Morphological comparisons of populations of Filinia from New Zealand and Australia established the presence of an undescribed species in Lake Okaro, N.Z. Filinia novaezealandiae n. sp. is described. SEM micrographs of trophi were used to distinguish closely allied Filinia species. Filinia grandis comb. nov. is redescribed from Australia on the basis of trophi differences from F. pejleri. It is suggested that Filinia species may be more restricted than global records indicate; these records reflect the distribution of authoritative taxonomic references, not necessarily the animals they depict.