flected, inflected or lipped edge, which is sometimes more or less contracted by inflected calcareous projections known as teeth. These teeth may be outer lip teeth, columellar teeth or parietal teeth.
Folds or plicae are named by their position in the aperture, as follows. The numbers refer to those in the diagram shown opposite:
Folds or plicae
- upper palatal
- lower palatal
Lamellae are named as follows:
- angular and twin
- "Aperture shape Bean". accessed 3 January 2011.
- "Aperture shape Crescent". accessed 3 January 2011
- "Aperture shape Half-moon". accessed 3 January 2011.
- "Aperture shape Oval or teardrop". accessed 3 January 2011.
- "Aperture shape Round". accessed 3 January 2011.
- "Aperture shape Taller than wide, top angle acute". accessed 3 January 2011.
- Pilsbry H. A. & Cooke C. M. 1918-1920. Manual of Conchology. Second series: Pulmonata. Volume 25. Pupillidae (Gastrocoptinae, Vertigininae). Philadelphia. Page vii.