To the casual onlooker, it might seem as though C-SPAN, the congressional cable TV channel, is trying out a National Geographic-type set.

How else could one explain a congressional hearing that will include:- An appearance by a 2-month-old bat, known as the Samoan flying fox, named Pe'a Vao.

- Testimony from the governor of American Samoa as well as two high-talking Samoan tribal chiefs with the ceremonial costumes.

- And discussion about a South Pacific rain forest.

But politicians and bureaucrats in the nation's capital will be treated to the Polynesian flavor for a purpose. Thursday's hearing by the House Subcommittee on National Parks is to review HB4818 - a proposal to create a national park in American Samoa as part of rain forest-conservation efforts.

"About the only thing we'll be lacking is a roast pig with a hibiscus in its mouth," said Dr. Paul Cox, associate professor of botany and range sciences at Brigham Young University. With a decade of professional studies of Samoan rain forests, Cox will also be testifying during Thursday's hearing.

HB4818 was introduced earlier this summer, while a similar bill was sponsored in the Senate only last week. With admittedly guarded optimism, Cox is hopeful that the national park status will be approved by late this year.

The proposed national park area is some 11,000 acres of lowland rain forest on two islands - one on the largest island of Tutila and another on Ta'u. The area features contiguous rain forests and coral reefs, which Cox labels as the two most complex ecological communities located side by side.

With the forests offering no valuable minerals or oil deposits, the proposal for the rugged area lacks controversy or competition from outside interests or developers. "It seems like a win-win situation," said Cox, explaining that Samoa retains a protected rain forest while the United States benefits from a unique national park - the only real rain forest on American-controlled soil.

Some 25 percent of the plants found in the rain forest area are indigenous to Samoa, with the proposed area possessing no thorns or dangerous animals. "It's like Eden," Cox said.

In the independent nation of Western Samoa, rain forests are falling victim to corporations from Japan and other foreign countries, Cox said. The timber is then used for wood pulp and refined products such as tissue and toilet paper.

Cox likens the situation to blowing one's nose on a Michelangelo painting. "It's a crazy way to use a priceless resource - to blow your nose on it."

Rain forests in American Samoa are not under the same relentless pressures but still are threatened by continued progress and development. The danger is somewhat slower by comparison with Western Samoa but nonetheless encroaching.