heptagonus, Hippocampus Rafinesque [C. S.] 1810:18 [Caratteri di alcuni nuovi generi e nuove specie di animali e piante della Sicilia; ref. 3594] Sicily, Italy, Mediterranean Sea. No types known. Unneeded replacement of Syngnathus hippocampus Linnaeus 1758. Also appeared in Rafinesque 1810:37 [ref. 3595]. Spelled pentagonus by Ginsburg 1937:530 [ref. 1801]. •Synonym of Hippocampus hippocampus (Linnaeus 1758) -- (Wheeler 1973:278 [ref. 7190], Lourie et al. 1999:99 [ref. 23993], Kuiter 2009:18 [ref. 30404], Lourie et al. 2016:27 [ref. 34632], Parenti 2019:102 [ref. 37117]). Replacement Name. Current status: Synonym of Hippocampus hippocampus (Linnaeus 1758). Syngnathidae: Syngnathinae. Habitat: brackish, marine.