Prince George's County librarians turned out in force last night at a meeting of the county's Library Board to make an unprecedented show of displeasure at the board's recent decision to increase their work week without more pay.

"I don't think I've ever seen so many of you here before in my six years on the board," said Chairman David Goldsmith, surveying the crowd of more than 100.

The librarians had traveled to the meeting at the Hyattsville branch from as far as Oxon Hill to submit a petition with 253 names asking the board to reconsider its earlier vote to add 2 1/2 hours to their 37 1/2 hour work week without more pay.

The board had asked the county's 336 library employes to work the extra hours to bring the week in line with that of other county employes and to adapt to the county's fiscal constraints. The library workers, none of whom are unionized, oppose the move since they, like other county employes, received no raises this year. They said the move would actually decrease their vacation, sick leave, and pension benefits.

Said Marion Hargrove, a 15-year veteran: "I have even come to believe that the recent decision is part of a systematic campaign to strip library employes of other benefits."

Hargrove, one of a half dozen speakers on behalf of the librarians, echoed the concerns of other librarians for job security in the face of recent cost-cutting efforts.

Other speakers said they were also frustrated by having to punch time clocks unlike other professional workers, the lack of promotional opportunity, the lack of control over their time and the lack of respect for them as professionals.

"It bothers me, that the librarians are not consulted when things very close to their income and the way they live are thrust upon them. These are people whose dignity must be respected by the board," said Albert Herling, a former president of the county's Friends of the Library.

Goldsmith said the board will consider the petition at a closed meeting next Thursday.