Key to genera of Australian Geocorinae

1. Pronotum with short curved transverse line-like impressed groove across each callus (Figs. 124–126) [1 Australian sp.].............................................................................................. Unicageocoris

-. Pronotum without a line-like impressed groove across each callus............................................... 2

2. Dorsum of head between eyes densely covered with coarse punctures (Figs. 118, 144)............................... 3

-. Dorsum of head between eyes impunctate or at most corrugated but not punctate (Figs. 3, 11).......................... 4

3. Body flat above; pronotal margins carinate and explanate for entire length; most of corium densely uniformly, irregularly and finely punctate; spiracle II ventral; abdominal sterna III and IV without punctures (Figs. 146, 151) [1 Australian sp.]................................................................................................. Ausogeocoris

-. Body subflat above; pronotal margins only slightly carinate but not explanate; most of corium not densely and uniformly puncate; spiracle II dorsal; abdominal sterna III and IV sub-laterally with a few coarse punctures (Figs. 119) [1 Australian sp.]............................................................................................. Capitostylus

4. Labial segment 2 shorter than 3; ocular suture short, not extending to tip of head; hemelytra coleopteroid or macropterous-submacropterous; clavus in macropters gradually narrowing from base to an apical point, without a claval commissure; scutellum with weakly or feebly developed Y or T median elevation [7 Australian spp.]................................ Geocoris

-. Labial segment 2 and 3 subequal; ocular suture long, clearly reaching tip of head; hemelytra macropterous; clavus almost parallel for entire length, usually with a distinct claval commissure; scutellum with a well developed Y or T median elevation.... 5

5. Abdominal terga III & IV impunctate (Fig. 4); male gonoporal process variable in length; spermathecal duct short or long, usually with coils (Fig. 6) [6 Australian spp.].......................................................... Germalus

-. Abdominal terga III & IV punctate; male gonoporal process short; spermathecal duct short, without coils [5 Australian spp.]........................................................................................... Stylogeocoris