The large (250–300 μm) shell has an ellipsoidal shape. A single (?) spiral with closely spaced whorls surrounds a central spongy mass. Medium-sized pores with frames perforate the outer wall. The beams, particularly in the inner half of the shell are not so well aligned between whorls, so the characteristic white stripes of L. h. ‘hayesi’ are only developed in the outer part of the shell in L. h. ‘irregularis’. A wide pylome with teeth is obvious in most specimens. Transitional specimens to L. h. ‘haysei’ are very common.

Remarks. L. h. ‘hayesi’ has so far been illustrated only from the Antarctic, where it is best developed in the Early to Middle Miocene. L. h. ‘irregularis’, by contrast, seems to be relatively cosmopolitan in Mid-Cenozoic sediments, at least in high latitude regions. Specimens of L. h. ‘hayesi’ may, if the centre part of the shell is not fully cleaned of sediment, appear spongy and thus much like L. h. ‘irregularis’.