Eucalathis tuberata ( Jeffreys, 1878 )

Eucalathis tuberata ( Jeffreys, 1878) View in CoL

Figures 25 View Figure 25 , 26 View Figure 26

Terebratula tuberata Jeffreys, 1878, p. 401 –402, pl. 22, fig. 2. Terebratulina tuberata – Davidson (1880), p. 13.

Eucalathis tuberata View in CoL – Fischer & OEhlert (1890), p. 72.

Description: Shell moderately ventribiconvex. Outline subtriangular to subpentagonal with rounded front and greatest width anteriorly. Shell usually not much longer than wide. Hinge line nearly straight. Ventral umbo pointed and with high interarea bisected by long V- or U-shaped pedicle opening. Deltidial plates small and triangular. Pedicle collar distinct and strongly raised. Pedicle divided into rootlets. Anterior commissure rectimarginate. Ornamentation of 14–44 costellate ribs, typically strongly beaded by tubercles— especially on ventral valve. Middle dorsal rib stronger or higher than the others and corresponded by an intercosta or two smaller and lower median costellae on ventral valve. Shell matrix endopunctate with very small punctae. Colour greyish to yellowish white. Crenulate valve margin. Strong and very wide hinge teeth not supported by dental plates. Dorsal valve with short but highly raised crura with a short, fragile loop extension usually not preserved. Median septum lacking, but weak median thickening of valve floor often presents in both valves. Shell up to 5 mm long.

Depth range: 549–2995 m depth ( Brunton & Curry 1979; Logan 2007).

Geography: Celtic Sea, Bay of Biscay, Mauritania,? Mediterranean, the Azores, the Mediterranean and south to the Canary Islands ( Brunton & Curry 1979; Logan et al. 2007; Zezina 2014).