Lengths:
Left shell: 12mm from 19mm animal, shell 63% of animal length.
Centre shell: 19mm from 30mm animal, shell 63% of animal length.
Right shell: 15mm from 25mm animal, shell 60% of animal length.

Weakly calcified, fragile shell is colourless semitransparent (1), or clouded translucent white (2). Very large body whorl forms over 90% of the shell. Two small, but rapidly expanding, spire whorls meet at a deep suture (3). The small spire distinctly protrudes (4) beyond the outer (palatal) lip of aperture in abapertural view. Llŷn Peninsula, Wales. March 2016.