Key to genera of Systellopini (males only) (modified from Allsopp 1990) 1 Antennal club with 3 long lamellae (Figs. 1–2); labrum fused with clypeus dorsally (visible only at lateral declivity) (Figs. 4–5); clypeus widest at base, non-emarginate before ocular canthus (Figs. 4–5)..................................................................................................... Liomenochilus Hutchinson & Allsopp, new genus - Antennal club with 5, 6 or 7 long lamellae (Figs. 19–24); labrum clearly separated from clypeus by a suture (Figs. 19–24); clypeus constricted at base (Figs. 19–24)................................................................... 2 2 Lamellae of antennal club fringed with long, pilose filaments (Figs. 18, 22).............. Sarothromerus Blackburn, 1907 - Lamellae of antennal club setose or glabrous (Figs. 19–21, 23–24).............................................. 3 3 Labrum short, length:width ratio 0.3:1 (Figs. 12–16, 19–21, 23); metafemora less strongly dilated, length:width ratio> 1.4:1............................................................................................... 4 4 Antennal club with 5 lamellae, inner faces of lamellae glabrous................................................. 5 - Antennal club with 5, 6 or 7 lamellae, inner faces of lamellae setose............................................. 6 5 Canthus at level of middle of eye, frons narrow (Figs. 12, 19); dorsal labrum with transverse ridge dividing rugose anterior third from smooth posterior portion (Fig. 19); posterior portion of epipleurae spinose (Fig. 12); disc of pronotum glabrous (Figs. 12, 19).............................................................................. Chilodiplus Sharp, 1877 - Canthus well above level of middle of eye, frons wide (Figs. 16, 23); dorsal labrum with reflexed anterior and lateral margins forming a continuous ridge (Fig. 23); posterior portion of epipleurae without spines (Fig. 16); disc of pronotum setose (Figs. 16, 23)........................................................................... Sphyrocallus Sharp, 1877 6 Disc of pronotum glabrous (Figs. 14, 21), antennal club with 5 or 6 lamellae................. Prochelyna Erichson, 1847 - Disc of pronotum at least with patch of setae in anterolateral angles, usually across entire pronotal disc but possibly effaced (Figs. 13, 20); antennal club with 5, 6 or 7 lamellae........................................ Enamillus Sharp, 1877

Published as part of Hutchinson, Paul M. & Allsopp, Peter G., 2022, Liomenochilus ongi (Coleoptera: Scarabaeidae: Melolonthinae: Systellopini), a new genus and new species from northern Western Australia, pp. 119-128 in Zootaxa 5100 (1) on page 124, DOI: 10.11646/zootaxa.5100.1.6, http://zenodo.org/record/6127852