Cheyney C. Ryan, a former student and SDS co-chairman severed from the University last year for his role in an obstructive protest, was sentenced to two months in prison and fined $200 yesterday for demonstrating on campus during the national student strike last May.

Judge M. Edward Viola of Middlesex Third District Court announced the punishment after ordering the removal from the courtroom of about 75 spectators who had hissed and booed him frequently during the tumultuous three-hour trial.

Police beat and shoved many of the spectators out of the building and forced them all away from the immediate area. Four persons-including three Harvard students-were arrested on charges ranging from contempt of court to assault and battery on a police officer. The four-released without bail charges-will come to trial in District Court on Nov. 13.

Ryan-whom Harvard had had indicted last July for allegedly taking part in two obstructive pickets of University Hall May 8 and May 11-is planning to appeal the decision. He was released on personal recognizance immediately after the trial.

Four high-ranking Harvard officials-President Pusey, Deans Dunlop and May, and Archibald Cox, the University spokesman who swore out the warrant against Ryan-received subpoenas from the defense to testify at the trial. All but Pusey appeared.

When Ryan-who conducted his own defense-attempted to initiate contempt of court proceedings against Pusey, Viola invalidated the subpoenas on the grounds that they had not been filed through the District Court clerk.

Ryan acknowledged that he was guilty of the second trespass charge and contested the first. He stated, however, that other severed students who reappear on campus are not normally arrested for trespass and that his trial constituted political repression.

May testified that Harvard would not automatically take legal action against all such ex-students even though they are in violation of University rules, but he denied that the decision to prosecute Ryan was a political one. He explained that the obstructive acts in question were serious enough to be settled "through the intermediary of a court."

(Cox issued a statement last night explaining more fully the University's position on Ryan's arrest and conviction. The statement appears at the conclusion of this article.)

David A. Harnett, director of Advanced Standing, testified that he had seen Ryan at University Hall on May 8 at the time of the picketing. Two members of SDS stated. however, that Ryan was attending an SDS meeting in Boston at that time.

During his summation, Ryan remarked, "Since the Harvard administration has run this trial from the word go, I have no doubt that the judge will believe what the Harvard administration says." Shortly afterward, Viola had the courtroom cleared.