Subfamily Monochromadorinae Andrássy, 1958
Udonchinae Eyualem & Coomans, 1996: 213.
Diagnosis
Cheilostom with twelve longitudinal rugae; stoma with three denticles, which are arranged in two separate groups at two levels; female reproductive system monodelphic.
Type and only genus
Udonchus Cobb, 1937 .