennal scape robust, hardly extending bejond the poste- 

 rior corner of the head; funiculus long, its joints all distinctly longer than broad. Pro- 

 and mesonotum high, arched dorsally above the epinotum which is separated by a deep con- 

 striction from the mesonotum and has its basal surface of about the same length as its abrupt 

 and somewhat concave declivity. Sides of mesonotum carinate. The thorax is armed with 

 the following prominent spines and protuberances : pronotum with two spines on either side 

 and a double tubercle in the mid-dorsal line : mesonotum with a large blunt tubercle at either 

 anterior corner and farther back a pair of smaller spine-like tubercles which are much closer 

 together than the anterior pair; epinotum with 

 a pair of prominent spines, the bases of which 

 are continued forward as ridges bordering the 

 basal dorsal surface of the epinotum. These 

 spines are longer than their distance apart at 

 their bases, and are directed outwards, back- 

 wards, and upwards. Petiole in profile de- 

 pressed, the pedicel rising gradually into the 

 somewhat rounded node, sides subcarinate, 

 ventral surface with a small acute tooth at the 

 extreme anterior end; seen from above the 

 node is oblong, distinctly longer than broad. 

 Postpetiole nearly twice as broad as long, its 

 anterior border rounded, its posterior border 

 straight, with a large depression in the mid- 

 dorsal line ; the sides are distinctly carinate. 

 Gaster somewhat oblong when seen from above, 

 slightly flattened ; in profile more pyriform, 

 sides faintly carinate. Legs of the usual 

 conformation. 



Mandibles subopaque, finely striated, the 

 edges of the blades with a row of shallow, 

 elongate depressions. Body, legs, and antennal 

 scape opaque, roughened, covei-ed with small 

 tubercles, which are more or less connected by 

 low confluent ridges on the head and thorax. 

 Even the thoracic spines are covered with 

 these tubercles. On the gaster they are very 

 unifoi^mly distributed. Funicular joints smooth. 



Hairs rather uniformly covering the body, legs, and antennal scape, brown, short, and 

 more or less recurved or hooked. 



Rich reddish brown throughout; teeth of mandibles and dorsal surface of head between 

 the frontal carinae, black. In old specimens the body is much darker in color and its rough- 

 ened portions are overlaid with a bluish bloom which is intensified when the insect is boiled 

 in caustic potash. Young specimens are paler yellowish brown. 



Female. Length 4-4.5 mm. 



Very similar to the worker in the structure of the head, pedicel, gaster, and appendages. 

 Pronotum with a prominent tubercle on either side, mesonotum and paraptera flat, without 



Fig. 6. a, Atta {Trachyinyrtne.r) turri/ex,sp. nov. 

 Head of worker. b,A. (T.) se/ieftin'ofialis McCook. 

 Head of worker. 



