A new species, Gnathia nkulu sp. n. is described from material collected off the South African coast at 80-200m depth. It differs from the intertidal species Gnathia africana Barnard, 1914 in that the mediofrontal process is not deeply divided into two lobes, article 2 of the pylopod is rounded and small wart-like tubercles and long simple setae are present on both the cephalosome and pereon.
A redescription of the adult male and praniza of Gnathia africana Barnard, 1914 is provided from material collected at three localities along the South African coast and from syntypes and other material deposited by the original author. This redescription is based on light and scanning electron microscopy.
A redescription of the adult male of Caecognathia cryptopais (Barnard, 1925) is provided from syntypes and other material deposited in the South African Museum. The generic status of Caecognathia cryptopais is also revised. This redescriplion is based on light and scanning electron microscopy.