Description of 23 new species of the Exocelina ekari-group from New Guinea, with a key to all representatives of the species group (Coleoptera, Dytiscidae, Copelatinae)

Twenty three new species of Exocelina Broun, 1886 from New Guinea are described herein: Exocelinabewaniensis sp. n., Exocelinabismarckensis sp. n., Exocelinacraterensis sp. n., Exocelinagorokaensis sp. n., Exocelinaherowana sp. n., Exocelinajimiensis sp. n., Exocelinakisli sp. n., Exocelinaksionseki sp. n., Exocelinalembena sp. n., Exocelinamantembu sp. n., Exocelinamichaelensis sp. n., Exocelinapinocchio sp. n., Exocelinapseudoastrophallus sp. n., Exocelinapseudobifida sp. n., Exocelinapseudoedeltraudae sp. n., Exocelinapseudoeme sp. n., Exocelinasandaunensis sp. n., Exocelinasimbaiarea sp. n., Exocelinaskalei sp. n., Exocelinatabubilensis sp. n., Exocelinatariensis sp. n., Exocelinavovai sp. n., and Exocelinawannangensis sp. n. All of them have been found to belong to the Exocelinaekari-group. An identification key to all known species of the group is provided, and important diagnostic characters (habitus, color, male antennae, protarsomeres 4-5, median lobes, and parameres) are illustrated. Data on the distribution of the new species and some already described species are given.