Turris ambages Barnard, 1958

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 : 6-7

Turris ambages Barnard, 1958

Plate 2 , figs A–D

Turris ambages Barnard, 1958: 148 , fig. 231; Powell 1964: 337; Barnard 1969: 604, figs 3a, b; Kensley 1973: 202, fig. 798; Kilburn 1983: 556, figs 2 (protoconch), 19–20 (holotype), 21. Type locality (designated Kilburn 1983): off O'Neil [Neill or Cunge] Peak, Zululand, 90 fath. [165 m].

DESCRIPTION: Shell medium-sized, b/l 0.29–0.31, a/l 0.30–0.45, suture relatively shallow, whorls gently convex, last whorl with a basal angle, subsutural cord low, usually shallowly bifid, weakly crenulate or finely pliculate, slightly weaker than sinus cord, sulcus deeply and narrowly channelled; sinus cord on shoulder, bearing a series of low, lunulate crenules or nodules (when fresh each with an oblique basal “tail”); anterior to sinus cord is a prominent, rounded peripheral cord, with sloping sides, and a weaker basal cord. Base of last whorl with wellspaced spiral cords and ridges, upper ones often coarsely nodose, becoming progressively weaker anteriorly, intermediary lirae few or absent. Anal sinus openly U-shaped and relatively shallow.

Yellowish-white, with irregular axial streaks and blotches of brownish-orange, particularly between the crenules.

Protoconch papilliform, of ca 2.5 whorls, the initial one blunt and relatively large; smooth with arcuate axial riblets near termination; diameter ca 1.25 mm.

Attains 50 mm.

DISTRIBUTION: Continental shelf and upper slope of KwaZulu-Natal and southern Mozambique, from Quissico south as far as the Natal /Transkei border, in about 38–165 metres, in sand pockets on low profile sandstone reefs.\

TYPES: Holotype SAMC A8685 .

OTHER MATERIAL EXAMINED (all NMSA, dredged RK et al., unless indicated otherwise): ZULULAND: S.E. of Durnford Point, 95 m, sponge rubble (E8611, E8434) and 100 m, mud and sponge rubble (E8634) . S.E. of Cape Vidal, 110 m, sponge rubble (E4924) . NATAL NORTH COAST: off Tongaat Bluff, 85 m, coarse sand (E9871) . NATAL SOUTH COAST: off Umlaas Canal, 128 m (B6310, B7938), and 135 m (B7939); dredged A. Connell ; N.E.. of Green Point, 75 m, coarse sand and rubble (D3978) , S.E. of Green Point, 100 m, fine sand and rubble (D3981) ; between Green Point and Widenham, 70 m, coarse sand and sponge (D3524) ; off Phumula, southern Natal, 44 m ( NMSA W7420) ; off Scottburgh, 100 m, (B3478: dredged A. Connell) ; off Park Rynie, 100 m, coral rubble (W400) . TRANSKEI: beach drift between Mzamba and Mtentu Rivers, don. J. Stannard (E6014) .

REMARKS: This uncommon south-east African endemic somewhat resembles T. ruthae and T. brevicanalis in its more or less crenulated sinus cord. T. ambages and T. ruthae are compared below. T. brevicanalis has more evenly convex whorls with more numerous, less close-set spiral ridges, of which the peripheral one is relatively weaker than in T. ambages .

Figures

PLATE 2. Turris ambages Barnard, 1958: A, B—S-E of Illovo, southern Natal, 90 m, NMSA D4090, 43.6 x 12.2 mm; C, D—off Phumula, southern Natal, 44 m, NMSA W7420, 51.2 x 16.5 mm.