Is a small family of large elongate snails living in Madagascar, formerly placed most often in the ACAVIDAE, but now split from that family once more.
There are 3 genera: the attractive Leucotaenius (7 species), Paraclavator (3 species) and Clavator (13 species, some very rare).
For a list of genera and species:
http://molluscabase.org/aphia.php?p=taxdetails&id=993104
The literature:
2002 Poppe, Groh & Charles
A Conchological Iconography. Family ACAVIDAE, excluding Ampelita.
2014 Cossignani Tiziano
African Landshells.