Tom C. Clark, 77, one of the hardest-working jurists in the long history of the American judiciary and a member of the United States Supreme Court for 18 years, died Sunday in New York.

He died in his sleep at the home of his son, Ramsey Clark, a former Attorney General of the United States, a post Justice Clark himself had held before his appointment to the high court in 1949 by President Truman.

Typically, Justice Clark, was at work during his stay in New York. He had gone there to assist the federal appeals court in the circuit that includes that city.

The Texas-born Justice left his seat on the Supreme Court in 1967 after President Johnson appointed his son to the Attorney Generalship. The elder Clark acted to avert any appearance of conflict between his duties and that of Ramsey Clark.

Praise for Justice Clark and his long career in pursuit of improvement in the administration of justice came last night from various colleagues, including the present Chief Justice, Warren E. Burger.

Burger pointed particularly to Justice Clark's almost legendary devotion to duty and hard work, and to the fact that he was the only man in the nation's history to sit as a judge in each of the 11 judicial circuits of the United States.

Justice Clark's career in Washington spanned several decades, beginning in 1937 when he came here as a special assistant to the Attorney General. He was himself appointed to that post in 1945 by President Truman.

Justice Clark was a native of Dallas, and earned his law degree in 1922 at the University of Texas law school.

Justice Clark succeeded Frank Murphy on the Supreme Court and was succeeded by Thurgood Marshall.

There was no immediate word on funeral arrangements.