Key to the species of Ptilocerus from Australia and Papua New Guinea

1 Corium with basal inner (or posterior) cell about half as long as apical inner (or posterior) cell (Fig. 2a); corium long, occupying more than two fifths of total length of hemelytra (Figs. 1, 2a); membrane with vein M ending near its apical margin (Fig. 2a) (Australia)..................................................................... P. spangenbergi sp. nov.

- Corium with basal inner (or posterior) cell about as long as apical inner (or posterior) cell (Fig. 2b); corium short, occupying about three tenths of total length of hemelytra (Fig. 2b); membrane with vein M ending near its anterior margin (Fig. 2b) (Papua New Guinea)................................................................... P. papuensis sp. nov.