Key to species of Australian Aphaenogaster based on workers

1. Majority of hairs on venter of head located laterally and forming a distinct psammophore, only scattered hairs on central portion (Fig. 4) ................................................................................................................... 2

- Hairs on venter of head randomly distributed and not forming a distinct psammophore (Fig. 2) .............. 4

2 Eye relatively large (EI greater than 21, Fig. 19); scape relatively long (SI greater than 106, Fig. 20)........ ...................................................................................................................................................... mediterrae

- Eye relatively small (EI less than 21, Fig. 19); scape relatively short (SI less than 106, Fig. 20) .............. 3

3. Petiolar node (in dorsal view) wider than long; mandibular sculpture composed of irregularly sized stria- tions (Fig. 6) (occurring in Western Australia) ................................................................................. poultoni

- Petiolar node (in dorsal view) approximately square; mandibular sculpture composed of regularly sized striations (Fig. 5) (occurring in South Australia and eastward) ...................................................... barbigula

4. Posterior margin of head nearly flat in full face view, extending laterally of the occipital collar before

passing through a distinct posterolateral corner into the lateral margin of the head (Fig. 15) .................... 5 - Posterior margin of head broadly arched in full face view, the arch beginning at the occipital collar and with at most a weak angle separating the posterior and lateral margins of the head (often posterior and lateral margins forming a continuous surface) (Fig. 9) ................................................................................... 6 5. Scape relatively short (SI less than 125, Fig. 23) (occurring in e. Queensland and ne. New South Wales) ............................................................................................................................................................. pythia

- Scape relatively long (SI greater than 135, Fig. 23) (occurring in Northern Territory) .................. reichelae

6. Shorter erect hairs on mesosomal dorsum (especially those on mesonotum) with blunt tips; dorsal surfaces of propodeum and propodeal spines connected through a gentle concavity (so that the base of each spine is at approximately the same level as the dorsal surface of the propodeum) (Fig. 10) .................. longiceps

- Erect hairs on mesosomal dorsum tapering to sharp points; dorsal surfaces of propodeum and propodeal spines connected through a gentle concavity followed by a gentle convexity (so that the base of each spine is raised slightly above the dorsal surface of the propodeum) (Fig. 8)........................................................ 7

7. Head relatively narrow (Fig. 21), scape relatively long (Fig. 22) (occurring in n. Northern Territory and n. Western Australia) .................................................................................................................. kimberleyensis

- Head relatively broad (Fig. 21), scape relatively short (Fig. 22) (occurring in Queensland) ........... barbara