Left: Gibbula umbilicalis, breadth 6.5mm, August 1969, NW coast Scotland.
Right: Gibbula cineraria, breadth 6.5mm, Aug. 2013, Menai Strait, Wales.
Umbilicus on G. cineraria almost as circular as on G. umbilicalis when small.
Left: Gibbula umbilicalis, breadth 6.5mm, August 1969, NW coast Scotland.
Right: Gibbula cineraria, breadth 6.5mm, Aug. 2013, Menai Strait, Wales.
Umbilicus on G. cineraria almost as circular as on G. umbilicalis when small.