This celebrated French house — known for striped knits and its nonpareil grasp on insouciant Left Bank style — put itself in a rough-and-tumble place for fall: the schoolyard. Artistic director Nathalie Rykiel laid out a soot black set of cobblestone, a chain-link fence, a garbage can, branches of fluorescent tubing and a blanket of smoke. Then she armed her troupe of bad-girl models with picnic-blanket plaids, neon-colored fox stoles, quilted warm-up jackets, skin-tight stirrup pants and patent stilettos. Suddenly, a house known for perky Parisians yielded to teenage riot. The first look, a roomy wool car coat lashed with fur sleeves over a flesh-toned sweater and red pencil skirt, was promising: a punchier new take on the saucy femininity from the house that Sonia built. But then came the pileups of checks and tartans, giant bow sweaters, fluted Forties skirts and metallic leather strips slapped on jersey. There were whiffs of the Rykiel vocabulary — touches of quilted satin, rhinestone embellishments and lingerie elements — but they got lost in the heavy-handed styling and the offbeat color combos. Charm school this was not.