the nomenclature of genera has been one of the most confusing issues in the lymnaeidae systematics. most genus names are not fixed and are based more on phenotypic resemblances than on sound evolutionary and phylogenetic considerations. for instance, a single genus in lymnaeidae was recognized by walter (1968), two by hubendick (1951), and up to 34 genera by others. results by correa et al. (2010) indicate that genera in lymnaeidae do not reflect phylogenetic relationships, to the notable exception of "radix" (including "radix natalensis").