A misericord is a minor bit of ecclesiastical fakery: a small ledge on the underside of a hinged church seat, on which a ""standing"" worshiper may unobtrusively sit with the seat folded up. Beneath the misericord, medieval ingenuity discovered the ideal site for carved jeux d'esprit--caricatured faces, cavorting animals, scenes of burgher or peasant life--some quite bawdy--and illustrations of proverbs. Most of the Kraus' handsome black-and-white pictorials are from 15th and 16th century France.