Developmental stages of thoracic chaetotaxy of Protaphorura armata (Tullberg, 1869) sensu Gisin, 1952, 1960, and of P. furcifera (Börner, 1901) are analysed. The chaetotaxy of the first juvenile stage is identical in both species and oligochaetose, it closely resembles the chaetotaxy found in most Hypogastruridae. The plurichaetose condition, typical of the genus Protaphorura, is developed by a gradual orderly appearance of supplementary setae, among which the primary setae still can be recognized.