Bouillon, J.; Gravili, C.; Pagès, F.; Gili, J.-M.; Boero, F. (2006). An introduction to Hydrozoa. Mémoires du Muséum national d'Histoire naturelle, 194. Muséum national d'Histoire naturelle: Paris, France. ISBN 2-85653-580-1. 591 + 1 cd-rom pp. (look up in IMIS) [details]
Usually direct development; entirely pelagic life cycle