Original description.
Shell sinistral, small, broadly elongate, conic, dark brown. Nuclear whorls four, light brown, increasing regularly in size, provided with spiral and axial sculpture (but this is too badly worn to l)e properly diagnosed in all our specimens). Post-nuclear whorls eight, separated by channelled sutures. The first four post-nuclear whorls have a double spiral row of tubercles, the posterior row being a little more strongly developed than the anterior. These rows are separated by a channel about as wide as the tubercular ridges. Beginning with the fifth whorl, a slender tuberculate cord appears in the middle of the channel which separates the two spiral ridges; this grows steadily in size with each turn, until on the last volution it is quite as strong as the suprasutural cord. On the later turns the middle and suprasutural spiral cords and their tubercles fall off quite abruptly at their posterior border and slope roundly toward their anterior limit. The tubercles on all the turns are joined by rather wide spiral bars and axial ribs, which inclose deep squarish pits between them. Periphery and base of the last turn well rounded, the former marked by a low somewhat flattened keel, which is separated from the supraperipheral cord by a channel as wide as the one which separates the supraperipheral J^eel from the middle one. The channel is crossed by the extension of the axial riblets. The base is marked by two spiral cords about as broad and of the same character as the peripheral one. These cords are separated by channels as broad as that which separate the peripheral cord from the supraperipheral one and are crossed by feeble extensions of the axial riblets. The anterior basal cord is situated upon the base of columella and its anterior border fuses almost imperceptibly with it. The entire sur- face is crossed by many exceedingly fine spiral striations and lines of growth. Aperture subquadrate, posterior angle obtuse, anteriorly strongly channelled; outer lip subpatulous anteriorly, not sinuous; columella short, thick, twisted. Columella and the parietal wall are covered with a strongly developed callus.