The familiar illustrations of Washington's Susan Davis are friendly as can be. No smog befouls her colored skies, no sharks lurk in her seas. Lions snarl and roar, hers seem disposed to chat. Her sunbathing fat ladies, bouncy as balloons, but warmed by her affection, do not seem grotesques. Davis never scares us. Even when she paints from life, as she often does, she filters out the fierce.

Her black-and-white ink drawings--they regularly accompany Henry Mitchell's "Any Day" in these very pages--are full of the fantastic. Yesterday, for example, she showed us winged loons in cowboy boots and Stetsons pecking holes in textbooks. She is widely known in Washington for posters, cards and calendars. She does record jackets, too. A recent Davis painting, of a sunset on the Eastern Shore, is scheduled to be reproduced as a New Yorker cover. Successful illustrators must work in varied styles. Davis has a number. Most are represented in her current exhibition at the World Bank's gallery, 701 19th St. NW. It is a large and joyful show.

Many popular cartoons, and Davis flirts with the cartoon, are spiced with gore and pain. A buzz saw cuts a bulldog into bloody pieces, a pussycat is squashed by a three-ton falling safe. Davis is too sweet to find such carnage funny. When she portrays small disasters--say, a flooded basement--they look like small delights. Water from the backed-up drain provides recreation for various smiling frogs and fish and happy diving mice.

Though cuteness tends to pall, the finest pictures here are rescued by their freshness. The artist's use of watercolor is particularly skillful. With a single touch of her dripping brush she can conjure up a breaking wave, the ripply reflections on a goldfish pond, a feather or a flower or haze on rolling hills. Many of her newest works are scenes of Tilghman Island and its picturesque environs, of country stores and sailboats and fall foliage on islands. Though in paintings such as these we recognize the real--the cracked paint of old houses, the burnt grass of high summer, wind moving on the bay--the colors Davis uses look less like those of rural life than those of gentle dreams. Davis does her nicest work when she somehow blends the seen with the imagined. Her 81-item show closes Aug. 27. 'The Cow' at Gallery 10 Ltd.

Few familiar animals are as likable as cows. Dogs may be our closest friends, but they often act like fools. Cats, despite their beauty, frequently succumb to anxiety attacks. Cows are solid citizens, generous and gentle. They give us milk, they moo, they rarely misbehave. No wonder painters love them. The patient landscape painters of 17th-century Holland thought a painting without cows somehow incomplete. The Barbizon School painters of the 19th century were similarly enchanted by the beauties of the bovine. The summer exhibition at Gallery 10 Ltd., 1519 Connecticut Ave. NW., also hymns the cow.

Occasionally it does so with unseemly humor. Cows stare and chew their cuds and graze with admirable decorum, and are thus best portrayed. It is a bit disturbing to see, as one does here, those noble beasts consort with such frivolities as Rubik's Cubes and penguins.

The exhibit, though a group show, is focused on the drawings of Seana Mercedes Mallen, whose picture sequence illustrates "A Field Trip to our Nation's Capital, a Treat for the Whole Herd." Her visitors are Holsteins. They proceed, as tourists tend to do, from the White House to the Lincoln Memorial to the National Gallery of Art. Though baffled, and who isn't, by the Robert Motherwell paintings on view in that museum, they never lose their dignity. They admire the Washington Monument. ("They found it," Mallen notes, "very tall and thin.") They also cross the Mall to pay a visit to the Hirshhorn. ("It hadn't occurred to us there would be no horns at this museum.") Also on display are two cow-sculpted salt licks. They look like Henry Moores. "The Cow" closes Aug. 14.

Sigrid Bruch's Bird Paintings

Sigrid James Bruch, who worked for three years as a resident artist at the National Zoological Park, is showing her bird paintings in the rotunda of the National Museum of Natural History. They are no threat to Audubon's. Bruch has a nice graphic sense. She likes to pose her subjects against bright and uninflected fields of flat color, against oranges and greens and blues rarely found in nature. Seen from far away her pictures jump out from the walls, but close up they go flat. Most good bird painters, and there are many of them, work from skins or living birds. Bruch appears, however, to rely upon the photograph. One feels that she has studied paper prints, not feathers, slides instead of beaks. She summarizes broadly, her details are meager. The feathers of her Harris' Hawk look far less like feathers than they do like pieces of plastic or chain mail. Her birds look less like birds than like passages of paint. Her show closes Aug. 15.