(n. pl.) A division of Annelida which includes the genus Echiurus and allies. They are often classed among the Gephyrea, and called the armed Gephyreans.

C Chilopoda Chordata Echiuroidea Ectoprocta Entoprocta Monoplacophora Nemertinea Phoronidea arachnid arthropod beetle bicentenary bicentennial bug caterpillar cental centare centenarian centenary centennial centennium centigram centimeter centistere centred centref centrev centumvir centumvirate centurion century chilopod cwt daddy longlegs diplopod fly gross harvestman hecatomb hexapod hundred hundredweight insect larva long hundred maggot millepede millipede mite nymph one C scorpion sesquicentenary sesquicentennial spider tarantula tercentenary tercentennial tick