To observe this feature, turn the fruit-body over and look at the lamellae edge-on.

Choose this state if: the edge of each lamella has a split or groove, extending along the length of the lamella. When dry, the edges of the split roll outwards and upwards (in relation to the vertical lamellae when in situ). The split can also be seen in a cross section of the lamella.

Among agarics, this state is only shown by Split Gill, Schizophyllum commune.