Two or three of these threads, in line with the sinus on the shoulder between the upper keel and the suture, are somewhat stronger, more regular, and swollen than the rest.

The surface is almost free of spiral threads just below this point, where the lines marking the lower edge of the sinus run.

The apex consists of 1¼ embryonic whorls, which are globose, smooth, and slightly obliquely pressed down on one side at the extreme point.

The aperture is club-shaped, being oval above with a sharp angulation at the upper point, and prolonged into a long, relatively narrow, but slightly widening siphonal canal, which is open due to the oblique cutting away of the columellar lip.

Above the keel lies a deep, thin-lipped, U-shaped sinus, whose lower margin is parallel to, but slightly above, the conical thread.