Protozantaena, Perkins, 1997

Perkins, Philip D., 2009, Revisions of the genera Parhydraena Orchymont, Protozantaena Perkins, Decarthrocerus Orchymont, and Parhydraenopsis nomen novum, aquatic and humicolous beetles from Africa and Madagascar, and comparative morphology of the tribe Parhydraenini (Coleoptera: Hydraenidae), Zootaxa 2038, pp. 1-119 : 13

Key to species of Protozantaena

1 Maxillary palpi comparatively long, palpus length/head width ratio ca. 0.64–0.72..................................................... 2

- Maxillary palpi comparatively short, palpus length/head width ratio ca. 0.41–0.55 .................................................. 3

2 Pronotum wider apically than basally; pronotal discal interstices smooth and shining; last maxillary palpomere wide subbasally, abruptly narrowed basally on anterior surface; Namibia; aedeagus as illustrated ( Figs. 67, 69) ................ ............................................................................................................................................................... labrata Perkins

- Pronotum narrower apically than basally; pronotal discal interstices microreticulate, dull; last maxillary palpomere not distinctly widened; Madagascar; aedeagus as illustrated ( Figs. 71, 73) ........................................... palpalis n. sp.

3 Elytral series on disc weakly striate-impressed; maxillary palpi and tarsi very short, palpus length/head width ratio ca. 0.41; Tanzania; aedeagus as illustrated (Figs. 75,77) ................................................................ grebennikovi n. sp.

- Elytral series not striate-impressed; maxillary palpi and tarsi longer, palpus length/head width ratio ca. 0.47–0.55; Madagascar.................................................................................................................................................................. 4

4 Pronotum lateral margins each a single thin rim in lateral view; pronotal disc less coarsely punctate; metaventrite of males with median groove bordered on each side with pubescent carina; smaller species, length ca. 1.35 mm; aedeagus as illustrated ( Figs. 68, 70) ................................................................................................ malagasica n. sp.

- Pronotum lateral margins dual-rimmed from anterior angles to about midlength; pronotal disc more coarsely and densely punctate; metaventrite of males unmodified; larger species, length ca. 1.73 mm; aedeagus as illustrated ( Figs. 72, 74) ........................................................................................................................................ ankaratra n. sp.