Shell small (to 15.6 mm in total length), fusiform, truncated anteriorly, up to 10 slightly convex to moderately convex whorls, suture undulates over rib ends, last whorl approximately 60% of total shell length. Protoconch of approximately 2 smooth whorls, first not immersed in second, second large, its peripheral diameter greater than the first teleoconch whorl at suture. Axial sculpture of broad ribs but their width less than the intercostal space, relatively few in number, 6-8 on penultimate, 4-6 on last whorl to varix, tend to align whorl-to-whorl. Last rib before varix sometimes incompletely formed—narrower or shorter than previous ones. Ribs run suture-to-suture on spire whorls, slightly reduced in sulcal area; crests round. Varix an expanded last or penultimate rib with up to 3 post-varical axial folds or axial folds, the last, on lip edge, follows the contour of the lip from the suture to stromboid notch. Spiral sculpture of evenly-spaced incised lines over entire shell, closer in sulcal region, stronger and ridge-like on shell base. Sulcus absent, lower ribs and more closely spaced incised lines present on whorl shoulder. Outer lip thin, somewhat flattened from varix to lip edge forming a low sigmoid arc from the anal sinus to the anterior canal, with a slight dip for a stromboid notch. Anal sinus only a slight indentation of the outer lip beginning at the suture, when viewed laterally; inverted V-shaped with inner callus on both parietal wall and outer lip of mature specimens, when viewed ventrally. Inner lip emarginated, thickened posteriorly into a low callus at its junction with the outer lip. Anterior canal open, deep, and notched; anterior fasciole not swollen, bearing 5-8 spiral ridges. Color white, pink and light brown specimens are known; also white with areas flushed with pink, or white with faint brown spots on whorl shoulders.

Coastal areas and islands of northern South America: Colombia (Magdalena Dept.); Venezuela (Margarita, Coche, Cubagua, Tortuga, and Chimana Grande Is.); Trinidad and Tobago Is.; Guyana and Suriname (Guyana Plateau). Specimens have been reported taken from 4.6 m (Chimana Grande I.) and from 30-80 m depths elsewhere. They have been reported from on coralline sand (Colombia), and muddy sand (Guyana Plateau). The shallow water specimens close to the Venezuelan coast are more heavily spirally ridged, probably an adaptation to a sandy, higher energy environment. The shallow water (4.6 m depth) Cubagua I. specimens are from a sheltered habitat.
Bellaspira margaritensis appears to be confined to the shallow coastal shelf, its coastline and islands, and absent from the offshore islands. Specimens reported from the offshore islands of Curasao, Bonaire, and the Sotaveto Is. by Diaz & Puyana (1994: 225, pi. 67, fig. 892) should be verified. Specimens identified as Splendrillia sp. by Jong & Coomans (1988: 113, pi. 43, fig. 598) but said instead to be this species by Diaz & Puyana (1994: 225), are not on the basis of the specimen shown in their figure 598. No other evidence has been found that B. margaritensis occurs in the Netherlands Antilles, or any other offshore island not connected to the South American continental shelf. The report of the occurrence of B. margaritensis off Barbados by Sander & Lalli (1982: 317) have been determined to be B. barbadensis, new species, on examination of their specimens in the ANSP. Specimens have been examined from most but not the entire range in published reports of the species. The photograph in Massemin et al (2009) appears to be this species and if so extends its range to at least as far south as the Guyana and Suriname plateau (in 40-80 m, on muddy sand). Specimens tentatively identified as this from the Gulf of Mexico by Ode are unlikely this species.

The 54 examined specimens have an average length of 11.16 mm (8.3-15.6 mm) and average W/L ratio of 0.391. Shells vary in form, some narrower than others. Color varies with white being the commonest and pink specimens being occasionally found. A light brown specimen from an island near Puerto La Cruz, Venezuela has faint brown spots on rib shoulders. Specimens from Chimana Grande I., Venezuela are shades of brown in color and have stronger spirally incised lines that are heavily ridged. These differences are not believed to rise to the specific level. Identification. Bellaspira margaritensis should not be confused with any of its congeners, and is easily distinguished from other drilliids of the same size and color, such as Fenimorea nivalis, new species by its distinctive anal sinus. Bellaspira barbadensis, new species, usually found at greater depths, is very similar to B. margaritensis but differs in having more inflated whorls (sulcus is more obscure) and has different coloration.

According to McLean & Poorman, holotype large for genus, protoconch with 2 smooth rounded whorls, teleoconch with 8 whorls and 7 axial ribs aligned from whorl-to-whorl, evenly rounded and without a subsutural channel; spiral sculpture of well-spaced incisions, more closely spaced in the subsutural area. Parietal callus well defined; edge of lip thin with a minor rib, penultimate rib strongest; color white-pinkish on whorl periphery. This and examined specimens all have the characteristic anal sinus, spiral incised lines, and ribs that extend from suture-to-suture with only the slightest change in the sulcal area, and ribs number 7, usually aligned along all whorls, but not always