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 Montacuta substriata ( Montagu, 1808 ) Fig. 8 a–c Ligula substriata Montagu, 1808 (p. 25). Montacuta substriata Montagu—Jeffreys 1881 (p. 698); Hidalgo 1917 (p. 450). Montacuta substriata (Montagu) — Deroux 1961 (p. 107, fig. 4 M. s.); Tebble 1966 (p. 89, text-figs. 42a–c). Montacuta substriata (Montagu, 1809) — Nordsieck 1969 (p. 93, pl. 14, fig. 52.40). Montacuta substriata ( Montagu, 1808 ) — Poppe & Goto 1993 (p. 87, pl. 14, fig. 13); Repetto et al. 2005 (p. 315, mid right fig.); Oliver et al . 2016 (online resource). Diagnostic characters . Oval outline; very long anterior side; hinge of the right valve with an obliquely elongate anterior cardinal tooth; 9–10 weak radial ridges in the middle of the shell. Prodissoconch: shell type ST-2A; length about 210 µm (P-1 about 120 µm); slightly oval outline, somewhat more elongated in posteroventral direction; convex profile; P-1 roughly D-shaped, flattened, elevated with respect to P-2; P-1 surface weakly striated around the cicatrix; P-2 with dense fine commarginal growth welts; transition to the nepioconch well marked (no lip). Remarks . The elevated P-1 appears to be rather unusual, as well as the dense growth markings on P-2; consequently, the P-1/P-2 transition could also be interpreted as prodissoconch/nepioconch transition. We consider the concentrically sculptured shell as P-2 because of the clear demarcation with the adult shell and the completely different scupltural features of this latter. Occurrence . Box-corer sample BC72 (1 specimen). Length: 2 mm . Distribution and habitat . Montacuta substriata is distributed from Iceland to the Mediterranean, at infralittoral depths and down to about 600 m , being a commensal organism living attached to the anal spines of the heart urchins Spatangus purpureus and Echinocardium flavescens ( Nordsieck 1969 ; Poppe & Goto 1993 ; Oliver et al. 2016 ). Fossil record. Plio-Pleistocene of Norway and Italy ( Monterosato 1872 ; Monegatti & Raffi 2001 ).