520 INDEX. 



]'i IV III , IMexif'an . 37 



siiigle-lcal' -57 



Piniis arizonica 3S 



(•('in]>r()i(les 37 



fhihuahuana 39 



ooiiltcri 39 



edulis 37 



mayriana 38 



monopliylla 37 



ponderosa 38 



salnniana 39 



strobifcjrmis 3(1 



torroyana 38 



Pitahaya 05, (IB 



(lulce ()(i 



Plains mouse, Chiliualiua 389 



San Diego 398 



Sonora 384 



Western Desert 394 



Plants gathered by the International l^oundary Commission 130 



Plat anus occidentalis 56 



racemosa 56 



wrighti 56 



Playas valleys 11, 15 



Populus angustifolia. 47 



f remontii 48 



tromuloides 47 



wislizeni 48 



Post Spring, Fort Huaelnua 102 



Pozo de Luis, Mexico 18, 19, 114, 115 



flora of 115 



Pozo Verde 113 



Mountains 113 



Prairie-dog, Arizona 340 



short-tailed 345 



Pride of India 69 



Prong-horn, Mexican 221 



Prong-horns 220 



Prosopis glandidosa 59 



odorata 59 



velutina 60 



Prunus dcmissa - - - 58 



ilicifolia 58 



integrifolia 58 



salicifolia 58 



Pseudotsuga mucronata - 39 



•Ptelia l)etulifolia 62 



cognata 62 



jucunda 62 



sancta 62 



trifoliata *'2 



'Puga, Guillermo B . y, International Boundary Commissioner 1 



Quaking asp 47 



