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) Author Perkins, Philip D. text Zootaxa 2009 2009-03-16 2038 1 119 journal article 1175­5334 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.