A further contrast between the general plans of Oraibi and Zuñi is afforded in the different manner in which the roof openings have been employed in the two cases. The plan of Zuñi, Pl. LXXVI, shows great numbers of small openings, nearly all of which are intended exclusively for the admission of light, a few only being provided with ladders. In Oraibi, on the other hand, there are only seventeen roof openings above the first terrace, and of these not more than half are intended for the admission of light. The device is correspondingly rare in other villages of the group, particularly in those west of the first mesa. In Mashóngnavi the restricted use of the roof openings is particularly noticeable; they all are of the same type as those used for access to first terrace rooms. There is but one roof opening in a second story. An examination of the plan, Pl. XXX, will show that in Shupaúlovi but two such openings occur above the first terrace, and in the large village of Shumopavi, Pl. XXXIV, only about eight. None of the smaller villages can be fairly compared with Zuñi in the employment of this feature, but in Oraibi we should expect to find its use much more general, were it not for the fact that the defensive site has taken the place of the close clustering of rooms seen in the exposed village of Zuñi, and, in consequence, the devices for the admission of light still adhere to the more primitive arrangement (Pls. XL and XLI). The highest type of pueblo construction, embodied in the large communal fortress houses of the valleys, could have developed only as the builders learned to rely for protection more upon their architecture and less upon the sites occupied. So long as the sites furnished a large proportion of the defensive efficiency of a village, the invention of the builders was not stimulated to substitute artificial for natural advantages. Change of location and consequent development must frequently have taken place owing to the extreme inconvenience of defensive sites to the sources of subsistence. The builders of large valley pueblos must frequently have been forced to resort hastily to defensive sites on finding that the valley towns were unfitted to withstand attack. This seems to have been the case with the Tusayan; but that the Zuñi have adhered to their valley pueblo through great difficulties is clearly attested by the internal evidence of the architecture itself, even were other testimony altogether wanting. MOEN-KOPI. About 50 miles west from Oraibi is a small settlement used by a few families from Oraibi during the farming season, known as Moen-kopi. (Pl. XLIII). The present village is comparatively recent, but, as is the case with many others, it has been built over the remains of an older settlement. It is said to have been founded within the memory of some of the Mormon pioneers at the neighboring town of Tuba City, named after an old Oraibi chief, recently deceased.