The shell is large for the subfamily (maximum length 38 mm) and coarsely biconic. The spire is high and acute, consisting of two and one-fourth convex nuclear whorls and six or seven angulate
postnuclear whorls. The suture is moderately im-pressed and obscured. The body whorl is mod-erately large and roughly trigonal. The aperture is subcircular, moderately small, and entire at the weakly erect peristome. Each anal siphon empties through a moderately long, dorsally directed, hollow tube that arises somewhat nearer the preceding varix; the tube is appressed to, and apparently buttressed by, a flangelike portion of die preceding varix, the partition, this connecting the whorl with the preceding one. The completely sealed siphonal canal is broad for the upper three-fourths of its length: the distal one-fourth of the canal is slender, tubular, and dorsally bent.
The body whorl bears four varices; the three earliest of the four are heavy, rounded, and rope-like: the last is alate, with a moderately broad flange extending from the preceding whorl to be-low the middle of the canal, and is reflected dorsally at its free edge. The varix is drawn into a moderately long, sharp, dorsally incurved spine at the shoulder margin. Spiral sculpture consists of five cords on the body and seven on the canal; although prominent on the varices, these cords vary from strong to obsolete in the intervarical spaces. Shell color is white, with orange-brown suffusions on the varices, purple-brown on the tubes and on the tip of the siphonal canal, and porcelaneous white in the aperture; four or five red-brown spots on the last outer apertural lip margin also persist just in front of each of the former outer lips.
The winglike varical flange is apparently the last part of each growth increment to be formed, since a slender form, found in many collections and lacking a varical flange, is otherwise apparently mature.
Puerto Penasco. Sonora, Mexico, to Santa Elena, Ecuador.