Yarrow, dwarf alpine, 164. 
Yellowlegs, 110. 
Zamelodia melanocephala, 126. 
Zapus nontanus, 74, 81. 
pacificus, 99. 
trinotatus, 69. 
trinotatus alleni, 98. 
INDEX 179 
Zeouaidura macroura, 111. 
Zones, Life, 52-68, 
Alpine, 67-68. 
Canadian, 61-64, 
Hudsonian, 64-67. 
‘Transition, 54-61. 
Upper Senoran, 53-54. 
Zonotrichia leucophrys, 125. 
c 
