Couplet 188

188a:  Antenna filiform; terminal labial and maxillary palpomeres expanded apically; prosternum shorter than diameter of fore coxa; mid tibial spurs pubescent or serrate; tarsi lobed on penultimate tarsomeres (Osphyinae)

Melandryidae   p. 434

188b:  Antenna with long, serrate club formed of last 3 antennomeres; terminal labial and maxillary palpomeres cylindrical; prosternum as long as fore coxal diameter; mid tibial spurs smooth; tarsi not lobed (Trimitomerus)