Shell small, diameter between 0.4 and 0.6 mm, opaque, planispiral, of milk-white colour. Protoconch of 1/2 whorl with two spiral cords, the external one being wider and with a narrow deep canal between them.
Teleoconch between 1 and 1 1/2 whorls being on each side a spiral cord, with uniform, elevated and almost rectangular tubercles, which number approximately 15 on the first whorl. Each one is extended in axial ridges rounding the whole whorl. The periphery has another spiral cord crossed by the axial ridges but without evident tubercles. There are fine growth lines with few spiral striae between the ridges. Etymology. The specific name refers to the white colour of the shell and its spectacular aspect.

The milky white colour and the very prominent tubercles differentiate this species from the other species known from the Atlantic Ocean. A angulata Slcurs, 1985 is similar but transparent and the peripherical cord is more prominent. Also A extracarinocostata Sleurs, 1985 is transparent and its protoconch is different.