Macgill James, 85, assistant director of the Smithsonian Institution's National Gallery of Art from 1940 to 1956, died Aug. 29 in his home in Washington. He had a circulatory ailment.

Mr. James was born in Catonsville and attended Harvard and Columbia universities. He served with an Army field artillery unit in France during World War I. After that, he worked in the family lumber company in Baltimore, and was director of the Peale Museum in Baltimore from 1933 to 1940.

He became the first person to hold the post of assistant director at the National Gallery, joining the staff there a year before it opened to the public in 1941. Upon retiring from the Gallery, he became curator of "Biltmore House," an estate in Asheville, N.C. He returned to this area in 1957.

Mr. James was the illustrator of a book about a World War I artillery unit, and a coauthor of "Great American Paintings from Smiber to Bellows 1729 to 1924."

His first wife, Bruce Kinsolving James, died in 1946.

Survivors include his wife, the former Caroline Ross Rogers, of Washington; two sons by his first marriage, Arthur Lee James of Brookside, N.J., and Patrick Macgill James of Nara, Japan; a sister, Marjorie Fisher of Glydon, Md., and nine grandchildren.