Descriptions of two new species of Quasithelazia Maplestone, 1932 (Spirurida: Acuariidae) and a redescription of Alinema sturni Jögis, 1968 from birds in Australia.

Quasithelazia minuta n. sp. and Quasithelazia pearsoni n. sp. (Spirurida: Acuariidae) are described from Todiramphus sanctus (Vigors & Horsfield) (Coraciiformes: Alcedinidae) in Australia. Alinema sturni Jögis, 1968 from Sturnus vulgaris (L.) (Passeriformes: Sturnidae) in Europe, is considered to belong in the subfamily Schistorophinae Travassos, 1918 (and not in the Seuratiinae Chitwood & Wehr, 1932, where it has previously been placed) on the basis of the number of the pairs of precloacal papillae. The latter species, known from its original record only, is found as parasitic in diverse passerine birds in Australia, namely Psophodes olivaceus (Latham) (Psophodidae), Falcunculus frontatus (Latham) (Pachycephalidae), Colluricincla harmonica (Latham) (Pachycephalidae), Malurus cyaneus (Ellis) (Maluridae) and Ptilotula penicillata (Gould) (Meliphagidae). Alinema sturni is considered an alien species for Australia that has been introduced with its host (starling) and subsequently adapted to a wide range of native avian hosts.