A species-group key and notes on phylogeny and character evolution in New Guinean Exocelina Broun, 1886 diving beetles (Coleoptera, Dytiscidae, Copelatinae).

Detailed information about the known species groups of Exocelina Broun, 1886 from New Guinea is presented, including species numbers, distribution, and references of species-group diagnoses, keys to the species, and species descriptions. An identification key to all species groups is provided. Phylogeny and morphological character evolution are discussed.