Barbara Bowers had been going to the Club Nautilus of White Flint since January 1981 and just last month renewed her membership. But when she showed up Monday for her regular workout, she found the club empty and a sign announcing that it was closed.

Bowers, who had just renewed her yearly membership Nov. 20, said, "I just feel so violated, so angry."

The spa at the White Flint shopping center was the latest of a growing number of local health spas to suddenly close and leave its paid subscribers out in the cold.

The local club, owned by Lona Corp. of Philadelphia, "couldn't pay the rent," said Bill Scott, director of leasing of Lerner Corp., owner of the Bethesda shopping mall. He said the club had been open "three or four years" and had a history of not meeting rent payments which "we had worked out in the past."

The sign posted on the spa door referred "our valued members" to call the Montgomery County consumer affairs office. According to Peter Berns, assistant Maryland attorney general for consumer protection, several hundred persons also have called his office seeking to file complaints against the club under a new state law that requires health spas to post a $50,000 bond. Club members are entitled to refunds for unused memberships from the bond.

"We don't know if $50,000 will cover" all the Club Nautilus claims, he said. If the amount of the bond cannot provide total compensation to all concerned, Berns said all eligible members will receive a proportion of the money due them.

Representatives of Lona Corp. could not be reached for comment this week. The company also operated about seven clubs in Philadelphia that closed about two months ago, said John Kelly of the Philadelphia regional office of the Pennsylvania bureau of consumer protection. White Flint was Lona's only Washington area club, he said.

The club was operating as recently as Friday and Saturday when investigators with the county consumer affairs office visited the club to make sure membership contracts were not being offered.

Susan Cohen of the consumer affairs office said an investigator was told by a club official on Friday that there was a "freeze on memberships since there were a lot of new sign-ups last week and we couldn't take anymore."