Genus Siphona Meigen

undetermined species 1 (J.E. O’Hara pers. comm.).

Distribution. Not determined. Galápagos: Isabela, San Cristóbal, Santa Cruz, Santiago.

Material examined. Galápagos: Isabela: Sierra Negra, 1000 m, sweeping pamp, 3–11.ii.1989, B.J. Sinclair (4 ♁, 3 ♀, CNC). San Cristóbal: La Toma, stream-riparian sweeping, 15.ii.1989, B.J. Sinclair (1 ♀, CNC). Santa Cruz: 1 kmS Media Luna, Miconia, sweeping, 550 m, 21.i.1989, B.J. Sinclair (3 ♁, 1 ♀, CNC). Santiago: Aguacate Camp, 550 m, mossy forest, MT, 7–13.iv.1992, S.B. Peck (1 ♁, CNC) .

Remarks. Adults of this species are confined to highland humid zones. An undetermined species of Siphona has also been observed visiting flowers of Miconia and Pernettya (Boada 2005) .

undetermined species 2 (J.E. O’Hara pers. comm.).

Distribution. Not determined. Galápagos: San Cristóbal, Santa Cruz, Santiago.

Material examined. Galápagos: San Cristóbal: Cerro Mundo, guava thicket, 550 m, FIT, 13–23.ii.1989, S.B. Peck & B.J. Sinclair (1 ♀, CNC). Santa Cruz: Los Gemelos, 600 m, Scalesia fores, sweeping , 25.ii.1989, B.J. Sinclair (3 ♁, CNC). Santiago: Aguacate Camp, 550 m, mossy forest, MT, 7–13.iv.1992, S.B. Peck (1 ♀, CNC) .

Remarks. Adults of this species are confined to highland humid zones.