(Figs. 3 A–B, tables 1−3)
Deltocyathus eccentricus Cairns, 1979: 98, pl. 18, figs. 8−11.—Zibrowius 1980: 86, pl. 40, figs. A–M, pl. 41, figs. A–N.— Cairns & Chapman 2001: 35 (tab. 1).—Brito & Ocaña 2004: 385, pl. 83, figs. A–E.—Kitahara & Cairns 2009: 235 (tab. 1).
Material examined. Galicia Bank: Stn. G 4, 750 m, six specimens, one of them dead; Stn. V 4, 732 m, 71 specimens, three of them dead; Stn. V 5, 877 m, 40 specimens, five of them dead; Stn. V 8, 780 m, two specimens alive and a fragment of a dead specimen.
Description. Corallum free and solitary (H= 0.41−0.51 cm, average= 0.45 cm for n= 30; GCD= 1.0− 1.36 cm, average= 1.22 cm for n= 30, stn. V 4), light, fragile, discoidal to faintly patellate. Base flat to slightly conical with a minute pointed elevation in the epicentre of base. Base costate; costae thin, delicate and finely granular, more developed near calicular margin, arranged according to the formula C 1–2>C 3>C 4. Calices slightly irregular. Septa hexamerally arranged in four complete cycles (S 1 ≥S 2>S 3>S4, 48 septa). S 1 longer than S 2, S 2 than S 3, and S 3 much more than S 4. S 4 poorly developed; S 3 joining with S 2 close to the columella forming a delta, with additional more subtle unions between S 4 and S 3. Septa with axial edges slightly sinuous. Septal faces with small granules that tend to align vertically, occasionally also with fine vertical ridges. Pali in three crowns before S 1 −S 3 (6 P1, 6P2, 12P 3), set apart from septa by a deep notch, sinuous, with small granules. P 1 are the nearest to columella, then P 2, and finally P 3. Fossa shallow, containing a columella below pali level, spongy, with its surface formed by small rods. Corallum white or pinkish.
Remarks. First three cycles are already complete in coralla with GCD= 1.0 cm. In coralla of this size, S 4 are very rudimentary and circumscribed to the calicular margin. Some coralla have supplementary septa (e.g., 52 septa). The junction S 2 −S 3 is distinctive and occurs in the smallest specimens examined. In some specimens, width of C 3 may be similar to C 1 −C 2.
Deltocyathus eccentricus is an amphiatlantic coral known also from the north-western Atlantic (Cairns 1979; Reyes et al. 2009). In the north-eastern Atlantic it is distributed between Azores, the Gorringe Bank, and the Cape Verde Islands (Zibrowius 1980) but rarely recorded. The Galicia Bank population is the northernmost known so far. Deltocyathus eccentricus is a new record for the “West coast of Spain and Portugal (J)” region (see Zibrowius 1980). It was also obtained in the Galicia Bank during the 1987 SEAMOUNT 1 expedition (Zibrowius, com. pers., unpublished). Although there are no Bay of Biscay records, its presence should be expected, particularly in its southern sector. Previous nearest occurrence to the Iberian Peninsula was at 35 º 37.5 ’N – 08º03.2’W (1716−1992 m depth, dead specimen, Zibrowius 1980).