Perizoma affinitata(Redirected from Rivulet (moth))
Its wingspan is 24–30 mm. is characterized by the narrow white postmedian band of the forewing and especially by the dark hindwing, with only a narrow, divided white or whitish band. N. and W. Germany, and rather less extreme from England and according to Staudinger it is distributed in Central and Northern Europe and Romania. - rivinata Fisch.-Rossl. has the white on the forewing much extended and the hindwing broadly or almost wholly white. It belongs chiefly to northern or mountain districts, but sometimes occurs as an aberration with the type England, N. Norway, the Alps, Carpathians. - magistraria Trti. and Verity is larger, the forewing grey, not brown, but darker than in hydrata and with broader white band; hindwing greyish with double whitish band; underside like that of rivinata. Terme di Valdieri, Maritime Alps. 
- Fauna Europaea
- Prout , L.B. 1912–16. Geometridae. In A. Seitz (ed.) The Macrolepidoptera of the World. The Palaearctic Geometridae, 4. 479 pp. Alfred Kernen, Stuttgart.