Description: Shell minute, depressed turbinate, broadly umbilicate; aperture and whorls circular, peritreme complete, suture deeply impressed, lip thin. Whorls 3.5; axial sculpture of weak, irregular growth increments only; spiral sculpture of variable number (49-77) of fine, narrow cords; spiral cords present throughout, from suture to umbilical walls, stronger on base, with wider interspaces on base. Color tan or whitish, rarely stained with rust. Operculum calcareous, outer surface concave, with up to 6 evenly expanding volutions in multispiral pattern.
Dimensions: Illustrated specimen: height 1.68 mm, diameter 2.46 mm. Shell height 68% of diameter.
Distribution and habitat: North Pacific Ocean: Kuril Islands (GOLIKOV & GULBIN, 1978); Aleutian Islands (LACM: Attu, Amchitka); Kodiak Island (LACM); Kachemak Bay, Cook Inlet (RB, LACM); Prince William Sound (RB), Southeastern Alaska (WILLETT, 1919); Cumshewa Inlet, British Columbia (type locality). On undersides of rocks at low tide, on gravel or muddy, shell bottoms to 30 m. Common in intertidal zone in Kachemak Bay, Cook Inlet, Alaska; more frequent in the subtidal zone in southeastern Alaska. GOLIKOV & GULBIN (1978) reported it at 20 m, Simushir Island, Kuril Islands (approximately 47°N, 152°E).
Type material and type localities: Moelleria quadrae: USNM 107411, 18-27 m, Cumshewa Inlet, Queen Charlotte Islands, British Columbia (approximately 53°N, 132°W); collected by C. F. Newcombe. Moelleria drusiana: USNM 31117, intertidal, Constantine Harbor, Amchitka Island, Aleutian Islands, Alaska; collected by W. H. Dall.
Remarks: Although DALL (1919) reported that Moelleria drusiana has the "surface smooth except for microscopic incremental lines," there are 42 fine spiral striae on the final whorl of the holotype. The holotype is clearly an immature specimen of M. quadrae, 1.1 mm in height and 1.5 mm in diameter.