Vexillum leucaspis: Fusiform shell, small for the subgenus, reaching about 7 mm in length; width about 40% of length. Papillose paucispiral protoconch (1,5 translucent brown whorls). Teleoconch consists of 5 slightly convex whorls. Straight spire outline. Each whorl with about 12 smooth axial ribs with very slight nodules at the shoulder. Suture well defined. Aperture about half of the entire shell. Columella with 4 folds, elongated as spiral ribs on the siphonal fasciole. Siphonal canal short and wide, slightly recurved. Colour pattern: Shell dark brown. Axial ribs greenish brownish and lighter than the dark brown interspaces. Lower half of the spire whorl ribs and middle third of the body whorl ribs covered with a white rectangle. All colours also visible within the aperture at outer lip. Columellar folds whitish to brownish.

Vexillum leucaspis: Vexillum (Pusia) leucaspis n. sp. is similar to V (P)strictecostatum (VON MALTZAN, 1884) from the same geographical area. But the number of axial ribs in the new species is only half of that in V (P) strictecostatum (12 vs. ~ 20). According to MALTZAN (1884) this species is coloured uniformly reddish-brown,whereas in V (P) leucaspis n. sp. the interspaces are darker than the ribs with the typical white rectangle, which is not present in V (P) strictecostatum. Colour variants of the latter species also have lighter broad subsutural bands, sometimes with unique rows of dark dots, but those areas are not pure white and there is no difference between rib and interspace colouring. Two syntypes of V (P) strictecostatum and 10.5 mm) are deposited in Berlin (MfN). Type locality is Senegal, Goree Island.

Vexillum leucaspis: Holotype: Senegal, Dakar, Les Almadies, 3-5 m in sand, collected 1994, 7.0 mm x 2.6 mm, ah: 3.0 mm, SMNS-ZI-0073917(ex GS).
Type locality: Senegal, Dakar, Les Almadies, 3-5 m in sand.
Distribution: Only known from shallow water of the Atlantic Ocean off Dakar, Senegal.