Calohelcon obscuripennis Turner is redescribed and illustrated for the first time. Calohelcon roddi n.sp. from New South Wales is described, illustrated and differentiated from C. obscuripennis. The hindwing of C. roddi possesses a distinct transverse vein m-cu, a feature unknown in any other Helconinae but present in many members of the "cyclostome" subfamilies Doryctinae and Rogadinae, and in the apparently related Alysiinae, Betylobraconinae, Gnamptodontinae, Histeromerinae, Opiinae and Telengaiinae. The presence of hindwing vein m-cu is interpreted as a plesiomorphous character state in the "cyclostome" assemblage, but it is suggested that the presence of m-cu in some Calohelcon, represents a re-expression of genetic information, the expression of which had been previously suppressed. The phylogenetic significance of a number of other features of Calohelcon, and of Helconinae in general, are discussed.