Shell moderately large, thin but sturdy, white, spire high, canal long, recurved, open; length of aperture and canal slightly greater than height of spire, aperture shape quadrate, canal constricted. Protoconch eroded, teleoconch whorls six, early whorls bulging at midwhorl, having about 12 thick axial ribs. Mature sculpture of 10 to 13 axial lamellae, suppressed on the shoulder, at the periphery producing open, raised spines that rise above the level of the suture; lamellae sharply raised on the body whorl but suppressed on the siphonal canal; siphonal fasciole with overlapping lamellae; axial sculpture lacking. Aperture simple, lacking denticles or columellar callus. Dimensions: height 49.4 mm, diameter 26.1 mm (holotype).
Radula: typical for the genus, rachidian plate broad and shallow, having five cusps, a strong central cusp and two on either side, the outermost the larger; lateral teeth sickle-shaped.

A species of Trophon characterized by its quadrate aperture, and sculpture of axial lamellae, which are spinose at the periphery. It most resembles Trophon (Stramonitrophon) plicatus (Solander in Lightfoot, 1786), a common shallow-water species from southern Chile in which spiral sculpture is lacking, but is smaller with the aperture more quadrate and the canal more constricted. The two species are not closely related, for Trophon plicatus has a unique radula in which there are accessory cusps (the feature upon which the subgenus Stramonitrophon is based).

TYPE LOCALITY. 340 m off Pichilemu, Chile (34°27'S).
DISTRIBUTION. Coquimbo (29°58'S) to Pichilemu (34°27'S), Chile. Depth range: 200-450 m.