The bivalve fauna from the "Glauconie de Lonzee", a highly fossiliferous glauconitic sand of probable Santonian age, is described for the first lime. Twenty-nine species have been recognised: a cucullaeid, a glycymeridid. two limids, three inoceramids, eight ostreoids, four pectinids, a spondylid. a trigoniid and eight heterodonts.Palaeoecologically the major part of this fauna is interpreted as typical for an argillaceous to sandy environment in an open marine shallow subtidal, inner shelf setting.Palaeobiogeographically the assemblage is nearest to the Lower Campanian fauna from Aachen, to Turonian- Santonian central European faunas on the coasts of the Hercynian massifs in Saxony and Bohemia and to the Middle Santonian Subhercynian Cretaceous Basin in Sachsen-Anhalt. The faunal composition indicates strong connections with central and eastern Europe. It does not confirm a direct relation with the Paris basin as was previously suggested.