Maileus is a monotypic genus of jumping spiders containing the single species, Maileus fuscus. It was first described by G. Peckham & Elizabeth Peckham in 1907,[1] and is only found on Borneo.[2] It is closely related to the genus Microhasarius.
M. fuscus is known only from a single female, which is about long. Although no published drawings exist, Zabka has drawn the genitalia, and Proszynski has drawn the genitalia of both sexes of what is probably a different species of Maileus.[3] No study has been published on the genus since its first description.
The species name is derived from Latin fuscus "dusky, brown".