Shell of medium size, up to 33 mm in height, similar to pulchella typical in its granular spiralled surface sculpture, but with a much more prominent spinose-armed keel, which is margined above by a wide scabrous to finely spinose-spiralled flat area, beyond which is a concave deeply sunken smooth sinus area, extending to the Suture. The peripheral spines number 19 on the last whorl in the holotype; they are long, narrowly triangular, very sharply pointed, upcurved over the early whorls, but horizontal to slightly depressed over the last whorl. There are 7-8 finely beaded, linear-spaced spiral cords from the peripheral carina to the lower suture on the last two whorls, and about 34 on the base and rostrum. The protoconch is small smooth and vitreous of 1,5 whorls, the tip slightly oblique. The sinus is deep with a rather broadly rounded apex, and occupies the entire smooth shoulder sulcus. Colour white under a very thin pale butt periostracum; the smooth sinus area silvery to iridescent. Range—Philippines, deep water. This subspecies occurs on green mud and grey mud with fine sand, from 159-385 fathoms.