08 Myosotella myosotis form denticulata.

08 Myosotella myosotis form denticulata.

Usually, the shell has no visible umbilicus by the aperture, but there is an umbilicus-like slit (1) in the apex caused by the change from the sinistral larval shell (protoconch) to a dextral shell.
Shell height 3.5 mm. Salting on tidal River Dee, Flintshire, Wales. December 2018.

marinvert.senckenberg.science/image-browse/