The order Zoantharia Rafinesque, 1815 (Cnidaria, Anthozoa: Hexacorallia): supraspecific classification and nomenclature Author Low, Martyn E. Y. Lee Kong Chian Museum of Natural History, National University of Singapore, 2 Conservatory Drive, Singapore 117377, Republic of Singapore & former address: Department of Marine and Environmental Sciences, Graduate School of Engineering and Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903 - 0213, Japan Author Sinniger, Frederic Tropical Biosphere Research Center, University of the Ryukyus, 3422 Sesoko, Motobu, Okinawa 905 - 0227, Japan Author Reimer, James Davis Molecular Invertebrate Systematics and Ecology (MISE) Laboratory, Department of Marine and Environmental Sciences, Graduate School of Engineering and Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903 - 0213, Japan; and Tropical Biosphere Research Center, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903 - 0213, Japan jreimer@sci.u-ryukyu.ac.jp text ZooKeys 2016 2016-12-14 641 1 80 http://dx.doi.org/10.3897/zookeys.641.10346 journal article http://dx.doi.org/10.3897/zookeys.641.10346 1313-2970-641-1 903D6413C8024864A662D71C50740E2D BB707A65FFDFFFFBFFFE8B61FFD5FF91 579464 Terrazoanthus Reimer & Fujii, 2010 Terrazoanthus Reimer & Fujii, 2010: 20. Type species. Terrazoanthus onoi Reimer & Fujii, 2010, by original designation. Gender. Masculine. Diagnosis. This genus is characterised by being a member of the Hydrozoanthidae that is found on rocky substrates (as opposed to being obligate symbionts with hydrozoans). Some species in this genus are also brightly coloured (see Reimer and Fujii 2010 : 20). Remarks . Sphincter muscle transitional, with distal half mesogleal and proximal half endodermal, with encrustations to endodermal surface of mesoglea ( Swain and Swain 2014 ) (=meso-endo transitional [ Swain et al. 2015 ]), although Terrazoanthus minutus (Duerden, 1898) has a simplified mesogleal sphincter muscle ( Swain et al. 2015 ). Described species currently referable to the genus Terrazoanthus are mainly from the East Pacific, with Terrazoanthus minutus from the Caribbean, and it is likely that several more undescribed species exist in the Atlantic (see Reimer et al. 2010a , 2012a ) and in the Central Indo-Pacific region ( Reimer et al. 2014b ). The diagnosis of Terrazoanthus is in need of revision with the placement of Terrazoanthus patagonichus (Carlgren, 1898) into this genus by Swain et al. (2015) as this species is associated with hydroids ( McMurrich 1904 ).