Description. Shell of moderate size for genus, to 43.4 x 16.2 mm, fusiform, slender, with about 10,5 whorls, elevated spire, elongate siphonal process and scattered sutural lamellae. Protoconch of about 2,5 whorls, first whorl globose, tip immersed, second whorl not much wider than first, with slightly convex sides and about 4 faint axial riblets near terminus. Teleoconch of about 8 convex whorls separated by deeply impressed suture and sculpted with prominent axial ribs and spiral cords and with sparse axial lamellae scattered on rudimentary sutural ramp; axial ribs of all whorls broad, node-like, extending from anterior suture to posterior sutural ramp; 5 spiral cords on early whorls, of nearly equal size on whorl 1; middle 3 cords becoming stronger on whorls 2-4; all cords strong on whorls 5-7. Body whorl somewhat shouldered, with 2 or 3 very prominent cords at periphery; 2 or 3 more cords diminishing in strength apically and 3 or 4 cords diminishing in strength toward base; surface of spire and body whorl with many fine, axially aligned microlamellae and as many as 6 spiral threads in interspaces between cords; about 12 oblique cords, some separated by fine threads on base and siphonal process. Aperture subovate; outer lip highly arched, thin, crenulated at edge by spiral cords and interspaces of body whorl, inner side of lip with 8 or 9 smooth, emergent lira extending to lip edge; columella gently curved, with about 2 faint folds near anterior end; parietal shield smooth; siphonal canal slender, smooth within, twisted near middle to form small pseudoumbilicus near anterior end. Protoconch and exterior and interior of fresh shell pure white; older shell fading to cream. Operculum and radula unknown.

Etymology. From the Latin eburneus, an adjective meaning "ivory-colored," referring to the pure white shells whose colors fade to cream like old ivory as they age.

Remarks. Shells of L. eburneus differ from those of L. ceramidus by having a relatively taller, more slender spire and more scattered and sparse axial lamellae. The shell surface of L. ceramidus is nearly smooth, whereas that of L. eburneus has strong spiral cords on all whorls; the two or three large cords crossing the tops of the axial ribs characterize the species. Differences with other species are discussed in accounts that follow.
The 24.9-mm Venezuelan shell is too old and worn to be included as a type.

Venezuela and Colombia, southern Caribbean Sea; depth range 150-195 m.