Nebularia proscissa: Shell up to 38 mm (about 1,5 inches) in length, elongate-ovate, moderately solid, sutures more distinct than in either M. cucumerina or M. chrysalis. Whorls 7-9, apart from 1,5 smooth, conical nuclear whorls, first 2 postnuclear whorls finely clathrate, latter whorls with narrow or moderately broad but shallow spi-ral grooves which give rise to flat or slightly elevated spiral cords; the cords number from 3-7 on the penultimate and from 14-22 on the body whorl. On the centre of the last whorl, the interspaces may become either very narrow and groove-like or as wide as the spiral cords themselves; the cords are less regular than in M. cucumerina or M. chrysalis, and at the suture 2 cords are doubled up, with the sutural cord finer and smaller in size. The spire whorls are either flat-sided and occasionally subangulate, or weakly convex and narrowly ledged at the sutures. The aperture is longer than the spire, very narrow and smooth within; the outer lip is elongate and regularly convex, crenulate at the margin, the columella is calloused and has from 3-5, generally 4, oblique folds. The siphonal fasciole is straight and the siphonal notch distinct. Reddish-brown in colour, ornamented with darker brown in the interspaces of the spiral cords, and with a faint or distinct yellowish-white central band on the body whorl, and sometimes narrow white axial streaks or a few small spots on the cords. Some individuals are creamy-white or very pale grey, ornamented with reddish-brown, slender axial streaks and darker interspaces, and 2 broad and nebulous, interrupted and ill-defined transverse bands on the body whorl; the aperture and columella are brown or greyish-brown. Periostracum thin, brown and moderately translucent. Height 37.2 mm; Width 14.2 mm; Height of aperture 19.1 mm.

Nebularia proscissa: This species is similar to P. cucumerina Lamarck and M. chrysalis Reeve, but is larger in average size, less squat and ovate but rather elongate, with a more acuminate spire and with two of the spiral threads adjoining the sutures doubled up. The colour form porcata Reeve is more convex in outline, has a reddish-brown base colour with darker brown interspaces between cords, and a yellowish-white central band on the body whorl and occasionally narrow, white axial streaks. The typical form proscissa has slightly more subangulate whorls, the base colour is creamy-white or light grey and ornamentation consists of dark reddish-brown axial streaks and 2 nebulous, faint, broad bands on the body whorl. The latter form is more frequently encountered in India, but both forms are sympatric in Queensland, Australia. Reeve's 3 syntypes of N. proscissa consist of 1 typical specimen and 2 specimens of the porcata form.

Nebularia proscissa: Range—Gulf of Oman to China and the Fiji Islands. On reefs, sometimes in muddy localities, under rocks and coral of the intertidal zone.