Conotrochus funicolumna (Alcock 1902)

Conotrochus funicolumna (Alcock, 1902)

Ceratotrochus (Conotrochus) funicolumna Alcock, 1902a:93; 1902c: 11–12, pl. 1: figs. 6, 6a.—Faustino, 1927:66, pl. 9: figs. 7, 8.—Yabe and Eguchi, 1942b:117, pl. 9: fig. 11.—Eguchi, 1968:C38–39.—Zou, 1988:77, pl. 5: figs. 1. la.

Conotrochus funicolumna.—Cairns, 1984:14, pl. 2: figs. I.J. Conotrochus sp. cf. C. funicolumna.—Cairns and Parker, 1992:22, pl. 6: figs. c.f.

Ceratotrochus hiugaensis Yabe and Eguchi, 1942b: 117, 146, pl. 9: fig. 10a,b.—Eguchi, 1965:288. 2 figs.

Ceratotrochus (Conotrochus) parahispidus Yabe and Eguchi, 1942b: 118, 147–148, pl. 9: fig. 12a,b.—Eguchi, 1965:288. 2 figs; 1968:C39.—Eguchi and Miyawaki, 1975:57.

DESCRIPTION.—Corallum trochoid to ceratoid, slightly curved, and usually free, but sometimes attached through a slender pedicel or attached along a small section of lower theca. One illustrated specimen (Plate 25i,l) is 13.6 × 13.0 mm in calicular diameter and 17.8 mm in height. Alcock's (1902c) figured syntype is 11.9 × 11.7 mm in calicular diameter and 13.1 mm in height. Theca thick but invariably worn, revealing coarsely granular costae covered by a thin epitheca. Upper theca projects 0.5–0.7 mm above upper, outer septal edges as a continuous rim, which is characteristic of the genus. Corallum white.

Septa hexamerally arranged in 4 complete cycles: S1–2>S3>S4. S1–2 only slightly exsert above encircling thecal rim and have straight, vertical inner edges that join the columella only deep within fossa. S3 about 80% width of S1–2 and also have straight inner edges that fuse with the columella only lower in fossa. S4 one-quarter to one-third width of S3 and have entire inner edges that do not attain the columella. All septal faces bear very low granules, giving the impression of smooth septal faces. Fossa shallow. Columella prominent, composed of an elliptical mass of slightly swirled lamellar elements, the uppermost 5 mm remaining free of septal fusion.