Taxonomy of the Proisotoma complex. VI. Rediscovery of the genus Bagnallella Salmon, 1951 and epitoky in Bagnallella davidi (Barra, 2001), comb. nov. from South Africa

The genus Bagnallella Salmon is restored and given a diagnosis. It takes an intermediate position between Proisotoma Börner and Cryptopygus Willem complexes and is characterized by the separation of the two last abdominal segments (like in Proisotoma) and 3 and 5 s-chaetae on the fourth and fifth abdominal segments (like in Cryptopygus and its allies). A list of and key to species belonging to Bagnallella is given. Bagnallella bisetacomb. nov., B. dubiacomb. nov., B. sedecimoculatacomb. nov., and B. tenellacomb. nov. are commented and redescribed. Morphology of Bagnallella davidi (Barra), comb. nov. is described from the specimens from South Africa. So far B. davidi appears to be a complex of forms differing in size of the furca and macrochaetae. Two types of strongly modified males were found and described. Antennae, ventral side of abdomen, posterior edge of abdominal tergites, and mandibles are affected with epitoky. The nature of the discovered strong polymorphism is unclear.