1: 1.3mm high. September 2015. Early juvenile that metamorphosed in July or August when about 0.3mm high.
2: 2.9mm high. March 2016. At start of growth, after winter pause, in specimen’s first spring.
3: 6.2mm high. March 2016. At start of growth, after winter pause, in specimen’s second, and final, spring.
4: breadth 49% of shell height.
5: breadth 34% of shell height.
6 :small aperture, height 21% of shell height (range 20% to 34%).
7: body whorl 36% of shell height.
8: sutures between slightly swollen whorls appear deep as they coincide with furrows between spiral ridges.
9: apical angle about 30º.

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