Tritogenia zuluensis (Beddard, 1907) is re-described and the taxonomic position of this species is verified. Limited knowledge of South African earthworms at the time of the original species description and a misleading specimen illustration led to difficulty in the establishment of its true identity. Thanks to protection of the type material at the Natural History Museum, University of Oslo, Norway, this species can be redescribed and illustrated, and its lectotype and paralectotype are designated. Types of Microchaetus zulu Michaelsen, 1907, a junior synonym of Tritogenia zuluensis, safely stored for more than a hundred years in the Göteborg Natural History Museum, Sweden, was most helpful in the process of re-description. The significant role played by museums and similar organizations in protecting past and present natural resource treasures for the future, is highlighted. The crucial function of natural history collections in supporting traditional taxonomy, the key to understanding biodiversity, is clearly demonstrated.