1	Dorsal cirri absent on some chaetigers	2
–	Dorsal cirri on all chaetigers	3
2	Antennae, tentacular cirri and dorsal cirri present on chaetiger 1; appendages absent on other chaetigers. Both simple and compound chaetae present	Procerastea
–	Dorsal cirri absent on chaetigers 2–5. Cirrostyles foliacious. All chaetae simple	Imajimaea
3	Large, clavate, dorsal cirri alternate with much smaller, cylindrical or clavate cirri. Nuchal epaulettes on special outgrowths	Virchowia
–	Not as above	4
4	Reproduction by epigamy	Epigamia
–	Reproduction by schizogamy	5
5	Trepan in two rows. Bayonet chaetae distally thick. Reproduction by anterior scissiparity	Proceraea
–	Trepan in single row. Bayonet chaetae distally slender. Reproduction by gemmiparity or anterior scissiparity	Myrianida