A new genus and species of Planorbidae (Gastropoda : Heterobranchia : Pulmonata) from Northern Australia

A new genus and species of Planorbidae, Kessneria papillosa n.gen, and sp, from the Northern Territory. Australia, are described. The new genus is mor phologically most similar to Leichhardtia. another genus restricted to Nort hern Australia, from which it differs in a number of important shell and an atomical characters. The shell of the new genus differs from all other plan orbids in having a raised. papillate protoconch, and is also unique amongst Australian high-spired genera in being umbilicate and in having a sinuate outer lip.