Shell of medium size, up to 18.8 mm in length, elongate-fusiform, solid, protoconch mamillate consisting of 3 to 3,5 smooth, transparent, glassy white whorls. Teleconch of 8 to 9 whorls; suture distinct, deeply incised, whorls slightly convex, early whorls with 11-12 close-set, strong axial ribs, interspaces with 4-6 fine spiral grooves which do not bisect the axial ribs, interspaces are "V" shaped. Body whorl with 12-14 axial ribs, interspaces with 11-12, wide spaced, short, deep spiral grooves, axial ribs extend to the lower columella where they terminate on a large round spiral cord that emerges from the first columellar fold, axial ribs and spiral grooves become reduced and nearly obsolete on the dorsal side of the body whorl just before reaching the outer lip, siphonal fasciole 3 to 4, round spiral cords of various sizes, parietal region with a thin, faint white callus in adult specimens, aperture much shorter than spire, lirations deep within aperture and apparent only near the siphonal canal, outer lip thin, simple and smooth slightly crimped near the siphonal canal; siphonal canal short, wide, slightly recurved; siphonal notch shallow, columella with four thin columellar folds decreasing in size anteriorly, columellar folds are the same color as the columella. Color on early whorls yellow with a narrow white band, later whorls a deep orange to red orange with a double-wide white band, lower columella light orange, aperture color matches that of the body whorl. Live animal : Foot transparent white with large white spots, some small dark and yellow spots especially near the posterior portion of the foot, siphon transparent with small white and dark brown streaks, eye stalks dark brown at the base with black eyes, becoming cream white above the eye all the way to the tip.

Vexillum palauense is compared to Vexillum radius (REEVE, 1845). The two species are of nearly the same length when adult (~19.0 mm vs ~22.0 mm). This new species has a more obese body whorl. It is not as elongate and the spire is less acuminate. In adult shells, there are more axial ribs on the body whorl (12 to 14 axial ribs vs 10 to 12). There are deep spiral grooves between the axial ribs of both species. The sculpture of V. radius consists of fewer spiral grooves with the axial ribs more widely spaced. The aperture of this new species is wider, the siphonal canal not as elongate. The colors of these two species are quite different, V. palauense being dark orange to red orange, V. radius is straw colored. Both species have a white band at the periphery of the shell. V. radius has a white tip while the new species has a solid color to the tip of the shell.

Type Locality
Palau, Koror State, Malakal, at a depth of 18 to 25 m.
Habitat and Distribution
This species has been collected on silty sand inside lagoons at a depth from 12 to 25 m. Only known from the Southern Palau Islands.