Notocyathus conicus (Alcock 1902)

Notocyathus conicus (Alcock, 1902)

Citharocyathus conicus Alcock, 1902a:22, pl. 3: figs. 18, 18a.—Faustino, 1927:78, pl. 6: figs. 6, 7.—Wells, 1936:103–104 [designated as type species of genus].—?Yabe and Eguchi, 1941a:414; 1942b:122, pl. 10, figs. 17,18.

Sphenotrochus viola.—Gerth, 1921:393, pl. 57: figs. 10, 11.

Citharocyathus venustus.—Yabe and Eguchi, 1932b:443,444.

Not Citharocyathus conicus.—Yabe and Eguchi, 1941b:212 [= N. venustus].

Notocyathus conicus.—Yabe and Eguchi, 1946:7, figs. 1, 2.—Eguchi, 1965:289, 2 figs.

Not Notocyathus conicus.—Squires, 1958:54–55, pl. 9: figs. 12–14 [= N. euconicus and Peponocyathus sp.]; 1962:147 [= Peponocyathus sp.].

DESCRIPTION.—Corallum conical, constantly increasing in diameter with height; basal angle 40°–70°. Largest specimen examined 7.0×6.9 mm in calicular diameter and 8.1 mm tall (Plate 13a,b, larger syntype). Calice elliptical, the GCD:LCD ranging from 1.01–1.22, with an average of 1.15. Costal size, ornamentation, and arrangement as in N. venustus; however, in larger specimens (e.g., larger syntype) costal granules near the calicular edge are staggered, no longer arranged in unilinear fashion. Width of theca about 0.15 mm.

Septa hexamerally arranged in four cycles according to the formula: S1>S2>S3>S4. S1 exsert, up to 1.3 mm in large specimens, with straight, vertical inner edges extending to the columella. S2 slightly less exsert (e.g., 1.1 mm) and extend about 0.6 distance to columella, where they fuse basally to the fused P3. S3 progressively less exsert (e.g., 1.0 mm) and extend about halfway to columella, where each is bordered by a prominent P3. Because P3 originate from the bottom of a shallow fossa, their upper thecal edges rarely extend above the calicular edge. S4 slightly less exsert (e.g., 0.8 mm, or 0.8 height of S3, independent, and extend about 0.4 distance to columella. Upper edges of all septa rounded. Septal and palar faces covered by prominent elongate to spiniform granules up to 0.18 mm tall on septa (0.22 mm tall on pali), which are often aligned in rows reflecting the underlying trabeculae. As in N. venustus, small P1 and P2 are usually present in small coralla but rarely retain their individual identities in larger coralla. The fusion of the paired P3 is also similar to that of N. venustus.

Fossa usually present as a shallow depression. Columella linear, composed of a loose fusion of 8–12 elements aligned along greater calicular diameter.

Notocyathus conicus (Alcock, 1902)

Citharocyathus conicus Alcock, 1902b:118–119; 1902c:22, pl. 3: figs. 18, 18a.—Yabe and Eguchi, 1941c:212, fig. 4a,b; 1942b:122, pl. 10: figs. 17, 18.

Sphenotrochus viola.—Gerth, 1921:393, pl. 57: figs. 10, 11.

Notocyathus conicus.—Yabe and Eguchi, 1946:7.—Eguchi, 1965:289, 2 figs.—Cairns, 1989a:28, pl. 13: figs. a–i [synonymy].

DESCRIPTION.—Corallum regularly conical, never cylindrical, with a slightly compressed calice having a GCD:LCD range of 1.05–1.22. Largest Japanese specimen examined (TM (KT9015, CB1–2)) 5.85 × 5.39 mm in calicular diameter and 7.60 mm in height. Costal structure and corallum color as in N. venustus.

Septa hexamerally arranged in 4 complete cycles, as in N. venustus, but the relative sizes of septa differ, S1 exsert (about 1.2 mm) and have sinuous vertical inner edges that fuse with the columella deep within fossa. S2 slightly less exsert (about 1.0 mm), two-thirds width of S1, and also have sinuous inner edges that join with the inner P3 fusions. S3 slightly less exsert than S2 (about 0.8 mm) and about two-thirds width of an S2, each S3 separated by a wide notch from a tall, wide (about 0.75 mm) palus. Inner edges of each pair of P3 within a system fused in a V-shaped structure before the S2, as in N. venustus. S4 slightly less exsert than S3 and equal to or slightly less wide than the S3. Fossa quite shallow, containing a papillose colurnella.

azooxanthellate

34-1110 m

slope