Allogramma formosa (Jeffreys, 1882)

Negri, Mauro Pietro & Corselli, Cesare, 2016, Bathyal Mollusca from the cold-water coral biotope of Santa Maria di Leuca (Apulian margin, southern Italy), Zootaxa 4186 (1), pp. 1-97 : 45

Allogramma formosa (Jeffreys, 1882)

Fig. 10 a–c

Lyonsia formosa Jeffreys, 1882 [a] (p. 930, pl. 70, fig. 1).

Lyonsia (Allogramma) formosa formosa Jeffreys, 1882 — Nordsieck 1969 (p. 157, pl. 22, fig. 90.03). Lyonsia formosa Jeffreys, 1882 — Poppe & Goto 1993 (p. 137, pl. 24, fig. 11); Repetto et al. 2005 (p. 352, mid left fig.). Allogramma formosa (Jeffreys, 1882) — Salas 1996 (p. 71, figs. 101–103); Oliver et al. 2016 (online resource).

Diagnostic characters. Subrectangular shell (when complete); wide obliquely triangular resilial socket; two nodose posterior radial ridges plus some weaker ones on the mid-shell; wavy anterior wrinkles running in dorsoventral direction; sparse rows of minute pustules, raised into short spines over the posterodorsal area. Prodissoconch (badly preserved): shell type?ST-2D; length about 280 µm; outline?roundish; surface probably smooth; P-2 apparently very narrow, rim-like; transition to the nepioconch well marked.

Remarks. A single umbonal fragment of an adult right valve was recovered.

Occurrence. Box-corer sample BC72 (1 specimen). Length: not available.

Distribution and habitat. Allogramma formosa is distributed from the northern Atlantic to the Caribbean basin, the Azores and the Mediterranean (including the Levantine basin), from the lower slope to abyssal depths ( Nordsieck 1969; Poppe & Goto 1993; Galil 2004; Oliver et al. 2016).

Fossil record. None recorded.

Figures

FIGURE 10. a – c: Allogramma formosa (Jeffreys, 1882); RV, sample BC 72, scale bars: 2 mm (a – b), 0.1 mm (c, prodissoconch); d – e: Poromya granulata (Nyst & Westendorp, 1839); LV, sample BC 72, scale bar 1 mm; f – h: Cuspidaria lamellosa (Sars G. O. ex Sars M., 1872); RV (f, h) and LV (g), sample BC 72, scale bars: 1 mm (f – g), 0.1 mm (h, prodissoconch); i – k: Cuspidaria rostrata (Spengler, 1793); RV, samples BC 66 (i – j) and BC 72 (k), scale bars: 5 mm (i – j), 0.1 mm (k, prodissoconch); l – n: Tropidomya abbreviata (Forbes, 1843); LV, sample BC 72, scale bars: 5 mm (m), 2 mm (l, juvenile), 0.1 mm (n, prodissoconch); o – q: Cardiomya costellata (Deshayes, 1835); RV, sample BC 72, scale bars 2 mm (o – p), 0.1 mm (q, prodissoconch).