The judge in a Boston abortion case Wednesday rejected two motions for dismissal filed by the defense and set the trial date for January 6, 1975.

Judge James B. McGuire issued no opinion on his decision to allow the manslaughter case against Dr. Kenneth Edelin, a Boston City Hospital obstetrician, to go to trial in the Suffolk County Superior Court.

William P. Homans Jr. '41, attorney for Edelin, said yesterday that he is "disappointed" with the decision.

Homans argued ten days ago that the case should be dismissed because the prosecution had not shown that the fetus Edelin was accused of killing ever lived.

The prosecutor's contention that the fetus had breathed and maintained a heart beat independent of its mother was not backed up by any medical authority, Homans said.

Should Be Contested

Newman A. Flanagan, assistant district attorney, said at the hearing that this was a point that should be contested in trial.

The other motion for dismissal rested on the defense's claim the the defendant was not sufficiently informed of the charge against him.

Homans said that the indictment was unconstitutional, and that it conflicted with the Roe v. Wade decision of the Supreme Court in January 1973.

The prosecution claims that Edelin murdered a fetus that was at least 24 weeks old, in the process of an abortion last year.