The shell (about 130–140 μm long) has an asymmet- ric, elliptic shape. In the centre of the shell often a spongy, dark disc can be found, which is surrounded by about three whorls of a single (?) spiral, which are generally irregular in shape. In some specimens the spiral is very weak or absent. A distinct polar cap can be seen in many specimens. The shell surface is rather smooth, due to the irregular-sized pores which lack frames. A wide pylome with teeth is present.

Occurrence. Early Miocene–Mid Miocene.

Remarks. Some specimens are very similar to L. polyacantha, but the shell is smaller and the presence of the spongy disc in the centre is characteristic for L. nebulum.