A former Harvard student- severed by the University last December for his part in an obstructive protest- will be arraigned in Cambridge Third District Court this morning on charges of appearing in two campus demonstrations during the national student strike last May.

Six Cambridge policemen- acting on a warrant obtained by Harvard last July- entered an SDS office in Boston late yesterday afternoon and arrested Cheyney C. Ryan '70 on two counts of criminal trespass, each punishable by 30 days in jail and a $100 fine.

Ryan, who is now a graduate student at Boston University, was released from the Cambridge police station last night on $500 bail.

There was no word available last night on the status of three other exstudents indicted at the same time as Ryan. The three, also members of SDS, are: Thomas R. Bailey '73, Emily T. Huntington '70, and Daniel P. Veach '70.

No Explanation

Nor was there any official explanation of the two-and-a-half-month lapse between the issuing of the warrants and Ryan's arrest. Archibald Cox, the University's demonstration troubleshooter who procured the warrants, could not be reached for comment.

Each of the four students is charged with appearing in one of two demonstrations at Harvard last May: an obstructive picket line around University Hall which demanded full pay for Harvard employees who were striking against the war, and another picket line which temporarily blocked members of the Committee on Rights and Responsibilities from entering their meeting rooms in Holyoke Center.

All four ex-students were suspended at the same time last year after they and 60 others had sat-in in Dean May's office to demand that Harvard promote its painters' "helpers" to full painter status.

The University subsequently promoted the helpers to apprenticeships and set up a training program under which they would become full painters in three years' time. A total of 16 students were ordered to leave Harvard for participating in the protest.