Shante Tolson said she liked the orange-legged puppet in the slinky pink dress who boogied to a disco beat, but the dinosaur act -- featuring a rock-singing hadrosaur from Hackensack, "the Bruce Springsteen of dinosaurs" -- seemed to be the favorite of many of the 9,000 schoolchildren who visited Wolf Trap by the busload last week. They were taking part in Wolf Trap's fifth annual Chapter I festival, a special arts program for youngsters from low income areas.

Each of the more than 40 Maryland and Virginia elementary schools that attended this year's festival receives funds from Chapter I, a federal program for educationally disadvantaged children that began 20 years ago under President Johnson's Great Society policy. (District schools, almost all of which receive Chapter I money, could not attend last week because of lack of funds for bus transportation, said Anne Titts, Chapter I director for the D.C. public school system.)

According to Mary McEachern, a Chapter I specialist with the Montgomery County schools, the program makes its biggest mark by providing instructional assistants in classrooms to work closely with children who are weak in reading, language or mathematics skills. Chapter I also exposes children to the arts through twice-yearly visits from flamenco dancers, folk singers, musicians expert in early American instruments and the like. And through sponsorship by Cabinet spouses, third-graders from Chapter I schools in Maryland and the District attend a concert of the National Symphony Orchestra each year.

But Wolf Trap's Chapter I festival is special. "The festival gives kids a chance to participate in the nation's performing arts center, a chance they might not usually have," McEachern said. "Many of these children come from families with no car, or with a single parent or two working parents who do not have the time or money to come to Wolf Trap." According to Mary Brown, the Wolf Trap cultural affairs specialist who helped found the festival four years ago, the schools provide buses and lunch, and this year the National Park Service paid for the rest (about $5,000). "For many schools," said McEachern, "this is the big field trip of the year."

The yellow school buses began arriving just after 10 last Monday morning, full of youngsters from Prince George's, Montgomery and Fairfax counties who streamed onto the grassy field where Michele Valeri and Mike Stein, "the Dinosaur Lady and Dr. Jones, the paleontologist," threw out facts about the prehistoric creatures (researched by the Smithsonian) during patter songs from their album "Dinosaur Rock." The children, mostly ages 4 through 9, swayed through the dinosaur dance and laughed as Stein donned a giant, froglike mask with silver sunglasses to become the first rock-singing hadrosaur, a swimming dinosaur, from the Garden State. Then there was Stella Stegosauros and a ditty about a pterodactyl, a flying reptile, aptly titled "Leapin' Lizards."

"I liked Stella," said Angela Stuart of Fields Row elementary school in Gaithersburg as she moved on to another event. "I did a report on Stella -- she's got a long tail and a brain the size of a walnut." A boy named Edmund looked serious and said, "I've seen dinosaurs -- live, four or five of them, in Texas."

Down a dirt path scented by honeysuckle and in the shadow of the Filene Center, children sitting on long wooden benches cheered Bob Brown's menagerie of marionettes: bashful Gus; a pink-nosed Emmet Kelley-esque clown who inflates balloons thanks to a can of compressed air in his stomach; Sing and Ling, pigtailed Chinese acrobats with bouncing bodies made of Slinkies; and Walter and his horse Whoople, who can't seem to get together.

"My friend liked Lionel a juggling lion because they have the same name," Clifton Hardy of Twinbrook Elementary School in Rockville later confided, pointing to classmate and fellow 7-year-old Lionel Young.

In an open stage shell down the road, Tom Casciero, a mime-actor and storyteller, pulled props from a galvanized garbage can, extracted a rubber chicken ("his name is Jody. We go back a long way, since he was an egg") from a dilapidated guitar case, and played with der-ders.

Der-ders? "They're the cardboard tubes your mother would give you when all the paper towels were gone," Casciero explained. "The first thing you'd do is make that sound, der-der-der, like a trumpet." In his act, Casciero used all sizes of tubes to make not only trumpets but fishing rods, telescopes, stick shifts and golf clubs.

"I get my ideas from my childhood and from watching kids," he said. "Kids can become intensely interested in something -- they drift right into an activity and are absolutely focused by it. I want to project that on stage . . . I also want to show kids, through the process of having things laid out like a jungle gym, that an adult can engage in childlike behavior. I'm saying to them, when you get to be an adult, you don't have to lose that."

In addition to the Chapter I Festival, Wolf Trap sponsors a children's theater program on weekdays during the summer, beginning June 24. The program is free for all children, and this year will include morning performances of African Heritage Dancers, P.G. Opera's "Hansel and Gretel," folk singers and Library Theater, which dramatizes books. On six Saturday mornings at 11 a.m. in July and August, two of Offenbach's comic operas will be performed. (For more information and reservations, call 703 255-1827.)