Type material. SW of Chirkof Island, SE of Semedi Island, Alaska (54° 58.70' N, 157° 18.16' W), F/V Dominator, NMFS Gulf of Alaska Trawl Survey, sta. 23-991-78, R.N. Clark, 3 June 1999, 167 m, holotype LACM 3455, 16.3 mm, lv.
Distribution. Only known from the holotype.
Description. Shell small for genus, 16.3 mm in length, partially broken. Slender in shape, biconical, weakly spinose, lightly built; subsutural ramp moderately broad, weakly sloping, weakly concave. Shell color entirely white. Spire high, with five or more, broad, weakly convex, strongly shouldered, lamellately sculptured teleoconch whorls; suture impressed. Protoconch, first whorls eroded. Axial sculpture of teleoconch whorls consisting of high, thin, fragile lamellae, more strongly developed at shoulder, producing narrow, broadly open, adapically projecting spines. Other axial sculpture of low, weak, narrow growth lamellae. Last teleoconch whorl with nine lamellae; penultimate, previous whorls with 12-14 lamellae; first, second whorls eroded. Spiral sculpture of low, rounded, broad, smooth, primary cords. Last teleoconch whorl with P1, P2, s2, P3, P4, P5, weak, very small ADP; P1 broadest, P2 smaller, P3-P5 similar in strength. Previous whorls with visible P1—P2, P3 partly covered by subsequent teleoconch whorl. Intersection of spiral cords with axial lamellae producing small, broad spines, chiefly on last teleoconch whorl. Subsutural ramp smooth except low, flattened axial lamellae. Aperture broad, ovate; columellar lip narrow, smooth, lip adherent. Anal notch shallow, broad; outer lip erect, thin, smooth within. Siphonal canal partly broken, narrow, broadly open ventrally, with weak, narrow ADP.
Remarks. Nipponotrophon magnificus (Golikov & Sirenko, 1992) from the Kurile Islands has higher spire whorls with less obvious P2 cord on early whorls, absent P2 and P4 cords on last whorl, and a more strongly sloping and broader subsutural ramp.
Etymology. Exquisitus (L), meaning excellent, exquisite, a beauty.