Key to species of Trachymyrmex workers in the southeastern United States

(from Creighton, 1950; Wild, 2010)

Color dark brown; only found in southern FL in the US
  Color reddish-brown; widespread or only found in LA and TX in the US
...2
2 Frontal lobe angular, somewhat boot-shaped, not entirely covering base of antenna; from posterior edge of frontal lobe to posterior corner of head, the frontal carina is approximately 3/4 the length of head; in full face view, posterior edge of head mostly straight, only slightly concave, posterior corners with enlarged projections; nests with asymmetric mounds of excavated soil
  Frontal lobe semi-circular, enlarged, entirely covering base of antenna; from posterior edge of frontal lobe to posterior corner of head the frontal carina is approximately 1/2 the length of head; in full face view, posterior edge of head distinctly V-shaped, posterior corners with only typical projections as are found at edges of head; nest entrances with conspicuous turret