Melissa Mathison, who wrote the screenplay for “E.T. the Extra-Terrestrial,” the science-fiction fable that became one of Hollywood’s signature depictions of the anxieties and longings of childhood and cemented the reputation of Steven Spielberg as a leading director of artful, popular movies, died Wednesday November 4th in Los Angeles. She was 65. Before “E.T.,” which appeared in 1982, Ms. Mathison had written only one feature film, sharing a screenplay credit (with Jeanne Rosenberg and William D. Wittliff) on “The Black Stallion” (1979), an adventure melodrama, based on the novel by Walter Farley, about a boy and the horse whose life he saves. It was a favorite film of Spielberg’s. Ms. Mathison met him in the Tunisian desert on the set of “Raiders of the Lost Ark,” which he was directing, and which starred her boyfriend (later her husband), Harrison Ford. Melissa Marie Mathison was born in Los Angeles on June 3, 1950, to Richard Mathison, a journalist, and the former Margaret Kieffer, known as Pegeen. Ms. Mathison graduated from Providence High School, a Roman Catholic school in Burbank, Calif., and attended the University of California, Los Angeles, and the University of California, Berkeley. Among her first movie jobs were low-level positions on “The Conversation” and “The Godfather Part II,” both directed by Francis Ford Coppola, whom she had met, her brother said, when she was babysitting for friends of his. Ms. Mathison’s marriage to Ford ended in divorce. In addition to her brother Dirk, she leaves another brother, Mark; two sisters, Melinda Johnson and Stephanie Mathison; a son, Malcolm Ford; and a daughter, Georgia Ford.