The thirteenth ballot for mayor could have been a lucky one for Cambridge City Councillor Anthony D. Galluccio. But his fellow conservative council members failed to support him.

In a surprise move during Wednesday night's emergency council meeting, Councillor Kenneth E. Reeves '72, the former mayor, cast his ballot for Galluccio, who is one of four councillors elected last November under the conservative Alliance for Change slate.

Reeves' ballot would have provided the fifth and decisive vote for Galluccio had the three other Alliance councillors followed suit. Acting Mayor Francis H. Duehay '55 has consistently received the support of the four liberals endorsed by the Cambridge Civic Association (CCA).

But Alliance Councillors Sheila T. Russell, Michael A. Sullivan and Timothy J. Toomey Jr. each voted for themselves Wednesday. So no candidate received a majority of votes on the nine-member council.

Galluccio said yesterday that he was "stunned" that the Alliance councillors did not support him in his bid to become the city's first conservative mayor since 1988.

"I'm upset they decided to pass up our only opportunity so far to have an Alliance mayor," said Galluccio, who had supported Russell until Reeves' surprise vote Wednesday.

"For them not to extend some good faith deference to me is inexcusable," he said.

In each of the previous ballots, Reeves voted for himself and the remaining conservatives split their ballots.

Reeves said yesterday that he threw his vote to Galluccio because the two share views on education and race-related matters.

"[Galluccio] understands that the working-class blacks and whites need to have a union," Reeves said. "That's something I want to do, and he says that's his objective too."

But CCA-endorsed Councillor Henrietta A. Davis said that the two councillors have espoused markedly different policies in the past.

The two disagree on fundamental issues such as rent control and the opening of an alternate school for disruptive students, according to Davis.

"They just don't seem like they necessarily play on the same team," she said.

Russell, an active mayoral candi- date, said that the other Alliance councillors did not vote for Galluccio because they had not been informed about Reeves' plans.

"We didn't know if Galluccio and Reeves made some kind of deal," she said. "So we couldn't vote for it."

Russell also said that she suspects Reeves is not a true supporter of Galluccio and would have changed his vote had the other councillors voted for him as well.