Azooxanthellate Scleractinia (Cnidaria, Anthozoa) from South Africa Author Filander, Zoleka N. https://orcid.org/0000-0002-6905-4440 Biodiversity and Coastal Research, Oceans and Coasts, Department of Environment, Forestry, and Fisheries, Cape Town, South Africa & Zoology Department, Nelson Mandela University, Port Elizabeth, South Africa zfilander@gmail.com Author Kitahara, Marcelo V. Universidade Federal de Sao Paulo, Departamento de Ciencias do Mar, Santos, Brazil & Centro de Biologia Marinha, Universidade de Sao Paulo, Sao Sebastiao, Brazil Author Cairns, Stephen D. Department of Invertebrate Zoology, Smithsonian Institution, Washington DC, USA Author Sink, Kerry J. South African National Biodiversity Institute, Cape Town, South Africa & Institute for Coastal and Marine Research, Nelson Mandela University, Port Elizabeth, South Africa Author Lombard, Amanda T. Institute for Coastal and Marine Research, Nelson Mandela University, Port Elizabeth, South Africa text ZooKeys 2021 2021-10-28 1066 1 198 http://dx.doi.org/10.3897/zookeys.1066.69697 journal article http://dx.doi.org/10.3897/zookeys.1066.69697 1313-2970-1066-1 133CE040A5AF44F1BC9A558C2F06A8AA BD84F4C3157550C9B64120B2BE53F01A Balanophyllia (Balanophyllia) diademata van der Horst, 1927 Fig. 7O, P Balanophyllia diademata van der Horst, 1927: 4-5, pl. 2, figs 8, 9. - Cairns and Keller 1993 : 220. Balanophyllia (Balanophyllia) diademata . - Cairns 2001 : 16. Type locality. Off the north-west of Port Dunford; 165 m ( van der Horst 1927 ). Type material. Unknown. Material examined. DEFF_FHolon-INV 1 ( 1 specimen ): Eastern margin, off Sodwana ; 120 m . SAMC_A073016 ( 1 specimen ): Eastern margin, 31 km from Richards Bay / 46 km Mlalazi Estuary , 29°00'54.00"S , 32°15'35.99"E ; 500 m . Description. Corallum ceratoid, straight to slightly curved, and attached by a robust pedicel (PD:GCD = 0.5) that expands into a thin encrusting base. Calice slightly elliptical (GCD:LCD = 1.4-1.5). Largest examined specimen (SAMC_A073016) 12.7 x 8.5 mm in CD, 6 mm in PD, and 24.8 mm in H. Examined specimens lack epitheca. Costae corresponding to septa size (with C3-5 being narrow), porous, densely covered with granules, and separated by narrow and deep intercostal furrows. Septa hexamerally arranged in five incomplete cycles according to the formula: S1> S2> S3> S5> S4 (≤ 82 septa). S1-2 most exsert, independent, and reach columella with straight and laciniate axial margins. Higher cycle septa (S3-5) progressively less exsert. S3 dimorphic in size: those in half-systems with S5 ~ 1/2 size of S2; but 1/4 the size of S2 in half-systems without S5. S3 have slightly dentate to laciniate axial margins. S4 also dimorphic in size: 1/4 width of S3 in half-systems with S5; but double the width of S3 in half-systems that lack S5. A pair of S4 merges in front of flanked S3 before joining columella as one septum. S4 axial margins slightly more dentate than S3. S5 (when present) has double the width of S4, fusing towards flanked S4 before extending to columella as one septum. S5 bear the most dentate axial margins. All septal faces covered with granules. Septa appear slightly crowded. Fossa of moderate depth, containing a slender, low-profile, and elongated spongy columella. Distribution. Regional: Eastern margin of South Africa, off Richards Bay extending towards Sodwana; 120-500 m. Elsewhere: Only known from South Africa. Remarks. The examined material complements van der Horst's (1927) description of Balanophyllia (B.) diademata , particularly in the irregularity of the number of septal cycles per half-system. However, the examined specimens lack epitheca, whilst van der Horst's (1927) figured specimen show epitheca reaching ≤ 2.0 mm from calicular margin.