Abstract
Australian galeommatoideans living with valves permanently open at 180° are reviewed, including Ephippodonta and Ephippodontoana species from Yorke Peninsula, South Australia, and three new species belonging in three new genera from New South Wales and Queensland, viz., Ephippodontomorpha hirsutus n. gen. n. sp., collected from stomatopod burrows on the north east coast of Queensland; Troglodytoconcha carpentariensis n. gen. n. sp. found living in a sponge in the Gulf of Carpentaria, and Duoconclavis piscator n. gen. n. sp., from under stones at Long Reef, Sydney. The relationships of galeommatoideans with widely open valves are discussed.