Cytogenetic analysis of ovarian nurse cell polytene chromosomes has revealed the existence of three biological species within the taxonomic species Anopheles marshallii. Composite photographic maps of the sex chromosomes of the three species are presented detailing the fixed rearrangements which have accompanied the evolution of the group. Details of the sites of collection of the new species are also included. Two of the species have been recorded from Salisbury, Zimbabwe, the type locality of A. marshallii.