On some tropical hydroids (Cnidaria: Hydrozoa), with descriptions of four new species Author Galea, Horia R. Hydrozoan Research Laboratory, 405 Chemin Les Gatiers, 83170 Tourves, France. Author Maggioni, Davide Università degli Studi di Milano-Bicocca, Dipartimento di Biotecnologie e Bioscienze, Piazza della Scienza 2, 20126 Milano, Italy. & Marine Research and Higher Education (MaRHE) Center, Università degli Studi di Milano-Bicocca, 12030 Faafu Magoodhoo, Maldives. text Zootaxa 2024 2024-03-20 5428 1 1 57 http://dx.doi.org/10.11646/zootaxa.5428.1.1 journal article 10.11646/zootaxa.5428.1.1 1175-5326 10842930 041905ED-FCED-4ED5-8248-E9AA8D6271E9 Leptothecata : Syntheciidae Synthecium flabellum Hargitt, 1924 , here sequenced for the first time, forms a well-supported monophyletic group (BPP = 0.99, MLBS = 95) with both S. evansi ( Ellis & Solander, 1786 ) and S. tubithecum ( Allman, 1877 ) ( Fig. 26B ).