Size and shape comparison with similar species.
B: Barleeia unifasciata 2.9 mm high. One brown band on body whorl.
C: C. trifasciata 3.8 mm high. Three brown bands on body whorl (occasionally white with no bands). Spire whorls only slightly rounded. Spiral striae on body-whorl (may be obscure).
L: Lacuna vincta 2.9 mm high summer juvenile. Four bands on body whorl (but can be fused or absent). Spire whorls well rounded. No spiral striae.
P: Peringia ulvae juvenile 2.5 mm high. No bands.
All these species also have un-banded forms.