American Innovations (Farrar, Straus and Giroux, $24), Rivka Galchen’s astonishing debut short-story collection, is smart, slyly funny, and usually at least a bit off-kilter.  In the opening story, “The Lost Order,” a woman answers her phone and, rather than tell the caller that he’s dialed the wrong number, takes the man’s order for Chinese food delivery.  The title story is an homage to Gogol’s “The Nose”; in this version, a woman comes home from abroad to discover that she’s grown a breast on her back.  In “Wild Berry Blue,” a girl having breakfast with her dad at McDonald’s encounters her first love, a heavily tattooed, recovering drug addict working behind the counter.  Galchen’s stories can be strange and mysterious, but it’s difficult to read them without grinning and marveling at her charm, imagination, and command of language.