Shell tall, elongated, semi-transparent and glossy with many whorls. Dead shells whitish. Apex crowned by prominent protoconch forming an angle of about 120 to shell's main axis. Initial whorls, more or less straight in profile, later whorls become increasingly more convex. Suture is clear but not very deep, forming an angle of 75-85 to shell's axis. Smooth, except for occasional, more or less orthocline, growth lines. Protoconch of type A-II, measuring about 220 μm, forming an angle of about 115 to the shell's main axis. Aperture more or less rectangular-rhomboid. Outer lip starts below periphery, perpendicular to surface of last whorl. It curves towards the base, following nearly straight course until below the periphery, where it curves towards columella, forming slight spout. Columellar lip, slightly concave, forming prominent fold 28 at its base. Inner lip concave, ending in prominent columellar fold. No umbilicus and weak umbilical groove. 4-5 riblets on inside of outer lip of the same type found in, for example, Megastomia. Dimensions: Holotype with 12.5 teleoconch whorls, height 5.3 mm. Type locality: Ivory Cost, Region of Abijan, dredging on the continental shelf.
Distribution: Only known from Senegal and Angola. Etymology: The species is named for the presence of riblets within the outer lip. Remarks: Eulimella endolamellata n. sp. resembles Eulimella laevis (Brown, 1844) , E. ventricosa (Forbes, 1843) from northern Atlantic and the Mediterranean Sea and E. variabilis (De Folin, 1870) from West Africa. These species, however, lack both the riblets inside the outer lip and the prominent columellar fold on the columella. Some specimens of E. neoattenuata Gaglini, 1992 from San Vito, Sicily (in the Monterosato collection in Rome) show weak riblets inside the outer lip, but the brown spiral bands clearly distinguish these specimens from E. endolamellata.

This species can be recognised immediately by its very low whorls. There are four or five list-like teeth on the inside of the outer lip. Such teeth are only rarely found in Eulimella species (see the note with Eulimella).