Subclass Copepoda Milne-Edwards, 1840
Copepods at some stage in their life-cycle possess at least 2 pairs of swimming legs with rami connected by an intercoxal sclerite; a Ce into which the Mxp bearing somite is incorporated; uniramous A1 with up to 27 segments, although in many copepods (harpacticoids) the segmentation of A1 is secondarily reduced; possess egg-sacs, although some important groups lack true egg-sacs and they are secondarily lost in some highly derived parasitic forms.
Huys et al., 1996