Spokeswoman Kathy Arberg says the officers who saw the creature Sunday were not sure of its color, and people who saw it on tape had trouble estimating its size. But, Arberg says, those who saw it all agreed that it was, unquestionably, a fox.

The justices went ahead with the oral arguments that had been scheduled in their crimson-velvet-draped courtroom. But by Monday afternoon, it was clear that the fox had become the latest story line in an already strange term at the court. During the recent anthrax scare, the justices were forced to meet outside of their building for the first time since it opened in 1935 because traces of anthrax were discovered in a basement mailroom.