Pogonatum brevicaule 19 



Pohlia albicans 55 



cruda 88 



" elongata var. longicolla 46 



" Lescuriana 89 



" nutans 6, 42, 64 



' proligera 55 



Polytrichum commune 7 



" Jenseni 48 



" subformosum 28 



Porella laevigata 31 



pinnata 31. 53 



" platyphylla 3i> 50 



" platyphylloidea 50 



" rivularis 31 



" Swartziana. 16 



" wautaugensis 16 



Porotrichum insularum 66 



Pottia intermedia var. litoralis. ... 45 



Prasanthus suecicus 16 



Pterigynandrum filiforme 56 



Pterobryopsis acuminata 28 



" subacuminata 28 



Pterygoneurum cavifolium 88 



Ptilium crista-castrensis 42,59 



Ptychodium albidum 29 



" pallescens 29 



Pylaisia intricata 56 



Pyrenothrix nigra 36 



Pyrenula epiphylla 74 



" mamillana 73 



Radula arctica 16 



" flaccida 16 



Hallii.. 16 



" Lescurii 16, 53 



" polyclada 16 



Radulum quercinum 24 



Ramalina 74 



" canaliculata 25 



" denticulata 63 



" linearis 63 



" reticulata 25 



Rectolejeunea Berteroana 16 



Rhacomitrium Flettii 86 



" protensum 48 



" sudeticum 55 



Rhacopi'um Perrieri 28 



Rhaphidostegium substrumulosum 45 



Rhizogonium spiniforme 66 



Rhytidiadelphus triquetrus 59 



Riccardia latifrons 51 



" palmata., 51 



pinguis 51 



Riccia albida 16 



" Beyrichiana 16 



" californica 16 



" Campbelliana 16 



" catalinae 16 



" hirta 16 



McAllisteri 16 



" terrestris 70 



Ricciocarpus natans 69 



" " var. terrestris 69, 70 

 Riella americana 16 



Scalia Hookeri 16 



Scapania americana 16 



" Bolanderi 16 



" convexula 16 



" cordifolia 16 



" dentata 16 



" Evansii 16 



heterophylla 16 



" Kaurini 16 



" spitzbergensis 16 



" subalpina ; . . . . 16 



Schistostega osmundacea 41 



Schlotheimia Sullivantii 17 



Schwetschkeopsis denticulata 56 



Seligeria calcarea 48 



" campylopoda 9 



" pusilla 48, 89 



" recurvata var. pleshkowi- 



ensis , 9 



Sematophyllum admistum 17 



" carolinianum 57 



" novae-caesariae ... 57 



" pungens 66 



" sericifolium 17 



subpinnatum 17 



" subsimplex 66 



Sphaerocarpos cristatus 16 



Sphaerophorus compressus 63, 64 



Sphagnum 74, 75, 78, 81, 89-96 



" alaskanum 85 



" annulatum 84 



auriculatum 84 



" balticum 84 



" compactum 53 



" cuspidatum . 81,85 



" " var. majus. . . 82 



" " " serrulatum 



81, 82 



" " " Torreyi.. 83 

 " Dusenii 84 



Fitzgeraldi 81, 82 



fuscum 76 (PI. V, f. 4) 



" Girgensohnii 53 



imbricatum. .76 (PI. V, f. i) 



" laricinum 83 



*' Lindbergii . . . 83 



" macrophyllum 82 



" magellanicum 80 



" mendocinum. ... 83. 84, 85 

 " " var. graciles- 



cens 85 



" Mohrianum 81 



" obtusum 86 



palustre. .76 (PI. V, f. 2, 77, 

 (f. 6-8) 



" pulchricoma 86 



" pulchrum 83 



recurvum.76 (PI. V, f. 3), 

 85, 86 



" squarrosum 85 



" subsecundum 73, 80-85 



" trinitense 81 



Sphenolobus exsectaeformis 30 



" exsectus 30 



