ORIGINAL DESCRIPTION: 1871a: 325.
TYPE LOCALITY: “ In Scandinavia … meridionali & media …; in Scania & Ostrogothia …; in Lapponia Lulensi ad Quickjock femina a D. Boheman … lecta; ex Hafnia Danorum uterque sexus … sub nomine “ A. linogrisea Meig. ” a D. Staeger … (E Lubeca (Lybeck) a D.D. Jac. Behrens & C.J. Milde specimina feminea … missa) [Southern and central Scandinavia; Scania and Östergötland…; female collected by D. Boheman in Lule Lapmark in Kvikkjokk; both sexes in Copenhagen from D. Staeger labeled “ A. linogrisea Meig. ” … (Females from Lübeck collected by D.D. Jac. Behrens and C.J. Milde)]” (Zetterstedt 1845: 1659) [localities for Hydrophoria linogrisea (Meigen, 1826) sensu Zetterstedt (1845)]; “ in Apennino parmensi [Parmese Apennines (Italy)]” (Rondani 1871a: 325) [type locality for Hydrophoria interposita Rondani, 1871].
TYPE MATERIAL: 1 ♀, syntype (missing abdomen, mid- and hind-legs, left wing broken) (MZUF: Box 25): Hydrophoria Desv. / interposita Rndn., linogrisea Mg., Parma / 1364; 1 ♂, syntype (puparium pinned below specimen) (MZLU: Box 29): 136 Anthomyza Zett. / 147 / A. linogrisea a. ♂ a Staeg. [= Staeger] / Type no. 6677: 2; 1 ♂, syntype (missing left mid-leg) (MZLU: Box 29): 136 Anthomyza Zett. / [blue label with 37] / Svec. [= Sweden] / Type no. 6677: 3; 1 ♀, syntype (puparium pinned below specimen) (MZLU: Box 29): 136 Anthomyza Zett. / 148 / A. linogrisea ♀ a. Staeg. [= Staeger] / Type no. 6677: 4; 1 ♀, syntype (MZLU: Box 29): 136 Anthomyza Zett. / Sve. [= Sweden] / Type no. 6677: 5.
CURRENT STATUS: junior synonym of Hydrophoria linogrisea (Meigen, 1826) (Dely-Draskovits 1993: 62, Gorodkov et al. 1995: 7).
REMARKS: Rondani (1871a: 325) proposed Hydrophoria interposita for Hydrophoria linogrisea (Meigen, 1826) sensu Zetterstedt (1845: 1659), which he considered a new species. Rondani referred to Zetterstedt’s redescription of Hydrophoria linogrisea, which was based on an unspecified number of specimens, and to unspecified number of females he collected: “ foeminam tantum … inveni [I found the female only]”. Therefore, the type material is in the collections of Zetterstedt (MZLU) and Rondani (MZUF). Five syntypes were found in this study.