First, it was a large lion that was reported running loose yesterday morning behind a string of stately mansions in the Embassy Row stretch of Massachusetts Avenue NW. A short while later the animal was spotted again, but was reported to be a bit smaller.

"I saw it," said D.C. police officer Leonard G. Gooch, from whom the cat had retreated into the woods. "It's about half the size of a full-grown lion."

An impromptu safari was soon launched by about 50 law-enforcement officers, some ready with rifles. But by midafternoon, the beast -- spotted at least two more times -- had been determined to be a two-foot-long cougar or bobcat, at best.

Finally, the search team, led by National Zoo veterinarians armed with tranquilizer guns and a large hoop net, flushed out of the woods what looked like a small fox. The searchers last saw whatever it was fleeing across Massachusetts Avenue near the grounds of the Naval Observatory, which include Vice President George Bush's official residence.

With no cat in sight and no apparent danger in the offing, the searchers went home.

"I'm not sure what we were looking for," said Andrew Teare, a veterinarian at the National Zoological Park who had trod through the peaceful woodlands in search of the purported lion. "As I understand it, the first officer thought it was five feet long. The second thought it was much smaller. What we flushed out was probably just a fox. It was fox-sized and grayish colored."

The animal originally seen "could be a wild bobcat," Teare said. "It could easily have worked its way this far east from Shenandoah, perhaps."

Zoo officials said none of their animals were missing. Police said no one has called to report the escape of an exotic pet. "We don't know where it came from," a D.C. police spokesman said.

Yesterday's search, albeit fruitless, offered brief comic relief to Washington's summer doldrums: While a police helicopter hovered, story-hungry media foot soldiers--armed with notebooks, cameras and walkie-talkies -- camped out at the driveway of the abandoned Iranian Embassy, waiting for news of the lion hunt.

Lewis Regenstein, vice president of the Washington office of The Fund for Animals, a preservation society, happened to bike past the Embassy Row hunting grounds. He approached the situation with informed seriousness: "It'd be a real shame if it got shot or hurt," he said. Rock Creek Park "draws all kinds of wild animals that you never hear about."

There are many wooded routes that lead into the park from the Maryland suburbs, he said, recalling that two months ago police killed a wild black bear that was found roaming through a Bethesda neighborhood.

Told that the animal had apparently escaped, Regenstein could breathe easier. "Well," he said, "that's another victory for wildlife."