Oxus hastata (Lundblad, 1954)
Synonym: Frontipoda hastata Lundblad, 1954 (original designation)
Type material: Holotype Lundblad No. Präp. 4457, deposited in NRM (Lundblad 1956).
Type locality: Portugal: Beira Alta, in Santa Comba Dão (Lundblad 1954, 1956).
Geographical distribution: Portugal: Beira Alta, in Santa Comba Dão (Lundblad 1954, 1956).
Distribution in Portugal: Centre: Beira Alta, in Santa Comba Dão (Lundblad 1954, 1956).
Ecological notes: Freshwater, at slow-moderate flowing streams, remarkably on a sandy substrate; present in Carex spp. plants (Lundblad 1956).
Remarks: Since Frontipoda Koenike, 1891 is a synonym with Oxus Kramer, 1877 (Besch 1964), we recommend Frontipoda hastata Lundblad, 1954 as a junior synonym with Oxus hastata (Lundblad, 1954) .
Oxus lusitanicus Lundblad, 1954
Type material: Holotype (Lundblad 1954), Lundblad No. Präp. 4456, deposited in NRM (Lundblad 1956).
Type locality: Portugal: Beira Alta (Valdecasas 1988), Côa River (Lundblad 1954), near 10 km to Vilar Formoso (Lundblad 1956).
Geographical distribution: Portugal: Beira Alta (Valdecasas 1988), Côa River (Lundblad 1954), near 10 km to Vilar Formoso (Lundblad 1956).
Distribution in Portugal: Centre: Beira Alta (Valdecasas 1988), Côa River (Lundblad 1954), near 10 km to Vilar Formoso (Lundblad 1956).
Ecological notes: Freshwater, at the riverine clear water, present in Myriophyllum spp. and Juncus spp. (Lundblad 1956) .
Oxus oblongus Kramer, 1879
Type material: Holotype (Kramer 1879), possibly not deposited in any scientific collection.
Type locality: Germany: Schleusingen (Kramer 1879) .
Geographical distribution: Germany (Kramer 1879),
Distribution in Portugal: Centre: Beira Litoral, in Alcabaça municipality; South: Estremadura, in Sintra-Monserrate Park and Palace (Lundblad 1956; Valdecasas 1988).
Ecological notes: Freshwater, at temporary pond waters and slow-moderate motion streams (Lundblad 1956).
Remarks: When Lundblad described the specimens he found in Portugal, Spain and France he emphasized that they could be aberrant forms, similar to Oxus oblongus (Lundblad 1956) . Later Oxus oblongus was mentioned as a possible synonym of Oxus strigatus (Di Sabatino et al. 2010; Smit & Gerecke 2010) but this has not been fully clarified either.