THERE'S A TRADITION in English fiction that offers such pleasures as Jane Austen and Nancy Mitford. Trollope's Barsetshire and Mrs. Gaskell's Cranford are two places where its docfrines hold sway, and its populace includes, E. M. Delafield's "Provincial Lady," E. F. Benson's Lucia, Elizabeth Bowen's early heroines, all of Angela Thirkell's characters, and Carroll's Alice, not to mention the White Rabbit. Whether comedy or satire, sharp or gentle, what it has to do with is behaving properly: not just propriety, mind you, but knowing when to be early and when to be late, how thin to cut the bread, which cocktails are vulgar, and, most of all, knowing when to lift an eyebrow to achieve the maximum effect.

The late Barbara Pym practiced in this tradition, producing seven novels between the years 1950 and 1961 before dropping from sight until 1977. It was then that two persons polled in a Times Literary Supplement survey put her works on their lists of the century's most underrated. Pym, by that time retired to a cottage in Oxfordshire, her books out of print, suddenly found herself rediscovered, to her "delighted surprise." Having once said to a friend, during the years when her audience appeared to have deserted her, "I'm afraid my kind of thing is now out of date," she responded to her born-again literary fame by starting to write once more.

Two earlier novels were reissued and she completed Quartet in Autumn, (Perennial Library/Harper & Row, $2.50) which was published in 1977. Next came The Sweet Dove Died, (Perennial Library/Harper & Row, $2.50) now followed by A Few Green Leaves, which Pym finished shortly before her death last winter. Each of these books has been welcomed by the critics and by a growing number of aficionados; though no claims have been made that Pym is a major writer or of the first rank, neither has there been any dispute that she brought an extremely perceptive eye and a graceful touch to the ironic comedy of manners.

Anyone who was introduced to Barbara Pym through the pair of books from the '50s -- Excellent Women (Perennial Library/Harper & Row, $2.50) and A Glass of Blessings (Dutton, $10.95) -- that were republished in the late '70s must have been taken aback by the tone of Quartet in Autumn. Where the former two were teasingly appreciative of all luxury great and small, the latter novel struck an unexpectedly downbeat note. It was as if the 16-year hiatus had robbed Pym of some special quality of mischievous zest. Naturally, anything could have occurred over such a long period, the least of which we know would have been Pym's own aging and her retirement from her job. But it is rarely that we see such change without the intermediate stages.

Both Excellent Women and A Glass of Blessings featured heroines whom Pym mocked fondly. In the former, Mildred Lathbury, who belongs to the ranks of "excellent women," identified herself as one from whom platitudes easily flow; a clergyman's daughter, who leads an orderly life and, without even meaning to, lands an equally excellent, if slightly more eccentric, man. A Glass of Blessings is, amazingly, on the surface just that: Wilmet Forsyth seems to have everything, including an elegant wardrobe, lots of free time and money, a charming house and an agreeable mother-in-law. Things are a bit shaken up at the end, but not much more than that.

In Quartet in Autumn, however, the title once again gives the clue. It depicts the mostly empty lives of four elderly office workers, two of whom are retiring. Each viewed separately seems pathetic; even regarded together, in the odd relationships born of propinquity, they are not very appealing. Moreover, in contrast to the opulence of Wilmet's life and even to the prim tidiness of Mildred's, Quartet in Autumn deals with the state of deprivation, which implies "once having had something to be deprived of." Might not, one of the characters wonders, "the experience of 'not having' be regarded as something with its own validity?" Yet the close of the book points the way to The Sweet Dove Died which gives us the comically selfish figure of Leonora Eyre.

Leonora, surrounded by possessions, still courted by admirers young and old, is arriving at old age with a queenly air of disregard. Her life is indeed her art, and if she's like one of those ornate china shepherdesses -- hollow inside -- well then, she is still taking up where dowdy Letty of Quartet in autumn left off. Both women are survivors, but it is Leonora who acts on what Letty realizes, that life always holds "infinite possibilities for change."

Emma Howick, heroine of A Few Green Leaves, is the first one of the major Pym female characters to be an intellectual, though some of the secondary ones -- notably, Mildred Lathbury's neighbor, Helena Napier, and Wilmet Forsyth's mother-in-law -- in previous books have had careers in anthropology or archaeology, indicating their more rigorous turn of mind. Up until Emma, Pym's central women have each emphasized their own lack of seriousness. (Pym herself worked at the International African Institute as editorial secretary and assistant editor of their journal.) Unlike Wilmet or Letty, Emma lives on a simple scale; less demanding than they, she is staying temporarily in her mother's cottage in a small village while she types up some fieldwork. Neither is Emma very womanly, or, that is to say, like Mildred and Letty, she is not romance oriented, although she does on impulse summon up an old suitor, a fellow scholar whom she notices on a television talk show.

But somehow Emma is an amalgam of all of Pym's heroines, the place at which they all meet. Not as sleek as Wilmet, she is not as depressing as Quartet's Marcia, either. Self-absorbed, but without Leonora's solipsism, Emma is what she should be; sensible, acutely observant, wryly self-aware with yet a few blind spots, humorous, open to experience, lacking in guile. Unfortunately, Emma hasn't a very high opinion of herself, and this reminds us of Mildred Lathbury, which in turn reminds us that Mildred actually had more charm than she gave herself credit for. One of Pym's talents, it seems, is for revealing her characters on two levels -- how they see themselves and how they are seen by others.

A Few Green Leaves is described by Pym in her dedication as "this story of an imaginary village." To those of us who have visited such communities, in our imagination if not in fact, all of the institutions are familiar: the rectory, the surgery, the dislapidated abode of the local cat-lady, the manor house and the pub. Pym does nothing dazzling with these ingredients, but, as always, the story stays afloat, as on a wave of tea, carefully brewed. Sometimes a nanny kind of voice creeps in, and there are those recognizable, somehow comforting, Pym words, like "dreary," "cross," "dim" and "suitable." There are even references to characters from the earlier books, including one to the indespensable secretary of a learned society who has shirked her duty and died.

There are personages with names like Miss Grundy and Miss Lickerisk, and there is a fine example of Pym's enjoyment of a good list: "chipped cups and old saucers suitable for cat dishes, plastic earrings, an old string of pearls with the pearliness peeling off, a tattered paperback novel whose cover portrayed the bare shoulders of a couple in bed, a bundle of knitting needles, a plastic butter-dish with a split at one corner, an old prayer-book with no cover and pages missing, a rusty nutmeg grater. . . ."

One could wish that the late Pym had more of the sparkle of the first books, but one imagines at the same time Pym's answer to that -- "a small useless longing" she would call it. There appear to be four vintage Pyms not yet reissued; until they are published, we will have to be satisfied with what we have and take as Pym's farewell this set of "anthropological" vignettes of British exurban life, at once so cosy and so bleak.