There is no type species as a new genus was not intended by Hrabe. Note that the lack of a type species automatically makes 'Tubificidarum' an unavailable name as a genus (which it is not - it is an indicative label). All genera named after 1930 must have a type species fixed.
Hrabĕ, S. (1958). Die Oligochaeten aus den Seen Dojran und Skadar. <em>Spisy vydav. Přir. Fak. Masaryk Univ.</em> 397: 337-353. Available for editors [request]