Figures 16 I–K urn:lsid:zoobank.org:act: 43C32B8B-2255-4ED0-B805-F6A619C56D04
Type locality: W end of Akutan Island, Fox Ids., Aleutian Is., Alaska (54°10.5 N, 166°07.6 W), 411 m (NMFS 94- 199701 - 29).
Type material: Holotype: LACM 3585, 160 mm. (leg. 23 May, 1997, trawled R/ V Vesteraalen); Paratypes: Pt 1, LACM 3631, 85.0 mm. Kanaga Pass, W of Kanaga Island, Andreanof Ids. (51°45.8 N, 177°21.3 W), 148 m (leg. Rae Baxter, 20 Aug. 1986); Pt 2, SBMNH 169008, 119.5 mm. SSE of Yunaska Island, Islands of four Mountains (52°31.33 N, 170°39.41 W), 130 m (NMFS 143-200001 - 46); Pt 3, USNM 1606669, 127 mm. S of Herbert Island, Islands of four Mountains, (52°32.88 N, 170°06.28 W), 238 m (NMFS 143-200001 - 32); Pt 4, RNC 4871, 170 mm. SSE of Yunaska Island, Islands of four Mountains (52°32.17 N, 170°37.47 W), 122 m (NMFS 143-201201 - 41); Pt 5, RNC 4510, 88.1 mm. S of Yunaska Island, Islands of four Mountains (52°31.59 N, 170°41.41 W), 118 m (143-200601-42).
Referred material: 1 sp., David Stanchfield Coll. 192 mm. Islands of four Mountains (52°30 N, 170°0 W) ~ 100 m; 1 sp. RNC 4749, 100 mm. S of Akutan Island, Fox Ids. (53°15.2 N, 165°24.93 W), 90 m (NMFS 143- 201501 - 2) (white shell).
Description: Mature shell large (to 192 mm David Stanchfield collection), heavy and sturdy; pyriform; tan, usually with darker cords (rarely solid white RNC 4749); periostracum thin, brown. Protoconch with 2.5 whorls, four to five teleconch whorls, first teleconch whorl with two even cords, changing to a strong carination, a subsutural cord and two strong cords below the shoulder carination. Axial sculpture lacking; mature sculpture of three strong primary cords on the shoulder ramp, and three to five strong cords below the shoulder carination (or primary cord), with secondary and tertiary cords between the primary cords; base with about ten primary cords, and secondary cords comparable to those above the suture; columellar and parietal callus broad but sharply delimited. Aperture very large, oval, more than half of shell height; canal relatively long, rather narrow.
Radula: Rachidian tooth broad, roughly quadrate, deeply indented anteriorly, bearing three subequal cusps, the central cusp slightly longer and slenderer than the outer two. Lateral teeth large, heavy, tri-cuspid; outer cusp much larger than inner two, thick, curved; central and inner cusps close together, widely spaced from outer cusp; inner cusp about half the size of the outer one, relatively thick, only slightly bent; central cusp slightly shorter and more slender than inner cusp, also slightly bent.
Remarks: This species is characterized by its large size, large aperture, broad profile and early emergence of two or more additional primary cords below the shoulder cord. It is quite unlike any other north Pacific species.
Etymology: Named for the NMFS chartered fishing vessel Vesteraalen that collected the Holotype.
Distribution: Found in the eastern and central Aleutian Islands, from near Akutan Island, Fox Ids. (165°24 W) to Kanaga Island, Andreanof Ids. (177°21 W). Most often taken in the vicinity of the Islands of Four Mountains, at depths of 90– 238 m.
Habitat: Sandy or muddy bottoms at temperatures of 4–4.3°C.