Rhizosmilia sagamiensis (Eguchi 1968)

Rhizosmilia sagamiensis (Eguchi, 1968), comb. nov

Coenocyathus sagamiensis Eguchi, 1968:C34, pl. C10: figs. 6, 7.

DESCRIPTION OF SPECIMENS FROM Alb-4944.—One corallum consists of a phaceloid clump of 13 interconnected corallites (Plate 27c), the other corallum is a large solitary specimen (Plate 27d,e). Corallites of colony connected basally by a thin encrusting coenosteum. Corallites ceratoid, the largest measuring 13.3 × 10.3 mm in calicular diameter, 20.1 mm in height, and 5.2 mm in pedicel diameter. Pedicel reinforced by thin raised costae overlain with exothecal dissepiments, this process usually visible on any large specimen. Costae equal in width (0.5–0.6 mm) and finely granular, the C1–3 being slightly ridged near calice. Lower half of theca of largest (solitary) specimen also bears fine transverse rugae. Corallum white, except for brown crescent-shaped bands that parallel the septal edges of S1–2.

Septa generally hexamerally arranged in 4 complete cycles according to the formula: S1>S2>S3>S4, but larger corallites have additional septa and paliform lobes, the largest calice having 68 septa and 16 paliform lobes. S1 highly exsert (up to 3.4 mm), relatively thick, and have straight, vertical inner edges that almost attain the columella. S2 up to 2.5 mm exsert, three-quarters width of S1, and also have straight inner edges. S3 least exsert septa (about 1.1 mm), about three-quarters width of S2, and have slightly sinuous inner edges. A wide (1.1–1.3 mm), lamellar paliform lobe occurs before each S3, separated from its adjacent septum by a deep, narrow notch. S4 less wide but more exsert (1.6–2.0 mm) than S3. Each pair of S4 flanking an S1 or S2 is fused with that septum at the calicular edge to form a 3-septum calicular extension resulting in a highly serrate calicular edge. Fossa of moderate depth, containing the P3 crown of 12–16 lobes and a central fascicular columella consisting of several slender, loosely twisted elements.

azooxanthellate

60-98 m