Harvard and Radcliffe seniors may be looking for shelter instead of sheepskin at next June's Commencement, Edward W. Burke, director of Cambridge Civil Defense indicated yesterday.

A mock hydrogen bomb raid will be held in 50 American cities on June 15, Radcliffe Commencement day, and will extend through the morning of June 16, when Harvard exercises are scheduled.

While Cambridge is not one of the cities definitely named to participate in the test, it is on a special list of cities, seven of which will be notified that they are "under attack" only at the first air raid warning.

Even if Cambridge were chosen to participate in the test, Burke expressed doubt that the city Civil Defense unit would be prepared to evacuate people from the city. "We aren't prepared to evacuate now, and probably won't be ready by June. But there is a possibility," Burke said.

Before the city could be evacuated, Burke said several questions would have to be settled. "We have no definite idea how to move children out of school buildings speedily in event of a raid," he said. Burke did not make any specific references to Harvard.