Physophoridae Eschscholtz 1829

Physonect siphonophores with a vertical nectosome, nectophores budded off on ventral side of stem, with complexly contoured lateral radial canals. Pallial canal with ascending and descending branches. The siphosome is expanded laterally into a spiral sac, on the outer rim of which are placed the cormidial groups, arranged approximately in three spirals, with the palpons forming all or part of the uppermost spiral. Each cormidium is comprised of a gastrozooid, with a tentacle bearing characteristic tentilla, and with or without bracts attached to its peduncle; three large palpons or buds thereof; and a single blastostyle that immediately divides into two branches, one bearing male and the other female gonophores (monoecious).