The New International Encyclopædia/Rhizocephala

RHIZ′OCEPH′ALA (Neo-Lat. nom. pl., Gk. ῥίζοκέφαλος, rhizokephalos, having the flower growing immediately from the root, from ῥίζα, rhiza, root + κεφαλή, kephalē, head). An order of most degraded cirripeds, the root-barnacles, especially of the genera Sacculina and Peltogaster. The few forms known are parasitic on the abdomens of various crabs.