Elachiptera cultrata sp. nov. is described from the Galápagos Islands, Ecuador. This species is most similar to the northern Neotropical species E. attenuata (Adams), except for the shape of the arista and the male genitalia. The monotypic genus Ceratobarys is synonymized with Elachiptera, and its type species C. eulophus (Loew) transferred to Elachiptera as E. eulophus comb. nov. The only morphological character that distinguishes the two genera is the presence of a long, apical, hind-tibial spur in Ceratobarys. Although this character defines some apparently monophyletic genera of Chloropidae, its presence and size are subject to homoplasy in other genera. The presence of a small hind-tibial spur in some species of Elachiptera, and the great similarity in other external and genitalic characters between Ceratobarys and some species of Elachiptera makes recognition of Ceratobarys untenable.