planifrons, Hippocampus Peters [W. (C. H.)] 1877:851 [Monatsberichte der Königlichen Preussischen Akademie der Wissenschaften zu Berlin 1876; ref. 3454] "Naturalists Channel", northwestern Australia, depth 10 fathoms. Holotype (unique): ZMB 9387. •Questionably a synonym of Hippocampus trimaculatus Leach 1814 -- (Lourie et al. 1999:171 [ref. 23993]). •Valid as Hippocampus planifrons Peters 1877 -- (Paxton et al. 1989:422 [ref. 12442], Larson & Williams 1997:352 [ref. 23967], Francis 1993:159 [ref. 25479], Paulus 1999:2269 [ref. 24794], Johnson 1999:726 [ref. 25471], Kuiter 2001:310 [ref. 25900], Hutchins 2001:27 [ref. 25847], Paxton et al. 2006:827 [ref. 29073], Kuiter 2009:126 [ref. 30404], Lourie 2016:103 [ref. 34505], Lourie et al. 2016:35 [ref. 34632], Short et al. 2019:117 [ref. 36532]). Current status: Valid as Hippocampus planifrons Peters 1877. Syngnathidae: Syngnathinae. Distribution: Western Australia, Australia: Shark Bay to Exmouth. Habitat: marine.