Two new U.S. stamps, the second issues in the annual America Series, have "Natural Wonders" as their theme.

With these issues, the U.S. Postal Service joins 23 other postal administrations, all members of the Postal Union of the Americas and Spain (PUAS), in issuing stamps with the Natural Wonders theme.Each PUAS member has planned its designs in a continuing series leading up to the 500th anniversary of Columbus' arrival in the New World. The series is designed to familiarize the people of the member nations with one another.

The U.S. stamps are a 25-cent commemorative and a 45-cent airmail. The commemorative features an artistic rendering of the Grand Canyon as it may have appeared to the Coronado expedition, believed to have been the first European explorers to see it. The airmail shows the natural surroundings of an American Caribbean tropical isle coastline much like the shores of the outer islands first seen by Columbus on his arrival to the New World.

First-day cancellations are available in the usual two methods. The deadline for ordering is Nov. 11.

The Postal Service gives preferential service to those customers who buy the stamps at a local post office, affix them to a self-addressed envelope and mail it for cancellation to: Customer-Affixed Envelopes, America Series Stamps, Postmaster, 100 Mather Business Center, Grand Canyon, AZ 86023-9991.

If you prefer to have the Postal Service affix the stamps, send, for each cover desired, a self-addressed envelope and payment in check or money order for the appropriate amount - 25 cents for the commemorative, 45 cents for the airmail or 70 cents for both - to: America Series Stamps, Postmaster, 100 Mather Business Center, Grand Canyon, Ariz. 86023-9992.A tribute to the centennial of the founding of the Daughters of the American Revolution (DAR) is seen on a new EXTRAordinary View Card. The design features Memorial Continental Hall and Constitution Hall, both of which are Registered National Historic Landmarks and part of the DAR National Headquarters in Washington, D.C.

A glossy reproduction of Memorial Continental Hall appears on one side of the card. A color reproduction of Constitution Hall is on the reverse side, where there is also space for a personal message and the mailing address. The card costs 50 cents, which includes the 15-cent postage.

First-day cancellations are available. The deadline for ordering is Nov. 10.

The Postal Service gives preferential service to customers who buy the card at a local post office, self-address it and submit it for cancellation. Mail the card to: Customer-Supplied Cards, Constitution Hall-Memorial Continental Hall Postal Card, Postmaster, 900 Brentwood Rd. NE, Washington DC 20066-9991.

If you would rather have the Postal Service supply the card, send, for each card ordered, payment of 50 cents in the form of a check or money order and a peelable, self-addressed label, to: Constitution Hall-Memorial Continetal Hall Postal Card, Postmaster, 900 Brentwood Rd. NE, Washington, D.C. 20066-9992.Sir Winston Churchill and World War II are the subjects of two new sets of stamps issued by the Isle of Man.

There are four stamps in the Churchill set. The 19-pence shows Churchill receiving a trophy as Freeman of the Town of Douglas in 1957. The 32-pence depicts him in his familiar derby. The 34-pence portrays him with a night view of London during the Battle of Britain. The 37-pence illustrates him in naval attire.

The Battle of Britain set is dedicated to the 50th anniversary of the air triumph of the RAF over the Luftwaffe that saved the British Isles from invasion. There are three setenant (attached) stamps that pay tribute to the different service and civilian units involved in the conflict.

The Isle of Man Post Office also is issuing a special folder containing the three sheetlets of the Battle of Britain commemoratives plus an outline of the importance of the events in 1940.