<p>Supplementary material (Appendix 1).</p><p>List of additional materials examined for this study. Abbreviations for institutions where this material is deposited: MCZ, Museum of Comparative Zoology, Harvard University; USNM, National Museum of Natural History, Smithsonian Institution. Neospongodes caribaea Deichmann, 1936. MCZ CNID-4068. Syntype, RV Enterprise cruise, off Martinique, West Atlantic, no depth annotated, Captain Cole coll., “nº </p><p>6450”, fragmented colony.</p><p>Siphonogorgia caribaea (Deichmann, 1936). USNM 1025683. North Atlantic Ocean, Gulf of Mexico, Flower Garden Bank, 27º51.45’N 93º49.01’W, 77 m depth, 26 May </p><p>2004, ROV. Det.: S.D. Cairns, 7 Jul 2004. 1 colony.</p><p>Siphonogorgia caribaea (Deichmann, 1936). USNM 52532. North Atlantic Ocean, Caribbean Sea, Barbados, W coast, 50-400 m depth, 2 Aug 1961. Coll.:J. Lewis. Det.: </p><p>F.M. Bayer, 1 fragment.</p><p>Neospongodes agassizii Deichmann, 1936. MCZ CNID-4069. Syntype, USCSS Blake Expeditions, Stn. 45, off Northwest of Dry Tortugas, West Atlantic, 101 fms., collected by Alexander Agassiz, “nº 6454”, 10 fragmented colonies. </p><p>Neospongodes agassizii Deichmann, 1936. MCZ CNID-4383. Syntype, USCSS Blake Expeditions, Stn. 276, off Barbados, West Atlantic, 94 fms., collected by Alexander </p><p>Agassiz, “nº 6464” 5 fragmented colonies. </p><p>Neospongodes agassizii Deichmann, 1936. MCZ CNID-4369. Syntype, USCSS Blake Expeditions, Stn. 132, off Frederikstadt St. Croix, West Atlantic, 117 fms. , collected by Alexander Agassiz, “nº 6474, phot”, 2 fragmented colonies.</p><p>Siphonogorgia agassizii (Deichmann, 1936). USNM 74707. North Atlantic Ocean, Gulf of Mexico, Off Florida, 25º44.50’N 84º21.02’W, 159 m depth, 26 Jul 1981. Det.: </p><p>J.W. Lorry, Dec 1981. 1 fragment.</p><p>Siphonogorgia agassizii (Deichmann, 1936). USNM 74707. North Atlantic Ocean, Gulf of Mexico, Texas, edge off shelf, NW part of Gulf, 28º00.00’N 92º46.30’W, 93-119 m depth, May 1957. Det.: F.M. Bayer, 1960. 1 colony. Siphonogorgia agassizii (Deichmann, 1936). USNM 86975. North Atlantic Ocean , Gulf of Mexico, Florida, W Cape Sable, 25º16.30’N 84º14.46’W, 159 m depth, 10 Feb </p><p>1982. 1 colony.</p><p>Siphonogorgia agassizii (Deichmann, 1936). USNM 1014639. North Atlantic Ocean, Caribbean Sea, Netherland Antilles, Curaçao, South central coast off Piscadera Baai, </p><p>12º06.39’N 68º58.43’W, 101 m depth, 21 May 2000. Det.: S.D. Cairns, Dec 2000. 1 colony.</p><p>Siphonogorgia agassizii (Deichmann, 1936). USNM 82927. North Atlantic Ocean, Gulf of Mexico, Florida, W NW of Dry Tortugas, 25º16.34’N 83º43.40’W, 92 m depth, 5 </p><p>Feb 1988. 1 colony.</p><p>2</p>