226a (225a).    Brood-passage opening a narrow, linear or oblong slit; thorax
prominent
...............................................................................….................….......(Strepsiptera)  Halictophagidae
 
 
226b.    Brood-passage opening broad and semicircular; thorax reduced
and ring-like in back of
                             brood-passage
opening..................................................………....................(Strepsiptera)  Elenchidae