Concise hierarchy

(Kingdom) Animalia - (Phylum) Cnidaria - (Class) Hydrozoa

Current position

A-forms ([unranked])

Ref: E.E. Ruppert et al., 2004: fig. 7.74.

Alternative positions

Hydromedusæ (Class)	Ref: E.R. Lankester, 1877: 443.
Hydrozoa (Class) Owen, 1843	Ref: B.C. Das, 2007: 20.

Historical positions

Hydrozoa (Class) Owen, 1843	Ref: B.C. Das, 2007: 20.
A-Forms ([unranked])	Ref: E.E. Ruppert et al., 2004: 167-170, fig. 7.74.
Hydrozoa (Class) Owen, 1843	Ref: A.Yu. Ivantsov & M.A. Fedonkin, 2002: 1123[1223]. [inferred name]
Hydrozoa (Class) Owen, 1843	Ref: R.C. Brusca & G.J. Brusca, 1990
Hydrozoa (Class) Owen, 1843	Ref: D.F. Dunn, 1982: 684.
Hydrozoa (Class) Owen, 1843	Ref: T.I. Storer et al., 1979
Hydrozoa (Class) Owen, 1843	Ref: I. Eibl-Eibesfeldt et al., 1975 (1971): 591.
Hydromedusæ (Class)	Ref: E.R. Lankester, 1877: 443.

Number of Subtaxa

2024	Available in Systema Naturae 2000	15f;39g;17s; †1g;1s
1989-present	Systema Naturae 2000	3so15f[53g]
2016	T.D. O'Hara et al.: R457	175s
2004	E.E. Ruppert et al.	3so
1982	D.F. Dunn: 684	3so15f[53g]