Pusia vassardi: Diagnosis
Shell small to medium sized (13-14 mm), broadly fusiform. Suture deeply impressed, spire slightly acuminate, with spire whorls flattened in outline. Axial sculpture of dense rounded ribs with narrow interspaces, well pronounced on spire whorls; ribs widened on last adult whorl, vanishing below periphery and on latest half of whorl. Interspaces between axial ribs sculptured with low rounded cords on early spire whorls, the pattern changes later to multiple fine grooves, very weak on last adult whorl. Siphonal canal short, tapering. Aperture elongate, its outer lip lirate within, inner lip with strong callosity, bearing four strong columellar folds, adapicalmost fold strongest. Shell orange to light brown, with darker spire and lighter spiral band along periphery of penultimate and last adult whorls.

Description
Shell small to medium sized, broadly fusiform (w/h 0.43; a/h 0.51), with slightly acuminated spire. Protoconch missing or worn in all specimens studied. Suture distinct, deeply impressed. Teleoconch of about 7.5 whorls, spire whorls with flattened profile, sculptured with multiple, rounded orthocline ribs (30 on fourth adult whorl) with narrow interspaces. Axial ribs forming weak subsutural 'caps' on early spire whorls, interspaces between axials with five or six closely set, broad, rounded cords that are more pronounced on early spire whorls, and become indistinct, with only shallow grooves remaining, on later whorls. Axial ribs broadened on penultimate and last adult whorls, not pronounced below periphery and on latest half of last adult whorl. Spiral grooves also very weak on adapical portion and periphery of last adult whorl. Shell base gradually extending towards short, tapering siphonal canal, sculptured with three very weak, vaguely gemmate, spiral cords. Siphonal fasciole with three strong rounded cords. Aperture elongate, with evenly convex outer lip, slightly extended towards tip of siphonal canal, lirate within. Inner lip with strong callosity, bearing four strong columellar folds, adapicalmost fold strongest, subsequent folds gradually weakening. Shell orange to light brown, with darker spire and lighter spiral band, widened on crests of axial ribs, at periphery of penultimate and last adult whorls.
Radula about 0.12 mm wide. Rachidian with wide base and three closely set cusps, rather short and stout. Laterals strong, sickle shaped, unicuspid.

Pusia vassardi: Pusia vassardi resembles the type species Pusia microzonias as well some Pusia (Vexillena) species, like Pusia balutensis, Pusia jenyai , and Pusia dautzenbergi, primarily in shell proportions and colour pattern; however, Pusia vassardi can be easily distinguished from Pusia microzonias by its lighter and stouter shell with proportionally higher last adult whorl. Pusia vassardi is easily separated from species of Pusia (Vexillena) by the characteristic dark spire and weakly sculptured last adult whorl. Apart from that, Pusia vassardi can be readily distinguished from Pusia balutensis by the smaller shell, flattened outline of spire whorl, and notably widened axials on last adult whorl, and also by the dark color of the spire. Similarly, Pusia jenyai is recognized by its distinct, though very wide and flattened, axials that extend to shell base. Pusia dautzenbergi has a higher spire and stronger axials; however, paratype 5 of the latter species from the Philippines shows an extraordinary resemblance to Pusia vassardi
Finally, Vexillum geronimae resembles Pusia vassardi in proportions and colour pattern, but the robust base and deeply notched siphonal canal, commonly found in true Vexillum species, are distinctive.

Pusia vassardi: Known only from Southern Madagascar, in shallow water, depth range 15-24 m.