Mr. Barnes’s latest collection, “Pulse,” is filled with both gems and should-have-been discards. The title story and “Marriage Lines” are beautiful, elegiac tales about how marriages endure or change over time: stories that attest to the new emotional depth Mr. Barnes discovered in his 2004 collection “The Lemon Table.” Unfortunately, many other entries in this volume are brittle exercises in craft: a writer writing on automatic pilot, substituting verbal facility for genuine humor or real feeling, a scattering of social details for a persuasive sense of time and place.