The transom bars over exterior doorways of houses probably bear some relation to a feature seen in some of the best preserved ruins and still surviving to some extent in Tusayan practice. This consists of a straight pole, usually of the same dimensions as the poles of which the lintel is made, extending across the opening from 2 to 6 inches below the main lintel, and fixed into the masonry in a position to serve as a curtain pole. Originally this pole undoubtedly served as a means of suspension for the blanket or skin rug used in closing the opening, just as such means are now used in the huts of the Navajo, as well as occasionally in the houses of Tusayan. The space above this cross stick answered the same purpose as the transoms of the present time. A most striking feature of doorways is the occasional departure from the quadrangular form, seen in some ruined villages and also in some of the modern houses of Tusayan. Fig. 82 illustrates a specimen of this type found in a small cliff ruin, in Canyon de Chelly. Ancient examples of this form of opening are distinguished by a symmetrical disposition of the step in the jamb, while the modern doors are seldom so arranged. A modern example from Mashongnavi is shown in Fig. 83. This opening also illustrates the double or divided transom. The beam ends shown in the figure project beyond the face of the wall and support an overhanging coping or cornice. A door-like window, approximating the symmetrical form described, is seen immediately over the passage-way shown in Pl. XXII. This form is evidently the result of the partial closing of a larger rectangular opening. [Illustration: Fig. 82. An ancient doorway in Canyon de Chelly cliff ruin.] [Illustration: Fig. 83. A symmetrically notched doorway in Mashongnavi.] [Illustration: Plate XCIII. Upright blocks of sandstone built into an ancient pueblo wall.] [Illustration: Fig. 84. A Tusayan notched doorway.]