1941] 
Jassoid Genera 
119 
the new combination. The following characters which occur 
in all the Eurymelidae are not found in Idiocerus : in the 
head the epicranial sutures are invariably retained; in the 
tegmen the media has always two, and sometimes three, 
distinct branches; in the male genitalia the aedeagus is not 
in direct contact with the basal plates. Quite apart from 
these features, the Eurymelidae differ from the Idioceridae 
in shape, coloration and habits. Figures of Idiocerus dolosus 
Ball (Fig. 6, d-f), are given for comparison with those of 
Bythoscopus. 
Figure 6. a, Macropsis tasmaniensis ; b, c, Oncopsis distinctus ; 
d-f, Idiocerus dolosus; g-i, Euragallia furculata. 
Jassidae 
Figures are not given of a representative of this family, 
but there seems no good reason why genera such as Jassus 
Fabr. and Tharra Kirk, should be associated with forms 
such as Euscelis and Thamnotettix. 
Thymbridae 
Oman, in referring to Nionia Ball, states that it was cor- 
rectly placed by Ball as a relative of Tartessus Stal, but was 
more closely related to Thymbris Kirk, and Epipsychidion 
Kirk. I have not had an opportunity of examining a speci- 
men of Nionia, but, if it is closely related to Thymbris, it is 
