Description of two new species of the Exocelina broschii-group from Papua New Guinea, with revision and key to all representatives of this species group (Coleoptera, Dytiscidae, Copelatinae)

Abstract. Two new species of Exocelina Broun, 1886 from Papua New Guinea are described herein: Exocelina mondmillensis sp. n. and Exocelina pseudomarinae sp. n. They are placed into the Exocelina broschii-group based on the shovel/fork-like ventral sclerites of their median lobe. While the former has rather distinct combination of the morphological characters (inconspicuous dorsal punctation, thin apex of the median lobe and ventral sclerite of the median lobe with two tips of different length), the latter is very similar to already described species Exocelina marinae (Shaverdo, Sagata & Balke, 2005). All described species of the group are revised and a key to their identification is provided. Important diagnostic characters (habitus, color, protarsomeres 4–5, median lobes, and parameres) are illustrated. Data on the distribution of all species of the group are given showing that its representatives occur only in Papua New Guinea and most of them are widely distributed in it central part.