Key to males of Stereocephalus

1. Dorsum of head with two impunctate, polished, medial spots (Herman, 1 9 7 9: fig. 1)…..................3

-. Dorsum of head without impunctate, polished spots (see Herman, 1 9 7 9: figs. 3 8, 4 5)…..............2

2(1). Aedeagus with apex of dorsal sclerite punctate (Figs. 4, 5; Herman, 1 9 7 9: fig. 3 7); Brazil .............. ............................................ S. ruhus Herman, 1 9 7 9

-. Aedeagus with apex of dorsal sclerite deeply bifurcated (Figs. 6, 7; Herman, 1 9 7 9: fig. 4 2); Brazil ...............................… S. myrigeus Herman, 1 9 7 9

3(1). Aedeagus, in lateral view, with ventral sclerite abruptly ascending subapically and with poll picklike or clublike apical ornamentation (Fig. 3).....… …..……............................……....... S. agostii n. sp.

-. Aedeagus, in lateral view, with ventral sclerite gradually or moderately curved to pointed apex (Herman, 1 9 7 9: figs. 1 2, 2 4)…..........................…4

4(3). Ventral sclerite of aedeagus, in ventral view, with slender, pointed apex (Figs. 8, 9; Herman, 1 9 7 9: fig. 1 1)…............ S. seriatipennis Lynch, 1 8 8 4

-. Ventral sclerite of aedeagus, in ventral view, with shallowly emarginate posterior margin (Figs. 1 0– 1 2; Herman, 1 9 7 9: fig. 2 6) ..................................... ....................................... S. rinnanus Herman, 1 9 7 9