Cethegus fugax is a species of mygalomorph spider in the Euagridae family. It is endemic to Australia. It was described in 1908 by French arachnologist Eugène Simon.[1]
The species occurs in South Australia and Western Australia, in low woodland and open forest habitats, on sandy and gravelly soils. The type locality is Lion Mill (now Mount Helena, a suburb of Perth).[1]
The spiders are fossorial, terrestrial predators. They construct sheet webs against rocks, logs and stumps.[1]