Plate S. 



Left: Ncstiii.u- tree of bufllelieail. r.uff;il<> Lake. Alberta. June S. 1020. The 

 liiwei' li()le rtiiitained 12 fresh eggs. 



Eight. Another nesting tree in tlie same locality. June 2. 1920. "The 

 piiotograph shows how far the eggs were below the entrance hole." Both 

 pbotograiiiis jiresentecl by Mr. (!. IL Lings. 



319 



