Trivellona pulchra, Fehse & Grego, 2012

Trivellona pulchra View in CoL spec. nov.

Figs 2-6 View Figs 2- 6

Trivellona sp. indet. C – Fehse & Grego 2004, 2009: pl. 15, fig. 61.

Types. Empty shells were dredged at Aliguay Island , near Dipolog, Mindanao, Philippines in depths of 150 m in rubble . Holotype: ZSM 20100398 View Materials .– Paratypes: No. 1: DFB 7850-1 ; No. 2: DFB 7850-2 ; No. 3: DFB 7850-3 ; No. 4: DFB 7850-4 ; No. 5: DFB 7850-5 ; No. 6: MBI T0189 ; No. 7: JGS T0190 ; MBI T0199 . All material comprises empty shells from type locality that were obtained from different reliable sources.

Description

Shell medium sized (see Table 1 View Table 1 ), lightweight, somewhat fragile, globose. Spire slightly elevated, covered with terminal ribs. Body whorl somewhat pyriform, globose, rounded, approximately 90 % of total shell height; anterior terminal produced, tip indented; posterior terminal slightly so. Anal canal indented. Dorsum evenly rounded, highly elevated, completely covered by very fine, close-set ribs with a slight mid-dorsal depression; occasionally ribs bisected mid-dorsally. Ventrum convex, with terminal collars straight. Aperture relatively narrow, curved especially towards the canals. Labrum narrow, straight at its mid-portion, curved anteriorly and posteriorly, posteriorly projecting, roundly keeled on ventrum, anteriorly flattened, bearing on its inner margin fine denticles. Outer labral margin angularly callused with a sharp ridge on shoulder and with posterior-most labral denticles projected. Siphonal and anal canals following shell profile; bordered adapically by a weak and abapically by a large ventral side wall. Columella narrow, straight, tapering steeply inwards, without a carinal ridge. Parietal lip roundly callused, slightly projected, anteriorly ridged, bearing fine ribs, which become even finer, slightly obscured onto the columella. Fossula short, broadly concave, not clearly delimited from the rest of the columella. Inner fossular edge slightly protruding.

Shell colour white with terminal collars pale red-brown.

No information available on soft parts and radula.

Variation. The available shells are very uniform in their appearance ( Table 1 View Table 1 ). Their inflation varies a bit. The inner fossular margin is more or less protruded. The number of dorsal ribs varies between 36 and 44, of labral denticles between 25 and 29, of parietal ribs between 23 and 27 and of terminal ribs that cover the spire between 5 and 7.

Etymology. From the Latin adjective ‘pulcher’, meaning beautiful.

Distribution. Only known from the type locality ( Fig. 1 View Fig ).