Snail shells are said to be “scalariform” when anomalous growth causes the whorls of the spire to more laxly coiled and the spire, thus, appear longer than typical. The protoconch and early teleoconch whorls of this shell are missing or damaged which may suggest a cause for this deformation. A normal shell of Cepaea nemoralis is much more nearly globular.
A nice photograph of another scalariform C. nemoralis appears in this website: http://molluscs.at/gastropoda/index.html?/gastropoda/morphology/scalariform.html
A normal C. nemoralis is shown below.