Myrmecina ^{HNS ZBK} Curtis

Myrmecina ^{HNS ZBK} Curtis 1829: 265. Type species: Formica graminicola Latreille ^HNS 1802, by monotypy.

Diagnosis. The sides of the head behind the eyes with an elongate ridge or groove on each side which starts at the mandibles, runs the length of the head and ends near the upper corners. In side view, the petiole is low, rounded and barrel-shaped and lacks a distinct node. The propodeum is armed with long spines near the angle as well as short spines or angles near the metanotal groove. The distinctive ridge on the sides of the head behind the eyes combined with the low, rounded petiole will separate these ants from all others in Australia.

List of Australian species

alpina ^{HNS ZBK} sp. n.

australis Wheeler ^HNS and Wheeler

difficulta ^{HNS ZBK} sp. n.

eruga ^{HNS ZBK} sp. n.

inaequala ^{HNS ZBK} sp. n.

pumila ^{HNS ZBK} sp. n.

rugosa Forel ^HNS

silvalaeva ^{HNS ZBK} sp. n.

silvampla ^{HNS ZBK} sp. n.

silvangula ^{HNS ZBK} sp. n.

silvarugosa ^{HNS ZBK} sp. n.

silvatransversa ^{HNS ZBK} sp. n.

wesselensis ^{HNS ZBK} sp. n.

Key to Australian Myrmecina ^{HNS ZBK} based on workers

1. First segment of funiculus expanded laterally, with strongly convex sides and appearing essentially spherical........... ......................................................................................................................................................................... australis ^HNS

-. First segment of funiculus narrower, with nearly straight sides and essentially cone-shaped ................................... 2

2. Sculpturing on pronotum forming continuous transverse carinae which form shallow arches to deep "V"s............. 3

-. Sculpturing on pronotum running longitudinally and generally with the central carina (or carinae) running nearly the length of the mesosoma, or occasionally sculpturing ill-defined and irregular...........................................................7

3. Sides of head behind compound eyes with 2-3 longitudinal carinae running the length of the head........ silvarugosa ^{HNS ZBK}

-. Sides of head behind compound eyes smooth............................................................................................................4

4. Dorsal surface of pronotum immediately behind the collar with at most very weak sculpturing (sometimes nearly smooth) ......................................................................................................................................................... silvalaeva ^{HNS ZBK}

-. Dorsal surface of pronotum continuously sculptured, the area immediately behind the collar not differing significantly from more posterior regions .............................................................................................................................. 5

5. Antennal scapes smooth; body larger (HW> 0.8mm).................................................................................. silvampla ^{HNS ZBK}

-. Antennal scapes with low longitudinal ridges; body smaller (HW <0.7mm) ........................................................... 6

6. Majority of carinae on pronotum and mesonotum gently curved across width of mesosoma ............. silvatransversa ^{HNS ZBK}

-. Majority of carinae on pronotum and mesonotum "V"-shaped.................................................................... silvangula ^{HNS ZBK}

7. Sides of head behind compound eyes with 2-3 longitudinal carinae running the length of the head................ alpina ^{HNS ZBK}

-. Sides of head behind compound eyes smooth............................................................................................................. 8

8. Dorsal surface of pronotum immediately behind the collar with at most very weak sculpturing (sometimes nearly smooth) ........................................................................................................................................................................ 9

-. Dorsal surface of pronotum continuously sculptured, the area immediately behind the collar not differing significantly from more posterior regions............................................................................................................................. 10

9. Body larger (HW> 0.65mm, MTL> 0.35mm); head squarer (CI> 95)............................................................. eruga ^{HNS ZBK}

-. Body smaller (HW <0.60mm, MTL <0.30mm); head more elongate (CI <95).............................................. pumila ^{HNS ZBK}

10. Dorsal surface of pronotum with irregular, ill-defined sculpturing.................................................................... rugosa ^HNS

-. Dorsal surface of pronotum with continuous longitudinal carinae.............................................................................11

11. Erect hairs on gaster (and most on mesonotum) strongly curved so their tips are nearly parallel with the surface of the body (known only from the Wessell Islands, Northern Territory) ........................................................ wesselensis ^{HNS ZBK}

-. Erect hairs on gaster (and longer ones on mesonotum) only weakly curved with their tips at a strong angle with body (coastal Queensland and north-eastern New South Wales) ........................................................................................ 12

12. Carinae extending continuously from the dorsal surface onto the lateral surfaces of the mesosoma and not interrupted as they cross the angle separating the dorsal and lateral surfaces ....................................................... difficulta ^{HNS ZBK}

-. Dorsal and lateral surfaces of mesosoma separated by an indistinct angle or ridge which interrupts or breaks the mesosomal sculpturing................................................................................................................................... inaequala ^{HNS ZBK}