Fig. 13 m–o
Lacuna tenella Jeffreys, 1869 (p. 204, pl. 101, fig. 7).
Cithna tenella Jeffreys—Jeffreys 1883 [b] (p. 110); Hidalgo 1917 (p. 244).
Cithna tenella (Jeffreys) — Nordsieck 1968 (p. 32, pl. 5, fig. 16.30); Di Geronimo & Panetta 1973 (p. 74, pl. 1, fig. 2); Di Geronimo 1974 (p. 149, pl. 2, figs. 1,4; pl. 3, figs. 7–8); Di Geronimo & Bellagamba 1985 (pl. 3, figs. 1–2).
Cithna tenella (Jeffreys, 1869) — Grecchi 1984 (p. 21, pl. 2, figs. 3, 6).
Benthonella tenella (Jeffreys) — Ponder 1984 (p. 63, figs. 39C–D, 40, 119A–E); Di Geronimo et al. 1997 (pl. 2, fig. 4); Di Geronimo et al. 2001 (pl. 1, fig. 13).
Benthonella tenella (Jeffreys, 1869) — Bouchet & Warén 1993 (p. 697, figs. 1636–1650); Repetto et al. 2005 (p. 120, bottom left fig.); Beck et al. 2006 (p. 63, top fig.).
Benthonella tenella (Jeffreys, 1867) — Warén 1996 (p. 215, figs. 7B, 12C).
Diagnostic characters. Turbiniform shell; moderately high spire; drop-shaped aperture; small umbilical chink; smooth surface except for opisthocyrt growth lines. Protoconch: low conical; 3.25 whorls; diameter about 590 µm (protoconch I: 120 µm); height about 220 µm; first 1.1 whorls (protoconch I) with spiral lines and microgranules in between; subsequent whorls (protoconch II) with two spiral threads (one suprasutural, one about halfway between sutures) and adapical bar-like pustules; transition to the teleoconch marked by an opisthocyrt lip.
Occurrence. Box-corer samples BC04 (7 specimens), BC05 (5), BC11 (2), BC72 (8); cores BC04 (2), BC05 (50), BC21 (16), BC51 (13), BC72 (2). Maximum height: 2.5 mm.
Distribution and habitat. Benthonella tenella ranges from the northern Atlantic (as far north as Iceland and NE American coasts) to the Caribbean, the Azores, the Canaries and the whole Mediterranean basin, being also patchily present in the southern Atlantic; it is normally found in the 500–4000 m depth interval on muddy and silty bottoms (Nordsieck 1968; Di Geronimo & Panetta 1973; Bouchet & Warén 1993; Warén 1996; Sneli 2005). It has been regarded to represent an exclusive characteristic element of either the VP (bathyal mud) or CB (deep-sea white corals) biocoenoses (Di Geronimo & Bellagamba 1985). In the Santa Maria di Leuca CWC biotope, it was found on soft substrates around coral colonies (Mastrototaro et al. 2010).
Fossil record. Pliocene and Pleistocene of Italy (Di Geronimo & Bellagamba 1985; Di Geronimo et al. 1997; Tabanelli 2008).