Atta (Trachymyrmex) septentrionalis var. obscurior Wheeler, 1907d: 709 (w.q.) U.S.A. (Texas). Nearctic.

Primary type information: Type-material: syntype workers, syntype queens (numbers not stated). Type-locality: U.S.A.: Texas, Austin (W.M. Wheeler) (by restriction of Wheeler, 1911i: 246). Type-depository: MCZC. Type notes: Other original syntype localities: Texas, Montopolis, Milano (W.M. Wheeler), Texas, Denton (W.H. Long), Texas, Paris (A. Rucker, C.T. Brues), Florida, Miami (M. Treat, T. Pergande), Florida, Jacksonville (W.M. Wheeler).

Infrasubspecies

• A. s. o. crystallina Wheeler, 1911
• A. s. o. irrorata Wheeler, 1911
• A. s. o. seminole Wheeler, 1911