Pinus rigida 
Placodium citrinum 
Plagiochasma rupestre 
Wrightii. . . . 
Plagiochila alaskana 
arctica 
asplenioides 
Austini 
columbiana. . . . 
florida-na 
Fryei. 
ludoviciana .... 
“ Smallii . . 
Sullivantii 
undata 
virginica 
Plagiothecium 
denticulatum 
striatellum . . 
sylvaticum . . 
Platysma ciliare 
Pleuroclada albescens 
Pleuropsis sericeus 
Pleuropus 
Pleurozia purpurea 
Pogonatum tenue 63, 
Pohlia afrocruda 
“ elongata 64, 
“ nutans 
Polytrichum commune 
keniae 
ohioense. .. 63,64,65, 
piliferum 
Porella Bolanderi 
“ laevigata 
“ navicularis 
“ pinnata 
“ platyphylla 89, 
‘ ‘ platyphylloidea 
“ rivularis 
“ Roellii 
“ Swartziana 
“ wataugensis 
Porotrichum 83, 
alopecurum 
Laurentia 
Prasanthus suecicus 
Preissia quadrata 
Pseudopohlia 
Pterogonium ornithopodioides 
Pterygophyllum acuminatum 
Ptilidium californicum 
ciliare 
pulcherrimum 
Ptychocoleus heterophyllus . . . . 68, 
Ptychomitrium incurvum 
Pylaisia Schimperi 66 
Pyxine sorediata 30, 31 
Radula arctica 89 
“ australis 89 
“ Bolanderi 89 
“ complanata 56, 89 
“ flaccida 89 
“ Hallii . 89 
“ Lescurii 89 
uLAAJiuud. o'-') o/» oy 
(PL XXV, figs. 1-11) 
“ polyclada 89 
“ Sullivantii 89 
“ tenax 89 
Ramalina farinacea 30 
Raphidostegium Kegelianum 28 
subpinnatum 28 
Reboulia hemispherica 87 
Rectolejeunea Berteroana. 90 
Brittoniae 90 
Maxonii 68, 90 
phylloloba 90 
Rhabdoweisia crispata 63,65 
Rhabdoweisiella 17 
Rhacocarpus Humboldtii 92 
Rhacomitrium aciculare 14,66 
, " affine 3, 6, 7 (PL VI, 
figs. 1-11), 14 
affine obtusum 6 
alare . 92 
alopecurum ........ 6 
alternatum 6 
brevipes 3 
durum 92 
canescens 9, 10 (PL 
VIII, figs. 1-9), 14 
canescens epilosum 9, 
10 (PL IX, figs. 1-2) 
canescens ericoides 9,11 
(PL X, figs. 1-4) 
canescens lutescens 7 
muticum 9 
cyclodictyon 1 (PL 
I, figs. 1-8), 6, 14 
defoliatum 92 
depressum 14 
ericoides 9 
fasciculare 14, 15 (PL 
XIV, figs. 1-6), 16 
heterostichum 1 (PL 
II, figs. 1-6), 3, 14 
heterostichum alo- 
pecurum 6 
heterostichum graci- 
lescens 6 
50 
93 
87 
87 
88 
88 
88 
88 
88 
88 
88 
88 
88 
88 
88 
88 
94 
66 
66 
66 
31 
89 
92 
17 
89 
64 
92 
66 
66 
64 
92 
66 
29 
89 
89 
89 
89 
94 
89 
89 
89 
89 
89 
84 
24 
95 
88 
87 
1 7 
92 
19 
89 
89 
89 
90 
6 7 
