Vatellus

Braga, Rafael Benzi & Ferreira-Jr, Nelson, 2016, Vatellini Sharp (Coleoptera, Dytiscidae) from Brazil: two new species, new records, and a checklist, Zootaxa 4111 (1), pp. 77-91 : 85-86

New steps for Miller’s (2005) key to Vatellus species

Replace the first two steps of the key as here below

1. Anterior clypeal margin anteriorly produced into distinct rim; body dorsoventrally flattened; elytra smooth and shiny between

punctures or with very fine shagrination as on pronotum..................................................... 1a 1`. Anterior clypeal margin not or only weakly produced into rim; body variable, but many species not dorsoventrally flattened;

elytra of most species with surface microreticulation in various forms, or a few species or specimens smooth and shiny

between punctures.....................................................................................6 1a. Anteromedial process of metaventrito not ventrally produced; dorsal surface of pronotum without distinct pattern of shagrina-

tion and punctation....................................................................................2 1a`Anteromedial process of metaventrito of most species ventrally produced into distinct tumidity; dorsal surface of pronotum

usually with fine shagrination between punctures except for smooth, shiny, impunctate area medially on each side of midline

................................................................................................... 2a 2. Ventral surface of dorsal margin of orifice of speleum bilobed with a cavity that receives a corresponding longitudinal, carinate

prominence on the dorsal surface of the ventral margin, dorsal lobe of orifice extremely thick and with an apical, posteriorly

directed; speleum without an enlargement in the middle of its length; males without a well-developed mesotibial tuft of setae

..................................................................................... V. ventralis (Sharp) 2`. Ventral surface of dorsal margin of orifice of speleum almost shallow and ronded, without cavity or carina; speleum with an

enlargement in the middle of its length; males with a well-developed mesotibial tuft................. .. V. caissara sp. nov.

2a. Size very large, TL = 6.6–7.2 mm; speleum abruptly narrowed at the apex; male with two setae tufts on mesotrocanther........................................................................................ V. yanomami sp. nov. 2a`. Size generally smaller, TL <6.6 mm; speleum not abruptly narrowed at the apex; male with one setae tuft on mesotrocanther.................................................................................................... 3