Major contributions to area colleges dominate the day's news.

* In Washington, Catholic University has announced a record single gift of $2 million has been given by an anonymous donor. With matching funds of $1.5 million from the National Endowment for the Humanities, the Andrew W. Mellon Foundation and others, it will provide for expansion and renovation of the campus library named for John K. Mullen of Denver and for endowment of a chair in early Christian studies.

* In Chestertown, Md., Washington College disclosed it has been promised a new building, costing perhaps as much as $5 million, by Gaithersburg builder and financier Eugene B. Casey. His wife, Betty Casey, is a 1947 alumna and member of the college's board of visitors and governors.

Both gifts are noteworthy, for different reasons.

In a city with many marvelous libraries, the collections of Catholic's Mullen Library are often overlooked. It contains materials on Catholic Americana and on Christian Oriental studies, as well as the family library of Pope Clement XI, who served in the 18th century. The Rev. William J. Byron, the university president, said he was elated and said the gifts would enhance the school's already strong scholarly traditions.

The Casey gift to Washington College, an 800-student liberal arts school, is unique in that the faculty and student body will be asked to help decide what the new building will be. Prizes will be awarded for the best proposals.