Hydrozoa source details
Campbell, R.D., 1989. Taxonomy of the European Hydra (Cnidaria: Hydrozoa): a re-examination of its history with emphasis on the species H. vulgaris Pallas, H. attenuata Pallas and H. circumcincta Schulze. Zool. Jl Linn. Soc. 95 3: 219-244.
The name Hydra attenuata Pallas is currently applied to the wrong animal. The common brown polyp, which is widely called H. attenuata was described by Pallas (1766) as Hydra vulgaris. The name H. attenuata Pallas originally referred to an uncommon pale polyp, currently known as H. circumcincta Schulze. The history of this confusion is analysed here. The taxonomy of hydra was in disarray during the 18th and 19th centuries, and was clarified in 1917 with the monograph of Schulze. But Schulze misapplied the name for the common hydra, H. vulgaris, to an unusual form and thus was led to assign the name of a rare hydra, H. attenuata, to the common type. Schulze redescribed the rare, pale hydra that Pallas had named H. attenuata as H. circumcincta. The correct name of the common European brown, stalkless hydra is thus H. vulgaris Pallas, 1766. The name H. attenuata has priority for the uncommon pale hydra, but because of disuse of this application of the name, the pale hydra should be recognized by the current, generally accepted binominal H. circumcincta Schulze, 1914. figs. 1-5. (03.iii.1989). AGGIORNAMENTO FAUNA ITALIANA