GENUS MELANOSTOMA Schiner

Plesia Macquart 1850: 460. Type-species: Plesia fasciata Macquart, 1850, original designation [Preoccupied by Jurine, 1807]

MELANOSTOMA Schiner 1860: 213. Type-species: Musca mellina Linnaeus, 1758, original designation.

Most authors (cf. Hull 1949a: 332) have overlooked Macquart's designation of fasciata as the type of his genus, and have used the name Plesia as if based on the other included species, anale Macquart. Plesia anale is related to Chrysogaster (subfamily Eristalinae, tribe Brachyopini) and will be designated the type of a new genus. Fortunately, the name Plesia is preoccupied and, therefore, will not supplant the well-known name Melanostoma.

fasciatum Macquart, 1850: 461 (Plesia fasciata). apertum Hutton, 1901: 42.

? scalare, Miller, 1950, not Fabricius, misidentitication.

Melanostoma apertum Hutton was described from a unique female from Christchurch, which Hutton stated to have "unfortunately, lost the antennae." Miller (1921: 308) examined the holotype, noting that part of the antennae remained, and wrote "owing to the length of the existing 2nd joint [of the antenna], it is doubtful if this species belongs to Melanostoma." Of the second antennal segment, Miller wrote the "2nd joint elongate, reaching toward the facial prominence." The holotype is now without a head, so it is impossible to verify Miller's statements. However, the holotype otherwise is in fair condition and is a melanistic specimen of the common fasciatum.

Miller (1950: 96, 144) listed a species, scalare, as separate from fasciatum and as introduced from Europe. I can not confirm this as I have seen no specimens of scalare and suspect Miller may have confused the female of fasciatum with scalare. True scalare from Europe is a much larger species, but the females of the two have almost identical color patterns.