Genus Pseudeucinetus Heller, 1921 Pseudeucinetus Heller, 1921: 155 (type species: Pseudeucinetus zygops Heller, 1921). Thaumastodus Champion, 1924a: 25 (type species: Thaumastodus fusiformis Champion, 1924; synonymized by Champion 1924b). Pseudeucinetus – Satô 1994: 173. — Spangler 1995: 395. Diagnosis Body oblong. Gena wide; shallow antennal groove present.Frons (Fig. 2 E–F) narrow, distinctly projecting anteriorly. Antennae stout and short, 11-segmented; antennal insertions situated near mandibles. Legs relatively short and stout; tarsal formula 4-4-4; male fore tarsi enlarged (Fig. 3E). Remarks This genus is easily distinguishable from other genera of the subfamily Thaumastodinae by the unique shape of the head: frons distinctly projecting anteriorly and narrow between the eyes. Biological notes The habitat of this genus (Fig. 4A) is freshwater environments, i.e., rivers and streams. The adults are found in the splash zone of wet rocks, and frequently actively flying. In Java, Indonesia, Pseudeucinetus javanicus and Acontosceles javanicus were collected in the same place (Yoshitomi & Putra 2011). The adults were also collected by light trap. The larval stages are unknown. Key to the males of the species of Pseudeucinetus (modified from Yoshitomi & Putra 2010) 1. Lateral lobes with a pair of small projections on inner margins........................................................ 2 – Lateral lobes without any projections on inner margin ..................................................................... 4 2. Subbasal inner projections of lateral lobes distinct and acute; basal piece short, about 0.5 times as long as lateral lobe............................................................................ P. novabritannica Delève, 1973 – Subbasal inner projections of lateral lobes absent; basal piece long, about 0.7–0.8 times as long as lateral lobe ......................................................................................................................................... 3 3. Subapical inner projections of lateral lobes small and obvious.......................... P. papuanus sp. nov. – Subapical inner projections of lateral lobes large and distinct ............................................................ ............................................................................................ P. solomonicus Yoshitomi & Putra, 2010 4. Apex of median lobe of aedeagus acuminate in dorsal or ventral view ............................................ 5 – Apex of median lobe of aedeagus nipple-like in dorsal or ventral view .. P. spilmani Spangler, 1995 5. Median lobe strongly pointed at apex, straight on lateral margins; basal piece gently curved dorsally ............................................................................................................. P. zygops Heller, 1921 – Median lobe weakly pointed at apex, arcuate on lateral margins; basal piece strongly curved dorsally .............................................................................................................................................. 6 6. Apices of lateral lobes straight, acute; median lobe widest at the middle..... P. uenoi Spangler, 1995 – Apices of lateral lobes obtuse; median lobe widest at basal part ........................................................ ................................................................................................. P. javanicus Yoshitomi & Putra, 2010

Published as part of Yoshitomi, Hiroyuki, 2019, Review of the Asian Thaumastodinae (Coleoptera, Byrrhoidea, Limnichidae), with a phylogeny of the genera, pp. 1-45 in European Journal of Taxonomy 583 on pages 14-15, DOI: 10.5852/ejt.2019.583, http://zenodo.org/record/3564532