The original description of the monotypic genus UncinalaRuckes, 1965 is complemented. The so far unknown female of U. tau Ruckes, 1965 is described; illustrations and descriptions of the external and internal genitalia are given. Illustrations are provided for the male structures that taken together make U. tau a remarkable discocephaline species: the extremely ornate pygophore, the unusual apex of the corium and membrane of the hemelytrum, the abdominal stridulitrum and, also, the median process of the posterior margin of the seventh tergite. Descriptions are provided for the pygophore and phallus which is also illustrated. New locality records are given for U. tau.