Truncatoflabellum carinatum Cairns 1989

Truncatoflabellum carinatum

Flabellum rubrum.—Faustino, 1927:53 [in part: ALB-5311].—Yabe and Eguchi, 1942a:96–98, [in part: pl. 8; figs. 6–12, 20]; 1942b:131–132 [in part].—Umbgrove, 1950:641 [in part: pl. 81: figs. 5, 6].

?Flabellum variabile forma alta Gerth, 1921:40, pl 57: fig. 16.

DESCRIPTION.—Angle of acute thecal edges 35°–50°; inclination of slightly convex thecal faces 18°-26°, anthocyathus quite compressed near base. Largest anthocyathus (holotype) examined 23.4 × 14.6 mm in calicular diameter and 26.8 mm tall, with a basal scar of 5.0 × 2.0 mm. Edges of lower half of corallum carinate, projecting as low, thin, continuous ridges up to 2 mm tall. Four pairs of thecal edge spines present on better-preserved specimens. Basal scar small, 4.5–5.2 × 1.72.0 mm in diameter. Anthocaulus unknown. Theca light reddish brown and free of encrustation. Theca smooth, marked by fine white longitudinal striae that delimit costae, which are equal in width, about 0.3 mm wide. Calice elliptical: GCD: LCD = 1.6–1.9.

Septa hexamerally arranged in five cycles according to the formula: S1–3>S4>S5. Aspects of septal shape, relative septal exsertness, granulation, and presence of a septal notch unknown due to poor preservation of all specimens available. Inner edges of S1–3 vertical, thickened, and quite sinuous. Lower, inner edges of S1–3 form a loosely tangled columella deep in fossa.

Truncatoflabellum carinatum Cairns, 1989

Flabellum rubrum.—Faustino, 1927:53 [in part: Alb-5311].—Yabe and Eguchi, 1942a:96–98 [in part: Soyo Maru 222, pl. 8: figs. 6–12, 20]; 1942b:131–132 [in part].

Flabellum rubrum stokesii.—Yabe and Eguchi, 1942a:98–99 [in part: Soyo Maru-295, 304].

Truncatoflabellum carinatum Cairns, 1989a:73–74, pl. 38: figs. b–e.

DESCRIPTION.—The following description is based on one well-preserved specimen from off the Pescadores Islands (ex CAS 74990). Corallum (anthocyathus) compressed, the evenly convex thecal faces meeting in an acute angle at thecal edges. Three or 4 pairs of low (about 1.0 mm in height) discontinuous crests or spurs (not spines) occur along each thecal edge. Corallum 26.7 × 14.4 mm in calicular diameter, 22.5 mm in height, and 3.7 × 6.2 mm in basal scar diameter, making it the largest specimen known. Edge angle 57°; inclination of lateral faces, 33°. Theca white and somewhat rough, displaying chevron-shaped epithecal growth lines that peak at the 24 S1–3.

Septa hexamerally arranged in 5 complete cycles, with 4 additional pairs of S6 in quarter-systems adjacent to the 2 principal septa (104 septa). S1–3 have vertical, sinuous inner edges that attain the columella. Septal faces distinctively lined with 15–18 low ridges oriented perpendicular to the septal edge, each ridge bearing a series of low, triangular granules. Ridges alternate in position with those on opposite face of same septum. S4 about two-thirds width of an S1–3 and have poorly formed, finely dentate inner edges that do not fuse with the columella. S5 quite small, only about one-quarter width of an S4. The 4 pairs of S6 are rudimentary. Fossa deep and elongate, containing a well-formed, elongate columella about 2.1 mm wide.

azooxanthellate

30-274 m