In reviewing the works of the della Robbia family we encounter many monuments of glazed terra-cotta, which in some cases resemble those of the Robbias and confuse the student. In a number of instances documents have been discovered and copied by my friend Mr. Rufus G. Mather, con siderably amplifying the studies made a few years ago by Fabriczy and others, so that now it is possible to isolate the works of Benedetto and of Santi Buglioni. It has been considered worth while to publish these in a separate monograph. There is still considerable obscurity in the field oc cupied by the sons of Andrea della Robbia, an obscurity which perhaps may never be dispelled, but with the works of the Buglioni distinguished.