Young small shells of S. cineraria, with low profile, relatively widely spaced bands and open umbilicus are often mistaken for S. umbilicalis. In a sample of 71 shells of S. umbilicalis and S. cineraria, from sites between north coast Scotland and south coast England, the average number of bands within each width category on S. cineraria was approximately double the average on S. umbilicalis, with no overlap in the ranges. Bands were counted around the periphery of the body whorl, including part of the outer lip to complete the circuit. Examples:
Width 14 mm to 15.9 mm
S. umbilicalis mean 22 bands (range 18 –31 bands).
S. cineraria mean 52 bands (range 35 –68 bands).
Width 12 mm to 12.9 mm
S. umbilicalis mean 17 bands (range 13 –23 bands).
S. cineraria mean 41 bands (range 34 –49 bands).
Width 5 mm to 8.9 mm
S. umbilicalis mean 10 (range 7 –13 bands).
S. cineraria mean 25 (range 19 –29 bands).