As Balcis pervegrandis:
Shell of moderate size, subulate, translucent white, smooth and glossy. Spire tall, 2 ⅝ times height of aperture, erect, straight sided, slowly tapered except over the first four post-nuclear whorls, which increase rapidly following a small three-whorled mucronate protoconch with a minute apex. Whorls 12 including the protoconch, slowly increasing at first, but later accelerated so that the body-whorl occupies exactly half the height of the adult whorls (minus protoconch). Suture linear, false margined. Aperture narrowly pyriform. Outer lip thin and sharp.

Height, 10·6 mm.; diameter, 2·5 mm. (holotype).
Holotype in writer's collection, Auckland Museum.
Localities: 23 fathoms off Ahipara (July, 1925) (holotype); 25 fathoms off Hen and Chickens Islands (Dr. H. J. Finlay collection).