Shell (holotype) small for the genus, 9.90 mm high, height/width ratio 2.00, spire height 43% of shell height, uniform white. Protoconch of 1.5 smooth, convex whorls, 780 µm wide, clearly demarcated. Teleoconch of 4.3 convex whorls, shoulder angulation supramedian on first whorl, gradually descending to median position, shoulder slope broad, more or less flat, steepening with increasing size; side shallowly concave, abapically narrowing; base broadly convex, smoothly transitioning to posterior siphonal canal. Axial costae strong, angulate in section, interspaces concave, each costa surmounted by single thin commarginal lamella and single short, open spine, numbering 10 on first whorl, 9 on second whorl and 9 on third whorl. Spiral sculpture represented by very poorly defined P1 at shoulder on first whorl, elsewhere obsolete on spire, last adult whorl with 2 additional low spiral swellings (P2 and P3) that form rounded nodules at intersections with axial costae on last half whorl. Aperture ovate; inner lip smooth, entirely adherent; outer lip smooth and moderately thickened within, no posterior notch. Siphonal canal of moderate length, fasciole with commarginal lamellae. Etymology. Small (Latin).

Enixotrophon pumilus differs from E. lata (Marshall & Houart, 2011) in having less obvious axial lamellae, shorter and narrower spines at shoulder, a relatively higher spire and shorter siphonal, and a more steeply sloping infrasutural ramp. From the other Enixotrophon species occurring in the New Zealand region, all illustrated by Marshall & Houart (2011), E. pumilus differs in having obsolete P2 and P3 cords that are barely visible where they cross the axial costae, a more globose and broader last teleoconch whorl, and in having a relatively higher spire combined with a shorter siphonal canal.

New Zealand. West Norfolk Ridge, W of Cape Reinga, 785-800 m (shell)