NO. 12 



SMITHSONIAN EXPLORATIONS, I917 



121 



situated on points of the mesa rim or perched on fallen angular 

 rocks on the floor of the canyon. It may be mentioned that their 

 walls are constructed of good masonry, which has effectually resisted 

 the erosive power of the elements. 



Fic. 126. — Group of rums m Holly Lanyou. Photograph hy J. Wirsula. 



Fig. 127. — Horseshoe Ruin, Hackberry group. Photograph by J. Wirsula. 



The early builders were prone to introduce curved walls in these 

 buildings ; they were partial to circular, oval, and D-shaped struc- 

 tures, although square and rectangular buildings are common. They 

 paid little attention to leveling the foundations on which the walls 



