As Volutopsius stefanssoni Dall, 1919.
Shell large, heavy, rude, pinkish-brown with a rosy protoconch and five rapidly enlarging whorls; nucleus swollen, large, irregular, of about two whorls blunt at the apex; suture distinct, not channeled; whorls inflated, with a high rounded shoulder and five or six obscure swellings at the shoulder which do not become definite ribs; there is no spiral sculpture, but the lines of growth are rude and occasionally lamellose, especially toward the aperture in senile individuals; canal short wide, slightly recurved; aperture wide, the outer lip thickened but hardly reflected, throat whitish; body in the mature shell with a layer of whitish enamel which extends to the end of the pillar, which is arcuate, shorter than the aperture, and obliquely truncate in front. Height of shell, 114; max. diam., 65 ; height of last whorl, 87; of aperture, 75 mm. (Dall.)
TYPE in Ottawa. Type locality, Station 24, Point Barrow, Alaska.
RANGE. Arctic Ocean to Pribilof Islands, Bering Sea.

As Volutopsius simplex:
Shell large, thin, pale brown, with five or six whorls somewhat constricted at the suture; nucleus large, mammillate, of about two whorls; subsequent whorls rather convex, smooth, or marked only by irregularities of growth or incremental lines; profile fusiform, the last whorl largest but not expanded; outer lip arcuate, sharp, slightly thickened but not reflected; body without callus; pillar concave, curved to the right, twisted, short, with hardly a trace of a siphonal fasciole; canal short, wide, not recurved. Long, of shell, 101; of last whorl, 80; of aperture, 57; max. diam., 45 mm. (Dall.)
TYPE in United States National Museum, No. 110475. Type locality, Station 4792 off Bering Island.
RANGE. Off Bering Island, Bering Sea, in 72 fathoms.