Benthonellania fayalensis ( Watson, 1886 )

Gofas, Serge, 2007, Rissoidae (Mollusca: Gastropoda) from northeast Atlantic seamounts, Journal of Natural History 41 (13 - 16), pp. 779-885 : 866-867

Benthonellania fayalensis ( Watson, 1886)

( Figure 56 )

Rissoa fayalensis Watson 1886, p 589 , Plate 44 Figure 7 .

Type material

Holotype (sh., 1.60× 0.93 mm) from Challenger sta. 75, in BMNH (1897.2.9.1896).

Type locality

Off Fayal , Azores (38 ° 389N, 28 ° 28.59W, 819–910 m) .

Material examined

Ampère— Victor Hensen VH 97 sta. 97, 5 sh. (1.44×1.00 to 1.90× 1.14 mm); sta. 104, 2 sh. (1.48×0.94 to 1.70× 1.04 mm).

Remarks

The specimens collected on Ampère seamount agree well with the specimens from the type locality and nearby (see Bouchet and Warén 1993, p 680–681), so that this is the first unambiguous report of the species outside the Azores. The reservations expressed previously regarding the assignment to Benthonellania also apply here but, in the absence of data on the living animal the generic placement by Bouchet and Warén (1993) will be respected. The specimens from Ampère seamount and those from the Monaco station cited in Bouchet and Warén were examined under SEM for microsculpture. The former do not show a Porosalvania microsculpture, only very tenuous spiral lines of slit-like pores on some parts of the shells ( Figure 56C ), and the latter are too corroded by acidic glass to conserve any kind of microsculpture.

Figures

Figure 7. (A–D) Alvania microstriata Hoenselaar and Goud, 1998. (A, B) Shells from Seine seamount, DE84 (450–455 m), actual size 1.57 and 1.54 mm; (C) protoconch, same shell as B; (D) microsculpture, same shell as A. (E–H) Alvania seinensis n. sp. (E, F) Holotype (sh.) from Seine seamount, DE72 (165 m), actual size 1.40 mm; (G) protoconch of the holotype; (H) microsculpture. Scale bars: 100 Mm (C, G); 50 Mm (D, H).

Figure 56. Benthonellania fayalensis (Watson, 1886). (A) Shell from Ampère bank, Victor Hensen sta. VH97/97 (800 m), actual size 1.90 mm; (B) protoconch of another shell, same locality; (C) detail of microsculpture, same as (A). Scale bars: 100 Mm (B); 50 Mm (C).