— vii — 



Pellia epiphylla 43> 67 



" Fabroniana 67 



Peltigera apthosa 78, 82 



" canina 82 



" " membranacea. .... 82 



" " spuria 82 



" polydactyla 82 



" venosa 82 



Pertusaria loi 



" amara 82 



" leioplaca 82 



" multipuncta 82 



" pertusa 82 



" pustulata 82 



Philonotis fontana 67 



Physcia aipolia 84 



" crispa 75 



" interrupta var. sorediosa. . 76 

 " obscura var. endochrysea . . 68 



" pulverulenta 84 



tenella 84 



Picea sitchensis 77 



Pilophoron cereolus 80 



" " acicularis 80 



Pinus contorta 77 



" monticola 77 



" rigida 64, 72 



Plagiochasma intermedium 17 



" japonicum 17 



" rupestre 60, 61 



" Wrightii 17, 60, 61 



Plagiochila 45> 67 



" asplenioides 61 



Plagiopus Oederi 67 



Plagiothecium denticulatum 67 



" latebricola 48 



Platygyrium repens 98 



Platysma diffusum 73 



Pleuridium 29, 49, 50 



" alternifolium 50, 51 (PI. V) 



" " var. Howei 50 



" Bakeri 50 



Bolanderi 50, (PI. IV) 



" stramineum 50 



Pogonatum brevicaule 62 



Pohlia pulchella 90 



Polyporus 79 



Polytrichum alpinum 67 



" striatum 41. 44 



Populus trichocarpa 77» 79 



Porella.. 46 



" pinnata 67 



platyphylloides 67 



Porothaimnium parvirete 47 



" porrectulo 47 



Porotrichodendron superbum 47 



Porotrichum cavifolium 47 



Pottia... 29 



Preissia 18, 19 



" quadrata 67 



Prunus emarginata erecta 77 



" maritima. 63 



Pseudotsuga mucronata 76, 79, 80 



Psychotria undata ; 26 



Pterygophyllum acuminatum 100 



" acutifolium 100 



" lucens 100 



Pterygynandrum filiforme 67 



Ptilidium ciliare 44 



" pulcherrimum 46 



Ptilium crista-castrensis.. . . 44, 67, 99 



Pyrenula nitida 90, 99 



" glabrata 99 



Pyrularia pubera 100 



Pyrus diversifolia 77 



" sitchensis 77 



Radula 46 



" complanata 61, 67 



" flaccida 24 



" obconica 67 



Ramalina inflata 83 



" Menziesii 48 



" reticulata 83 



Reboulia 18 



" hemispherica 60, 61 



Rhabdoweisia denticulata 67 



Rhacomitrium aciculare 



92,93,95 (96, PI. XXII) 

 " aciculare Nevii 



95 (96, PI. XXIII) 



" affine 92, 93 



" canescens 91-93 



" cyclodictyon.. . . 92,93 



" depressum 



92, 95 (96, PI. XXIV), 98 



" fasciculare 93 



" heterostichum 92 



" lanuginosum.. . . 92,93 / 



" Macounii 92, 93 



" microcarpum 92 



Nevii 95 



" Palmeri 9i, 93 



" patens 



32, 92, 93 (94, PI. XXI) 



" protensum 98 



" sudeticum 92, 93 



" " occidentale... 93 



" varium. . . . . 91,92,93 



Rhamnus Purshiana 77 



Rhizocarpon geminatum 80 



" geographicum. ... 80, 82 

 " petraeum 80 



