They were laughing, but in a sort of astonished way, as if fulfilling the requirement that good guests laugh at the speaker's jokes.

"This is a bachelor's paradise," Sen. Strom Thurmond (R-S.C.) had just told the crowd of women lawyers and judges.

"I want to congratulate you lady judges," he said. "You really don't look like judges, you look like young ladies."

A few laughs, good guests to the last, but it was getting quieter.

"We're very proud of the job you're doing," Thurmond was saying. "Anything we can do for you on the Judiciary Committee -- it'll be a pleasure."

One woman shook her head.

"I just want to know what a lady judge looks like," she whispered to the lady judge next to her.

The women listening to Thurmond yesterday were members of the National Association of Women Judges, local women's bar associations, the National Association of Black Women Attorneys and the National Bar Association Women's Division. Everyone, it seemed, was "the honorable . . ."

They were attempting to salute the women of the 99th Congress, in the Capitol's Mansfield Room, but what with the MX vote, which kept the House in session well into the hors d'oeuvre hour, the salute was rather abbreviated. Only a few legislators appeared, and most of those who did raced off before they even collected their name tags.

But this was only a reception. The real work was going on elsewhere.

"The last figures I saw indicated that the Reagan administration had appointed fewer than 20 women to the federal bench," said National Association of Women Judges president Martha Craig Daughtrey. "Quite frankly, we were distressed by that showing. The Carter administration appointed 40 women in that length of time."

Daughtrey, a Court of Criminal Appeals judge in Tennessee, had spent the day trying to do something about the numbers. She met with White House counselor Fred Fielding and Justice Department officials.

"I told those gentlemen, somewhat jokingly, we would like to have the next 50 seats if we could," Daughtrey said. "I got the sense that Mr. Fielding would like there to be more women appointed."

And then she laughed and said, "The one thing I am determined to be on this trip is positive."

Marguerite Rawalt, who was one of only a few women to graduate from the George Washington Law School in 1933, can be positive, too.

"This is just wonderful, to see all the progress that's been made," Rawalt said, waving her hand to take in the room. But she has also kept track of federal appointments of women judges.

"President Carter really opened the gates," she said. "Now we have a president who appointed one woman, thank God, to the high court, but we're trying for more all the way through the ranks."

Gladys Kessler, a D.C. Superior Court judge, said, "On the state level, we are seeing women appointed. On the federal level, we are certainly seeing a decline in the percentage of women appointed."

Thurmond, who was making his way to the door via several score handshakes and shoulder pats, didn't agree.

"I think he's appointing more and more," Thurmond said of Reagan's record.

"I think he's been doing fine!" interjected a smiling woman as she approached Thurmond, her hand out.

Thurmond nodded.

"He's a good man," he said, squeezed the hand and left.