As you stand facing the portraits, on the left proceeding away from the door are:

David Starr Jordan
President, 1891-1913
artist: Mary Curtis Richardson

Ray Lyman Wilbur
President, 1916-1943
artist: H. Hubbell

J. E. Wallace Sterling
President, 1949-1968
artist: Albert Murray

Richard W. Lyman
President, 1970-1980
artist: Arthur DeCosta

On the right proceeding away from the door are:

John Casper Branner
President, 1913-1916
artist: Mary Curtis Richardson

Donald B. Tresidder
President, 1943-1948
artist: Arthur Cahill

Kenneth S. Pitzer
President, 1968-1970
artist: Arthur W. Palmer

Donald Kennedy
President, 1980-1992
artist: Brigitte Carnochan