04 Testudinalia testudinalis. Littoral. Moray Coast, Banffshire, Scotland. May 2017. Leg. S. Taylor.

04 Testudinalia testudinalis. Littoral. Moray Coast, Banffshire, Scotland. May 2017. Leg. S. Taylor.

Interiors of shells shown in image 01 Testudinalia testudinalis. Littoral. Moray Coast, Banffshire, Scotland. May 2017. Leg. S. Taylor. (These are wet; colours are brighter than when dry.)
Lengths: 1) 11.6mm 2) 12.1mm 3) 13mm 4) 13.2mm 5) 14.2mm 6) 12.1mm 7) 13.9mm 8) 12.2mm. Anteriors orientated upwards.
Aperture rim an ellipse; posterior and anterior usually similar breadth.

APPENDIX re range advance/retreat: flic.kr/p/2jW74ig

marinvert.senckenberg.science/image-browse/