Makiyamaia orthopleura (Kilburn, 1983) Kilburn & Fedosov & Olivera, 2012

Kilburn, Richard N., Fedosov, Alexander E. & Olivera, Baldomero M., 2012, Revision of the genus Turris Batsch, 1789 (Gastropoda: Conoidea: Turridae) with the description of six new species, Zootaxa 3244 (1), pp. 1-58 : 58

Makiyamaia orthopleura (Kilburn, 1983) , new combination

Plate 34 . figs A–C

Turris orthopleura Kilburn, 1983: 560 , figs 3 (protoconch), 24–26. Type loc.: Off Mbashe River, Transkei, South Africa, 100 m., sponges, marine growths, sand.

REDESCRIPTION: Shell pyramidal-fusiform, b/l 0.28-0.30, with very high, acuminately orthoconoid spire (a/l 0.35-0.38), contracted base and narrowly elliptical aperture; rostrum tapering, terminally rounded, not indented, fasciole present but only weakly swollen; false umbilicus absent. Inner lip with a smooth, glossy callus, its edge adnate; outer lip thin, anal sinus shallowly U-shaped, [edge of lip damaged anteriorly].

Sculpture: Early whorls with 5–6 narrow, more or less equal, spiral ridges, on 4th -5th whorls becoming more widely spaced, sometimes with additional ridges interpolated. By the 8th whorl a shallow concavity has developed at or slightly above midwhorl; by the last (12th) whorl subsutural region has become tumid and bears about 5–6 fine spiral threads; lower half-whorl with 3 whitish spiral threads, with denser, finer threads interpolated. Base of last whorl with numerous (approximately 37) very fine and closely-set spiral threads. Collabral striae (“growth lines”) coarse, rendering the finer spirals slightly granulose, becoming very coarse on later part of last whorl.

Tinged with pale brown, with slightly darker brown, sinuous, collabral strigations; lower part of each whorl with 1– 2, fine, whitish, spiral threads; base of last whorl reddish-brown, darkest anteriorly, apex also darker; interior of aperture and columella callus tinged with pinkish or violaceous.

Protoconch slightly swollen, of ca 2.0 whorls, first whorl bulbous, initially tilted, somewhat naticoid, of about 1 whorl, 2nd whorl with opisthocline axial ribs, termination concave (not sinusigerous); breadth 1.30–1.50 mm. Dimensions of adult specimens: 51.0 x 15.2 mm, 50.3 x 14.2 mm.

DISTRIBUTION: Apparently endemic to outer shelf and upper slope of S. E. Africa, from southern Natal (Park Rynie) to Transkei (off Qolora), 84–130 m, on sand and sponge.

ADDITIONAL RECORDS: off Mbotyi, Transkei (pl. 33, figs B–C), in 90 m, coral rubble, dredged W. Immelmann ( NMSA W7421) ,

TYPES: Holotype NMSA W2834 , 7 immature paratypes in NMSA .

REMARKS: The protoconch is indicative of a limited range endemic.

Figures

PLATE 34. Makiyamaia orthopleura (Kilburn, 1983): A—Holotype of Turris orthopleura, off Mbashe River, Transkei, 100 m, South Africa, NMSA 2834, 29.0 x 10.0 mm; B, C—off Mbotyi, Transkei, South Africa, 90 m, NMSA W2834, 50.8 x 15.0 mm.