Redescription of Archegozetes magnus (SELLINICK, 1925) (Trhypo- chthonioidea) from Brazil and description of two new species of nanhermanniid mites: Bicyrthermannia nigeriana and Masthermannia seropedica (Nanhermannioidea) (Acari: Oribatida)

This paper is the second in a series of investigations on desmonomatid mites collected from Nigeria and Brazil. Two morphological forms of a trhypochtoniid species, Archegozetes magnus (SELLINICK, 1925) from Brazil was redescribed. One shares similar features with A. magnus which was originally described from Sumatra while the other shares morphological features with a subspecies, A. magnus mediosetosus from Seychelles. These different morphological forms are regarded as mere variations within the populations of this highly thelytokous species, and the creation of subspecies was considered as unnecessary. A. veracruensis is sunk as a synonym of A. longisetosus which is in turn seen as another morphological form of A. magnus which was not present in the site investigated. The geographical distribution of Archegozetes was reported and it was observed that this genus is restricted to islands, coastal and inland areas close to big rivers in neotropical, Pacific and oriental regions. Two species of the family Nanhermanniidae belonging to different genera are also described. Bicyrthermannia nigeriana was described from Nigeria and Masthermannia seropedica was described from Brazil. The significant differences between each of these species and the type and related species in their respective genera were highlighted. Inadequate and/or incomplete description of many species in literature was observed as a major constraint when comparing new species with existing ones.