THE Index of Christian Art is a division of the Department of Art and Archaeology of Princeton University. The purpose of the index is to catalogue by subject and iconographic type all the published monuments and objects containing representations of Christian subjects dated before the year 1400.1 To this end two principal files are maintained, the Subject File and the Monuments or Photographic File. At the present time there are about 35,000 monuments and objects filed under more than 21,000 headings or titles, the whole consisting of more than 425,000 typed cards. These are illustrated in the Monuments File by more than 80,000 photographs.