Fairfax County officials angrily demanded yesterdaythat D.C. Mayor Marion Barry apologize for what the Northern Virginians said was a joke about County Board Chairman John F. Herrity's recent heart attack.

The mayor said at a press conference Wednesday that he had told Herrity at a meeting the day he suffered his third heart attack that the District would not close its Lorton prison in Fairfax. "Unfortunately, that news had some kind of effect on him," Barry said.

"It's a low blow from the gutter," said Martha V. Pennino, vice chairman of the Board of Supervisors. "If he meant it seriously, then an apology just has to come," said Supervisor T. Farrell Egge, whose district includes the District-run prison. "I do think Mayor Barry went a little far," said Supervisor Audrey Moore of Annandale.

Annette Samuels, the mayor's press secretary, said Barry "wasn't quipping. He didn't make light of it. I have not talked to him, but being present at the meeting, I know he did not make light of it."

Herrity, 53, was reported in good condition yesterday at Fairfax Hospital, where he is scheduled to undergo further tests today. His spokesman, Bob Foreman, said that Herrity hadn't heard of the Barry remark.

Foreman said he believed the mayor should apologize "to clear the air. We haven't had any apology that would indicate to us it was [said] in a joking manner."