Key to the species of Nothopleurus

1. Length of ventrite V less than 0.3 times the basal width. Male .................................................................................. 2

- Length of ventrite V greater than 0.4 times the basal width. Female.......................................................................... 5

2(1). Dorsal carina of mandible strongly elevated at basal half, forming a subacute tooth ............................ N. subsulcatus

- Dorsal carina not forming a subacute tooth at basal half ............................................................................................ 3

3(2). Mandibles shorter than head; lateral outer face of mandible strongly tumid; hypostomal area with a plate, parallel to the hypostomal carina ............................................................................................................................... N. madericus

- Mandibles, usually, longer than head; lateral outer face of mandible not strongly tumid; hypostomal area without plate parallel to the hypostomal carina ........................................................................................................................4

4(3). Mandible of major male (usually longer than 40 mm) not notably narrowed at apical fourth (Fig. 36), inner face dis- tinctly oblique, in general, more or less concave; outer face of mandible of minor male distinctly tumid................... ................................................................................................................................................................... N. castaneus

- Mandible of major male (usually longer than 40 mm) notably narrowed at apical fourth (Fig. 38), inner face almost vertical; outer face of mandible of minor male not notably narrowed ....................................................... N. lobigenis

5(1). Dorsal carina of mandible strongly elevated at basal half (Fig.42).............................................................................6

- Dorsal carina of mandible not strongly elevated at basal half (Figs. 37, 39) .............................................................. 7

6(5). Hypostomal area with a plate parallel to the hypostomal carina .............................................................. N. madericus

- Hypostomal area without plate parallel to the hypostomal carina .......................................................... N. subsulcatus

7(5). Outer face of mandible tumid with the general appearance of dorsal carina, in dorsal view, wide .......... N. castaneus

- Outer face of mandible more straight with the general appearance of dorsal carina, in dorsal view, not wide ............ .................................................................................................................................................................... N. lobigenis