Several species are superficially similar, but close inspection (and attention to habitat) will usually rule them out fairly easily. A selection is given below.
Odontoschisma denudatum
Matchstick Flapwort
Explore this species
Biantheridion undulifolium
Marsh Flapwort
Explore this speciesSyzygiella autumnalis
Autumn Flapwort
Explore this species
Nardia scalaris
Ladder Flapwort
Explore this species
Solenostoma gracillimum
Crenulated Flapwort
Explore this species