STAND IN A BOOKSTORE, near a display of horror fiction, and you're very likely to hear readers exercising the single most compelling literary criterion for the genre. "Is it scary?" they want to know. There are other, and perhaps more dignified, standards to be applied, but "Is it scary?" is the bottom line.

Ramsey Campbell's stories are scary. He has been writing them, and building his reputation on them--the highly-praised fantasy magazine Whispers has just devoted a special issue to his work--for 20 years now, and his latest collection, Dark Companions, is both more accessible and more frightening than the earlier volumes. His recent novels, The Parasite and The Nameless, were well-received both here and in England, but Campbell seems most comfortable with the short story, where form and content conspire to create the effect on which horror fiction, blatantly and passionately, depends.

Campbell's people are as real as you or me, his settings--most often urban, gritty, and unwholesome--as immediate as the street outside your window, and the horrors as implacable as death. At his best, as he is in many of these stories, three of which are prize-winners, he can make something as familiar and reassuring as your kitchen table look positively deadly.

His characters move among "cracked and overgrown streets, past rusty cars laid open for surgery, old men propped on front steps to wither in the sun, prams left outside houses as though in the hope that a thief might adopt the baby." A carton of books in the back seat of a car smells "more dusty than the streets." In Campbell's relentlessly grim world, things are no better indoors. One character "had never realized how many dark corners the house contained. Many of them had begun to acquire objects, some of which moved, none of which was there when she strode close." His world, so realistic and contemporary in its details, quivers with the force of half-recognized and ancient childhood menaces, the suddenly familiar and frightening things that we knew all along were lurking there.

In "Calling Card" (a Christmas ghost story comissioned by a British newspaper which then refused to publish it), a middle-aged woman faces the embodiment of all her unexpressed fears of loneliness. An unsigned greeting card wishes her "A Very Harried Christmas," and something unspeakably horrible--Campbell, though clear, is reticent about his monsters, leaving our imaginations to do their worst--comes crawling across her doorstep to welcome in the new year. In "The Companion," an equally lonely man finds only greater darkness when he seeks to hide from himself. In Campbell's very modern world, things are bad to begin with . . . and then they get worse.

There have always been monsters, whether hiding in the forest or lurking in our minds, and A Treasury of Victorian Ghost Stories, edited by Everett F. Bleiler, offers a generous sample of stories that frightened another age. Bleiler is our leading authority on Victorian popular literature and has edited collections of Ambrose Bierce and J. Sheridan Le Fanu, among others, as well as several excellent anthologies. He is expert at finding little- known pieces and, while his introductions are satisfyingly scholarly, he presents without apology stories that often found more favor with the public than they did with the critics of their time.

The present volume offers ghost stories by Bierce, Le Fanu, Charles Dickens, Wilkie Collins, Gertrude Atherton, and Arthur Quiller-Couch, as well as work by names that have faded somewhat since their heyday: Mr. J. H. Riddell, Mrs. Margaret Oliphant, Rhoda Broughton, and Emma Dawson, among others. The book will be a joy to the connoisseur, offering stories unavailable elsewhere, but the casual reader may wish for some of the better stories of the period and will have to adjust his taste and expectations to those of an age that could shudder at rather understated curiosities. ("A very odd thing happened to my uncle," is the innocent beginning of a story here by Le Fanu.) But, allowing for differences in style and taste and structure, there are nightmares of the mind here too, and many of the stories are indeed scary. The prize of the collection is "Ken's Mystery" by Nathaniel Hawthorne's son, Julian, which has the pace, the imagery, the strangeness, the awareness of ancient and inexplicable evils, the growing chill and sense of dread, that would make it fit comfortably into any contemporary anthology.