Concise hierarchy

(Kingdom) Animalia - (Phylum) Cnidaria - (Class) Hydrozoa - (Order) Anthoathecatae - (Family) Hydridae

Original position

Zoophyta (Order) Linnaeus, 1758

Subsequent positions

Hydridae (Family) Dana, 1846

Original entries

Hydra berberina Linnaeus, 1758
Hydra campanulata Linnaeus, 1758
Hydra convallaria Linnaeus, 1758
Hydra crataegaria Linnaeus, 1758
Hydra digitalis Linnaeus, 1758
Hydra opercularia Linnaeus, 1758
Hydra polypus Linnaeus, 1758
Hydra pyraria Linnaeus, 1758
Hydra socialis Linnaeus, 1758
Hydra stentoria Linnaeus, 1758
Hydra umbellaria Linnaeus, 1758

Current position

Hydridae (Family) Dana, 1846

Ref: B.C. Das, 2007: 20.

Alternative positions

Athecata (Order)	Ref: A.C. Campbell, 1994 (1976)
Hydrina (Order)	Ref: I. Eibl-Eibesfeldt et al., 1975 (1971): 591. [inferred name]
Zoophyta (Order) Linnaeus, 1758	Ref: [von] Linné, C., 1767: 1320.

Historical positions

Hydridae (Family) Dana, 1846	Ref: B.C. Das, 2007: 20.
Medusozoa (Subphylum) Petersen, 1979	Ref: T. Cavalier-Smith, 1998: table 4 (p. 235). [rough position]
Cnidaria (Phylum) Hatschek, 1888	Ref: C. Nielsen, 1995
Anthomedusae (Suborder)	Ref: R.C. Brusca & G.J. Brusca, 1990
Hydrozoa (Class) Owen, 1843	Ref: R.S. Boardman et al., 1987
Cnidaria (Phylum) Hatschek, 1888	Ref: L. Margulis & K.V. Schwartz, 1982: 170. [rough position]
Hydridae (Family) Dana, 1846	Ref: D.F. Dunn, 1982: 677.
Hydrina (Order)	Ref: I. Eibl-Eibesfeldt et al., 1975 (1971): 591. [inferred name]
Hydriformes (Order)	Ref: E.R. Lankester, 1877: 443. [rough position]
Zoophyta (Order) Linnaeus, 1758	Ref: C. a Linné, 1767: 1074, 1320.
Zoophyta (Order) Linnaeus, 1758	Ref: C. Linnaeus, 1758: 646, 816.

Number of Subtaxa

2025	Available in Systema Naturae 2000	11s
1989-present	Systema Naturae 2000	[11s]
1758	C. Linnaeus	[11s]