Turris bipartita, 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 : 10-12

Turris bipartita nom. nov.

Plate 5 , figs A–J

Pleurotoma variegata Kiener, 1839 (non Philippi, 1836): 14, pl. 9, fig. 1. Type loc.: l’Océan Indien ”.

Turris variegata ; Gravely 1942: 73; Pinn 1990: 111, fig. 204; Kilburn 2002: 12.

Turris crispa variegata ; Powell 1964: 332, pl. 254, fig. 2.

? Pleurotoma indica Deshayes, 1833 (non Turris indica Röding, 1798 ): 421, pl. 2, figs 9–10; Kiener 1839: 16, pl. 11, fig. 1. Type loc.: “ Ceylan ” [ Sri Lanka].

DESCRIPTION: Shell fusiform, b/l 0.26–0.33, a/l 0.41–0.45, siphonal canal long and narrow to fairly broad and moderately short, recurved, adults with a fasciole and false umbilicus. Suture shallow; outer lip moderately convex in side view, its edge weakly crenate, anal sinus rather shallow, linear to linguiform.

Subsutural cord low and somewhat sloping, bearing 2–3 thin, angular ridges, their intervals pliculated by collabral threads. Sulcus relatively shallow and sloping, containing 2–3 spiral threads. Sinus cord flat-topped to shallowly bifid. Peripheral cord typically angular, projecting slightly to strongly beyond sinus cord. Base of spire whorls with 2–3 weak, angular main cords and 1–2 weaker spiral threads filling each interval. Base of last whorl with 17–24 low, angular spiral lirae with rather numerous intermediary threads, cancellated by collabral threads. Collabral threads dense, mainly in interstices.

Protoconch small and paucispiral. evidently of about 2.0 whorls, the last half-whorl axially ribbed, with the beginnings of a subsutural cord, breadth ca 0.90 mm.

Cream-colour with brownish flames or small blotches on subsutural cord and around upper part of base of last whorl (often forming a strong band), elsewhere sometimes with irregular oblique axial brown bands, which form spots on the ridges; occasionally uniform light brown or white with faint markings.

Maximum length 85.0 mm.

DISTRIBUTION: South-eastern India (Chennai southwards) and probably Sri Lanka, sand and marine grass in 2– 16 m.

TYPES: P. variegata : syntype in MNHN . P. indica : syntype in MNHN (although labelled “holotype”, Deshayes implied that he had a number of specimens) .

PUBLISHED RECORDS: Chennai (Madras) ( Powell (1964), Gravely (1942)); Tuticorin, 9 fath. [16 m] ( Powell 1964); Pondicherry ( Pinn 1990).

MATERIAL EXAMINED: INDIA: off Koswari Is., Tuticorin area, 2–3 m ( NMSA L5412: RK) ; Chennai (Madras) (B0 colln: L. Strange, also NMSA J4911: T. Honker) .

REMARKS: Little material of this species has been examined. Typical examples (Pl. 5, figs A–F) are available from Chennai (Madras), and one from Pondicherry is illustrated by Pinn (1990). The form common in the Tuticorin area of the Gulf of Mannar (Pl.5, figs I–J) differs somewhat in its proportions, being broader with a shorter, wider siphonal canal (often forming a strong fasciole in adults) and its spiral sculpture is coarser; this material agrees better with the MNHN specimen (Pl. 5, figs G–H) labelled as the holotype of P. i n d i c a. The latter is for the present regarded as a species dubium.

Powell’s statement that T. variegata is “probably restricted to the west coast of India ” is a laps. cal.: The species is reliably reported only from the east coast.

ETYMOLOGY: bi (two) + partita (divided), alluding to the two strongly variegated zones on the last whorl.

Figures

PLATE 5. Turris bipartita nom. nov.: A, B—Syntype of Pleurotoma variegata Kiener, 1839 (non Philippi, 1836), Indian Ocean, MNHN, 84.6 x 22.1 mm; C—Madras, India, BO colln, 64.1 x 18.5 mm; D, E—Madras, India, BO colln, 74.0 x 20.5 mm; F—Madras, India, BO colln, 68.0 x 20.2 mm; G, H—Holotype of Pleurotoma indica Deshayes, 1833 (non Turris indica Röding, 1798): MNHN, "Ceylan" (Sri Lanka), MNHN, 76.8 x 23.3 mm; I, J—Off Koswari Is., Tuticorin area, SE India, 2–3 m, NMSA L5412, RK, 66.3 x 18.9 mm.