[Crustacea] (Abbr.) Coxa: the first (basal) podomere of the protopodite.[Copepoda] (Fig. Co.1d , Md mandible , Fig. Co.1e , Mxp maxilliped, Fig. Co.1f , Mx1 maxillule, Fig. Co.1g , Mx2 maxilla, Fig. Co.2 , Swimming leg.