Male Nihoan trapdoor spiders (N. hawaiiensis) grow to almost 15 millimetres (0.59 in) long, including
chelicerae. The females are larger, growing up to 21 millimetres (0.83 in).[3]
Species
As of April 2019[update] it contains twenty-three species:[1]
^Churchill, T. B.; Raven, R. J. (1992). "Systematics of the intertidal trapdoor spider genus Idioctis (Mygalomorphae: Barychelidae) in the western Pacific with a new genus from the northeast". Memoirs of the Queensland Museum. 32: 9–30.