Family Diagnosis. Copepoda parasitic dorsally on Polynoid Worms.Female with body divided into cephalothorax (head and neck) and trunk. No appendages articulated or otherwise on head or neck. No traces of segmentation. No mouth nor alimentary canal. Cuticle thin. Head and neck buried in the tissues of the host; the head converted into a voluminous organ whose only function is to absorb nutritive materials by endosmosis through expansions or rootlets. Head and neck at right angles to the middle of the trunk. A chitinous ring is usually present at the base of the neck at its insertion on the trunk. Genital apertures wide, the pyriform eggstrings issuing therefrom.