Belomitra pacifica ( Dall, 1908 )

Kantor, Yuri I., Puillandre, Nicolas, Rivasseau, Audrey & Bouchet, Philippe, 2012, 3496, Zootaxa 3496, pp. 1-64 : 16-17

Belomitra pacifica ( Dall, 1908)

Figures 4C–E, 6

Leucosyrinx ? pacifica Dall 1908: 213 , 270, pl. 12, fig. 3.

Irenosyrinx pacifica ( Dall, 1908) — Dall 1921: 69; Oldroyd 1927: 67.

Morrisonella pacifica ( Dall, 1908) — Bartsch 1945: 23, figs 11–14.

Steiraxis (Irenosyrinx) pacifica ( Dall, 1908) — Clarke 1962: 28.

Aforia pacifica ( Dall, 1908) — Abbott 1974: 265.

Belomitra pacifica ( Dall, 1908) — Bouchet and Warén 1986: 473 (part.), fig. 73 (holotype illustrated).

Type material: Holotype USNM 122590 .

Type locality: Northeastern Pacific , SW off Sitka, Aleutian Is, 55º20’N, 136º20’W, 2860 m. [Albatross sta. 2859] ( Fig. 6) .

Remarks: Based on limited material, Bouchet and Warén (1986) treated B. pacifica as a very broadly distributed and highly variable species, and included in its synonymy Surcula brachytoma Schepman, 1913 and Mangelia paschalis Thiele, 1925 . Based on our newer understanding of variation in species of Belomitra well represented in our material, this synonymy is rejected here, and we presently hypothesize that B. pacifica is a valid species restricted to the North Pacific. The species differs from other Belomitra by having a very weak axial sculpture, present only on upper whorls. The radula was prepared and illustrated by Bartsch (1945), and this was the basis for his establishing the new genus Morrisonella . We re-examined Bartsch's radula preparation and confirmed that it is typical for Belomitra with tricuspid rachidian teeth and typical very long bicuspid lateral teeth.