Abstract
During the early period of the study of microsporidia (now phylum Microspora) simple morphological features, in particular the number of spores produced by each sporoblast, were used to define genera. This led to the assemblage in genera of parasites, which when their developmental characters and host/parasite relationships were examined, could not be considered to be closely related. The Workshop was convened in Order to discuss the relative value of characters used for defining genera and to investigate selected problems of generic segregation and aggregation in representative classes. It was hoped to expose some of the inadequacies in the present methods and make recommendations for generic definitions which would form the basis of a taxonomic System, itself reflecting the phylogeny of the group.