Diagnosis
Anterior of carapace rounded in lateral view, with the incisure either totally lacking or only very shallow. The carapace of males is generally more elongate, but shorter then that of the females, and with greater expression of the incisure. The ornamentation of the carapace varies between species but is similar in the two sexes. There is ususally a well-developed caudal process. The first antenna has the third and fourth segments fused, and the sensory seta on the female5th segment is either bare or carries 2-3 short filaments. In the males this seta has numerous filaments. The endopodite of the female second antenna is either one or two segmented. In males it may either have a single segment or three in which case the third segment is strongly reflexed on the second. The numbers of hook setae on the caudal furca vary from 5 to 9. The frontal organ is elongate or short and conical.
Remarks
There are now sixteen genera described in this family and Kornicker, 1975 gives a full diagnosis.