Fusiform shell, width c.45% to 55% of height .
1 to 4: shell height.
1 to 3: body whorl height; c. 73% of shell height, usually a little less on small specimens..
1 to 2: aperture height. 3 to 4: spire height.
5: apex slightly twisted due to change from white, sinistral protoconch to dextral teleoconch.
6: growth lines; most easily seen when periostracum is worn.
Data of specimens, from left to right of image:
Height ___6.4 mm __5.8 mm 5 mm 6.4 mm
Width ___3.2 mm __3.1 mm _2.6 mm 3.1 mm
W/H% ____50% ___53% __52% __48%
BodyWhorl 4.8 mm 4.3 mm 3.6 mm 4.7 mm
B/H% ____ 75% __ 74% __ 72% __73%
spire/H% __25% __26% __28% __27%
Aperture _3.4 mm 3.3 mm 2.9 mm 3.6 mm
A/H% ____53% __57% __58 % __56%
Heights 6.4 mm to 5 mm. Under stones embedded in soil-like sediment at EHWS. From three shores in Menai Strait, Wales.