1. Species Hormoceras biasolettianum Kützing, 1842 (uncertain, uncertain taxonomic status subjected to verification)
2. Species Hormoceras duriusculum Kützing, 1842 (uncertain, uncertain taxonomic status subjected to verification)
3. Species Hormoceras moniliforme Kützing, 1842 (uncertain, uncertain taxonomic status subjected to verification)
4. Species Hormoceras perversum Kützing, 1842 (uncertain, uncertain taxonomic status subjected to verification)
5. Species Hormoceras purpureum Ardissone, 1861 (uncertain, uncertain taxonomic status subjected to verification)
6. Species Hormoceras transfugum Kützing, 1842 (uncertain, uncertain taxonomic status subjected to verification)
7. Species Hormoceras acrocarpum Kützing, 1863 accepted as Ceramium diaphanum f. acrocarpum (Kützing) Feldmann-Mazoyer, 1941 (synonym)
8. Species Hormoceras capricornu Reinsch, 1875 accepted as Ceramium diaphanum f. capricornu (Reinsch) Foslie, 1893 (synonym)
9. Species Hormoceras catenula Kützing, 1847 accepted as Ceramium deslongchampsii Chauvin ex Duby, 1830
10. Species Hormoceras circinatum Kützing, 1842 accepted as Ceramium circinatum (Kützing) J.Agardh, 1851
11. Species Hormoceras confluens Kützing, 1842 accepted as Ceramium circinatum (Kützing) J.Agardh, 1851 (synonym)
12. Species Hormoceras decurrens Kützing, 1842 accepted as Ceramium circinatum (Kützing) J.Agardh, 1851 (synonym)
13. Species Hormoceras diaphanum (Lightfoot) Kützing, 1842 accepted as Ceramium diaphanum (Lightfoot) Roth, 1806
14. Species Hormoceras flaccidum Harvey ex Kützing, 1862 accepted as Gayliella flaccida (Harvey ex Kützing) T.O.Cho & L.J.McIvor, 2008
15. Species Hormoceras fruticulosum Kützing, 1841 accepted as Ceramium penicillatum Areschoug, 1849
16. Species Hormoceras gracillimum Kützing, 1842 accepted as Ceramium diaphanum (Lightfoot) Roth, 1806
17. Species Hormoceras nodosum Kützing, 1842 accepted as Ceramium diaphanum (Lightfoot) Roth, 1806
18. Species Hormoceras parvulum Zanardini ex Frauenfeld, 1855 accepted as Ceramium parvulum (Zanardini ex Frauenfeld) Grunow, 1867
19. Species Hormoceras polyceras Kützing accepted as Ceramium polyceras (Kützing) Zanardini, 1847 (synonym)
20. Species Hormoceras polygonum Kützing, 1862 accepted as Ceramium diaphanum var. elegans (Roth) Roth, 1806 accepted as Ceramium siliquosum var. elegans (Roth) G.Furnari, 1999 (synonym)
21. Species Hormoceras pygmaeum Kützing, 1847 accepted as Ceramium tenuissimum var. pygmaeum (Kützing) Hauck, 1888 (synonym)
22. Species Hormoceras siliquosum Kützing, 1847 accepted as Ceramium siliquosum (Kützing) Maggs & Hommersand, 1993
23. Species Hormoceras tenerrimum G.Martens, 1866 accepted as Pseudoceramium tenerrimum (G.Martens) Barros-Barreto & Maggs, 2023
24. Species Hormoceras variegatum Kützing, 1849 accepted as Ceramium variegatum (Kützing) Okamura, 1932

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