BARRINGTON J. BAYLEY'S work is an example of what is sometimes called "pure" science fiction, the sort of story that makes one gape in astonishment at the strangeness of the idea presented. Bayley is extremely inventive; his well-known story "Me and My Antronoscope" is about a universe of solid rock which had only pockets of space.

Baylor's record collection, The Seed of Evil (Allison & Busby, $4.95, distributed by Schocken Books, shows both his strengths and flaws. His prose can be clumsy, and he is less than convincing when he attempts to describe a future society; there are few women in his fictional worlds, and lumps of exposition often slow the stories down. He is at his best when he concentrates on his provocative ideas and writes in the first-person, with the idea and the necessarily obsessive person involved with it in the foreground. Bayley's view is bleak; one cannot read his work without feeling that human beings are unimportant and the universe uncaring.

The best stories in the collection are "The Radius Riders," about a subterranean ship traveling through the earth; "The Ship That Sailed the Ocean of Space," in which two seedy fellows find a spaceship which is "void of space"; "Fatewell, Dear Brother," a tale of a planet with no chenical or molecular activity; and "Man In Transit," about a man without a passport (a character who could have wandered in from a V.S. Naipaul novel) who has lived his entire life on airplanes. Readers with a taste for cosmological speculation will appreciate this book.

John Brunner is a skilled and versatile writer who is never less than competent and who, at his peak, ranks with the best. Along with other intelligent, craftsmanlike and entremely prolific writers, he is sometimes underrated; yet his early science fiction adventure novels offer suspenseful plots and interesting speculations, while the novels Stand on Zanzibor and The Jagged Orbit remain among the best work of the late '60s and early '70s. Foreign Constelltions (Everest House, $8.95), which means each story is elegantly told, well-plotted and holds the reader's interest, although none is truly outstanding. "Pond Water" is a fable about absolute power; "The Easy Way Out" concerns two survivors of spaceship crash who must either struggle to live or use a device that can make their last hours pleasurable; "The Suicide of Man" is an eerie tale about a suicide who finds himself resurrected in a seemingly utopian future world. Foreign Constellations is a solid and enjoyable collection, even through Brunner's gifts are, I think, better shown in novels, where he has more space to display them.

Norman Spinrad has written short story gems, as a look through his recent collection, The Star-Spangled Future (Ace, $2.25), will demonstrate. If Spinrad has a distinctive theme, it is power; his characters struggle for it or try to figure out how to use it. His latest novel, Songs From the Stars (Simon and Schuster, $11.95) takes place a few centuries after an atomic war; the two main characters, Clear Blue Lou and Sunshine Sue, are on the verge of a discovery which could radically change their society. Spinrad takes these familiar science-fictional elements and creates an original and entertaining story, his best novel so far.

Lou and Sue live in Aquaria, a land on the west coast of the former United States. Aquaria has rejected the "black sciences" of advanced technology, living by the law of "muscle, sun, wind and water," but rqdioactive power cores have been found in several radios used by the Sunshine Tribe's Word of Mouth network. Lou, a Perfect Master of the Clear Blue Way (who functions much like a circuit-riding judge), must travel to the town of La Mirage to confront Sue, heard of the Sunshine Tribe. Sue, however, has a secret ambition. Having learned of the ancient art of "media" from old writings, she dreams of a worldwide communications network. The two do not realize that they are pawns in the plan of a "sorcerer," Arnold Harker, who wants to send a spacecraft to an abandoned space station.

To tell any more would spoil the story. The book is written in a trendy patois which could have been annoying except that it is so perfect for depicting these characters. There is a message in the novel, but it never gets in the way of the story. Spinard is best a detailing the society of Aquaria and its customs, less convincing when he adopts a second-person, present-tense style to convey an alien and transcendent vision, and his descriptive passages can veer toward the purple. But Songs From the Stars is, as a whole, a lively, humorous, lusty, well-plotted, and often poetic book.

Suzette Haden Elgin's Communipath Worlds (Pocket Books, $2.75) includes three previously published short novels -- The Communipaths, Furthest, and At the Seventh Level; each one is a colorful, entertaining space adventure with some depth. Coyote Jones, an operative of the Tri-Galactic Service that patrols a diverse interstellar civilization, is the hero of each story, and he is a genial, thoughful man of action who is gentler and more appealing than most space opera heroes. The female characters include Coyote's strongwilled colleague Tzania Kai, Bess of the planet Furthest (an apthy-named place separated from other worlds by both distance and its secretive culture), and the Poet Jacinth of Abba, a world where women have traditionally been so despised and mistreated that the vaguely Arabic social structure its people has adopted represents an improvement. The author's background in linguistics, her obvious love of her characters, and her attention to the details of her worlds make Communipath Worlds more than routine adventure.

Paul Hazel's first novel, Yearwood (Atlantic-little, Brown, $10.95), is billed as the first book of a trilogy in "the tradition of J. R. R. Tolkien and C. S. Lewis." In a way, this does a disservice to Hazel, who turns out to be an immensely gifted and original writer who doesn't have to be compared to anyone. I knew I was in good hands when I read the opening paragraph of this moving, atmospheric book; Hazel's prose is space, direct, and precise.

Yearwood, though part of a trilogy, is completely satisfying by itself while making the reader look forward to the next volume, Undersea. It is based on Celtic mythology; its hero, Finn, leaves home to look for his father when his mother will not reveal who sired him. Yearwood is not just another adventure with outre trimmings, or a "domesticated" fantasy with cute characters and supernatural details; it is fantasy in the true sense of the word, a story which conveys the power and dark beauty of the myths that are its source. It reveals the strength of the fantasy tradition, that combination of legends, myths and psychological truths so much a part of us that it still makes its way into science fiction, which is ostensibly about things to come, thus making the distant future yet another mythological realm.