In what some observers viewed as the mark of style of American Catholic leadership, the nation's Catholic bishops passed over the church's eight American cardinals in choosing representatives to the international Synod of Bishops in 1980.

In their semiannual meeting in Chicago last week, the National Conference of Catholic Bishops elected three archbishops and one auxiliary bishop - the oldest of whom is 15 - to represent the American church at the important Vatican session nex year.

Elected were Archbisop John R. Quinn, 50, of San Francisco, president of the NCCB; Archbishop Joseph L. Bernardin, 51, of Cincinnati, immediate past president of the NCCB; Auxiliary Bishop J. Francis Stafford, 47, of Baltimore, and Archbishop Roberto Sanchez, 45, of Santa Fe, NM.

It was the first time the bishops have failed to include at least one cardinal in a snyod delegation. The international snoyds, held every three or four years, grow out of the Second Vatican Council's call for bihops of the church to join with the pope in guiding the church.

The forthcoming snyod is considered particularly important since it will be the first in the pontificate of Pope John Paul II, who was himself deeply involved with previous synods while he was still bishop of Krakow.

In recent years the preponderance of those named bishops in this country have been younger men deeply committed to the Vatican Council reforms.

The 1980 synod will deal with the problems of the family, a topic chosen by the Pope Paul VI. Bishop Stafford heads the U.S. hierachy's committee concerned with family life.