Synonym: peracutum Dall, who writes: « Shell whitish or yellowish, thin, very depressed, conic, extremely sharply keeled at the periphery; sculpture faint, base rounded, excavated just within the periphery; umbilicus large, scalar, the walls in each whorl deeply concave, bordered below by a very strong nodulous rib, terminating in a sulcus at the base of the columella. Nucleus sinistral, immersed, whorls six or seven without the nucleus; sculpture above consisting of numerous radiating somewhat flexuous fine incremental lines crossed at the periphery by one strong flattened spiral thread, nodulous on the earlier whorls and articulated faintly with yellowish brown. Inside this is a much finer simple spiral, and within this again another large one, also nodulous on the early whorls. Hence to the suture are four or five smaller flattened spirals, uniform, but fainter on the later whorls and separated by somewhat wider faintly but distinctly channelled interspaces. Periphery of the shell brought to a thin but rounded carinal edge, which is however about the sharpest of any known in the genus. » – W. H. Dall: “Reports on the results of dredging, under the supervision of Alexander Agassiz, in the Gulf of Mexico (1877-78) and in the Caribbean Sea (1879-80), by the U.S. Coast Survey Steamer ‘Blake’, Lieut.-Commander C.D. Sigsbee, U.S.N., and Commander J.R. Bartlett, U.S.N., commanding. XXIX. Report on the Mollusca. Part 2, Gastropoda and Scaphopoda”, Bulletin of the Museum of Comparative Zoölogy at Harvard College vol. 18, Cambridge 1889, p.275.

« Base sculptured by numerous fine spirals, by strong but irregular radiations from the umbilical margin, which is marked on its edge vith about 22 strong nodules, and bordered by two grooves enclosing a wider subnodulous spiral space, becoming less marked with age. Columella short, thickened, with a sulcus at its base; basal margin thickened near the sulcus; the remainder of the apertural margin thin and sharp, the aperture itself almost triangular. » – Ibid.