Bathyal Mollusca from the cold-water coral biotope of Santa Maria di Leuca (Apulian margin, southern Italy) Author Negri, Mauro Pietro Author Corselli, Cesare text Zootaxa 2016 4186 1 1 97 journal article 10.11646/zootaxa.4186.1.1 5b97cddd-5284-4a6b-8693-898864fb4711 1175-5326 165288 029B675F-776C-4CD6-9992-FA05AEADFA7B Adeuomphalus densicostatus (Jeffreys, 1884) Fig. 12 n–p Homalogyra densicostata Jeffreys, 1884 [a] (p. 129, pl. 10, fig. 1). Adeuomphalus ammoniformis G. Seguenza, 1876 — Smriglio et al. 1988 (p. 2, fig. 1); Giannuzzi-Savelli et al. 1994 (p. 106, fig. 349). ? Adeuomphalus ammoniformis Seguenza G., 1876 — Repetto et al. 2005 (p. 90, mid right fig.). Adeuomphalus densicostatus (Jeffreys, 1884) — Kano et al. 2009 (p. 403, figs. 1A–E). Diagnostic characters . Planispiral shell; aperture roundly subrectangular, higher than wide; convex outer lip; two spiral keels on base and apical side; the apical keel weaker, located halfway between suture and periphery; densely spaced, thin and sinuous axial riblets passing over the keels. Protoconch: planispiral; 1.25 whorls; diameter about 150 µm; sculpture of irregularly aggregated, somewhat star-shaped granules; transition to the teleoconch marked by a thin sinuous lip. Remarks . Adeuomphalus ammoniformis Seguenza, 1876 [a] differs in having more quadrangular whorl section and aperture, almost straight riblets, and sharper keels located more peripherally and becoming finely nodulose at the intersections with the riblets. Occurrence . Core BC72 (3 specimens). Maximum diameter: 0.9 mm . Distribution and habitat . Adeuomphalus densicostatus is reported as living in the NE Atlantic, as far South as the Azores , and only as fossil from the Mediterranean; it is a bathyal ( 305–2175 m ) radula-less gastropod, probably living associated with carnivorous sponges of the family Cladorhizidae and feeding on them, often near hydrothermal vents ( Kano et al. 2009 ). Fossil record. Pliocene and Pleistocene of Sardinia and southern Italy ( Di Geronimo & Li Gioi 1980 ; Kano et al. 2009 ).