Juvenile L. littorea:
Inset at 2X main scale.
1: Patch of wrinkled periostracum. Usually so thin and closely adhering that it escapes notice on adults, and is frequently eroded off.
2: Periostracal fragments on thin, fluted, banded palatal lip.
3: Bristle-like projections of periostracum forming white crest on ribs; regularly occur on juveniles.
4*: Narrow spiral ribs with sharp raised adapical edge; distinctly different from L. compressa but might be mistaken for those on some L. arcana and L. saxatilis s.s.
5*: Dark spiral lines on ribs (frequent on juv. L. littorea) may cause confusion with nigrolineate forms of L. compressa but its dark lines are usually in its grooves.
6: Pure white columellar lip, often has vitreous lustre; distinguishes L. littorea from L. saxatilis and L. arcana (their lips may be off-white or tinted with other colours).
7*: Dark patch where banded palatal lip adjoins pure white columellar lip; distinguishes L. littorea from L. compressa.
8. Shell of earliest stage of L. littorea is usually whitish without pigment; survives as whitish apex on later stages unless eroded off.