One hundred and five specimens of flies belonging to this family were collected. They belong to two species which are described below.
Although in the past New Zealand Canaceids have been regarded as belonging to a sub-family of the Ephydridae (Tonnoir and Malloch, 1926), the group is here regarded as of true family rank because of several important characters which separate it from the rest of the Ephydridae. Chief among these characters are: absence of a costal break near the humeral cross vein, presence of an anal cell, separation of the second basal and discal cells and separation of the auxiliary and first longitudinal vein.
Genus Macrocanace Tonnoir and Malloch
Tonnoir and Malloch, 1926, Rec. Cant. Mus. 3, 5.
Genotype: Macrocanace littorea Tonnoir and Malloch 1926 = Milichia littorea Hutton 1901.
The genus Macrocanace, known only from the sub-Antarctic islands of New Zealand, contains only two described species. They are M. littorea from Antipodes Island and M. australis (Hutt.) from Campbell Island. One new species was collected by the 1950 expedition, and this is described below under the name of M. antipoda.
The three known species of the genus Macrocanace can be separated readily by the following key.