This study reviews all European hydroids belonging to the filiferan families Bythotiaridae, Proboscidactylidae,Magapiidae, Ptilocodiidae, Eucodoniidae, Russelliidae, Niobiidae, Protiaridae, and Trichydridae. Protiara tetranema (Péron & Lesueur, 1810) isconsidered as an unrecognizable species. The gonozooids of Halitiara formosa and Trichydra pudica are described, both have reduced blastostyles in a gonotheca-like casing.
Cnidaria - marine - Hydrozoa - revision - taxonomy