Caryophyllia (Caryophyllia) diomedeae Marenzeller 1904

New Caledonia and Australia regions, 336-1786 m (Kitahara et al. submitted); off Pacific Panama (Marenzeller, 1904a), 1043 m; Cocos and Galapagos Islands (Cairns, 1991), 245-806 m; New Zealand (Cairns, 1982; 1995), 660-1200 m; northeastern Atlantic from the Mediterranean to the Azores; Bermuda; Cook Islands (Cairns, 1995), 1585 m; Philippines and Indonesia (Cairns & Zibrowius, 1997), 300-885 m; off southeastern and western Australia (Cairns, 1998; 2004), 600-900 m; Vanuatu (Cairns, 1999), 475-799 m; off northern Pacific from 0º to 31ºN (Piñón, 1999; González-Romero et al., 2008), 55-2086 m; off northern Chile (Cairns et al., 2005), 1760 m.

Corallum ceratoid, always attached through a robust pedicel reinforced by concentric layers of stereome (or tectura), which expands into a thin encrusting base. Coralla usually straight or slightly curved near base, but some specimens, especially when fixed to Solenosmilia variabilis, display different shapes. Pedicel up to 11.0 mm in diameter. Largest New Caledonian specimen examined (DW 2066) 25.1 X 21.1 mm in CD, 6.3 mm in PD, and 30.9 mm in height (base broken). Calice slightly elliptical with jagged margins. Theca thick and porcellanous, however expression of costae quite variable. Some specimens have scarce or no indication of costae; some have low and rounded, equal costae separated by shallow grooves; whereas others have C1 and C2 ridged and more prominent than C3 and C4 especially near the calicular edge. Costal granules not common, but when present 3 or 4 (sometimes fused) can be counted across each costa. Corallum white to yellowish-brown, normally darker near base. Septa hexamerally arranged in 4 complete cycles (6:6:12:24 [48 septa]) according to formula: S1-2>S3≥S4. S1-2 very exsert (up to 3.2 mm) especially in larger coralla, with rounded upper edges, and vertical, sinuous axial edges extending about 3/5 distance to columella. Paliferus S3 about 1/2 to 3/4 the exsertness of S1-2, with very sinuous lower axial edges that extend about halfway to columella. Each S3 is separated from their respective P3 by a deep notch (~1mm wide). S4 least exsert septa and equal in width to S3 in smaller coralla, but smaller in larger specimens having only slightly sinuous axial edges. Axial and outer edges of P3 very sinuous and lateral faces granular, forming a distinctive crown around the columella. Septal faces smooth above calicular edge, becoming granular below it. Fossa of moderate depth containing a fascicular columella composed of 3 to 18 twisted elements aligned in the plane of GCD.