de Haan, 1839
P5 always dorsal, very mobile, generally (except for the family Poupiniidae) reduced in length and width, and with a special terminal subchelate or chelate apparatus (except for the family Poupiniidae and a few Latreilliidae). In both sexes uropods never present. First pair of pleopods absent in females. Spermathecal apertures not rounded, oblique. Male abdomen with six distinct segments plus the telson. Absence of a true sterno-abdominal cavity. Retaining mechanism of the abdomen complex, especially with "homolian press-button". Male Pl 1 tubular and closed; male Pl 2 about of the same length as the Pl 1, cylindrical, not tapering, never with a long styliform flagellum. (Guinot 1998)
Families treated:
family Homolidae de Haan, 1839
family Latreilliidae Stimpson, 1858