The four defendants sentenced last month to up to 30 years in prison for stealing $5 million worth of ancient coins from the Fogg Art Museum will appeal their convictions, an attorney for one of the defendants said yesterday.

Barry Haight, the defense attorney, said yesterday the defense will appeal the case to the Massachusetts Appeals Court sometime in the near future on the grounds that certain crucial rulings from the bench were incorrect.

Haight said the introduction of coin books bearing the defendants' finger prints should have been declared inadmissable as evidence.

Daniel Steiner '54, general counsel to the University, said he hoped the threat of heavy sentences would cause the defendants to disclose the location of $1 million worth of coins that are still missing from the Fogg.

Haight said that an exchange of a lesser sentence for the recovery of the missing coins was impossible because "such a deal would assume the defendants know where the coins are, but they are innocent."

Harry Mezer, assistant district attorney for Middlesex County, said yesterday the possibility of a deal "was left open--it was the defendants' choice."

Mezer said he was concerned solely with the conviction of the alleged burglars.

"All we're interested in was the conviction, we know nothing about the coins. We got the conviction and that should make Harvard all the more happy."

Mezer, however, said he was unhappy with the sentences.

Mezer said the prosecution team had made its own recommendations to the judge before sentencing. He would not specify the proposal, but said that "the Judge did not follow our recommendations."

Three of the defendants--Anthony B. Vaglica of Waltham, Carl Dixon of Jamaica Plain, and Louis R. Matha of Cambridge--received prison sentences ranging from 15 to 30 years. Maria Magna of Cambridge was convicted as an accomplice.

The four allegedly stole 5000 rare ancient Greek and Roman coins from the Fogg Art Museum on December 2, 1973.

Both Mezer and Steiner said there is still hope to find the missing coins.

"That side of the investigation is still open," Mezer said. "The FBI and police are still looking," he added.

Experts believe the burglary was the largest art theft in history