Atheist Madalyn Murray O'Hair announced yesterday she has asked the federal court here to bar Pope John Paul II from saying mass on the Mall Oct. 7 during his visit to the United States.

At a press conference at the American Atheist Center in Austin, Tex., O'Hair said she mailed copies of the lawsuit to the U.S. District Court here last week, contending the mass would violate the consitutional principle of separation of church and state. The suit lists the Interior Department and National Park Serivce, which have jurisdiction over the Mall, as defendants.

A court check late yesterday indicated the suit has not been filled here yet.

O'Hair said she had also mailed a lawsuit to U.S. District Court in Boston, naming the pope as a defendant and asking the court to stop him from saying the mass. She said the suit would be served on the pope by U.S. marshals when he arrives in the United States on Oct. 1 for his seven-day visit.

Paul Funderburk, an Austin attorney, associated with the atheist group said in a telephone interview that O'Hair and her son, Jon Garth Murray, are filing the lawsuits without legal counsel and plan to represent themselves if the matter comes to a hearing.

O'Hair achieved prominence in 1963 when she was the plaintiff in the landmark case in which the Supreme Court banned official prayers in public schools.