Analytic Keys to the Species of Mosses. 
81 
2. Alar cells not distinct, often quadrate. 
a. Plants very stout (5—6 mm. thick) f leaves transversely 
rugose ..H. robustuin, 145, 
}). Plants much more slender (2 mm. or less thick), leaves not rugose. 
H. geminum, 102, 
H. plicatile, 157. 
H. Yaucheri, Lesq. 1 
H. pulchelluin, 101. 
Costae 2, thick, reaching the middle . 
Ecostate or shortly bicostate. 
Irregularly branched. 
Leaf margins reflexed, shortly bicostate 
Leaf margins plane, shortly bicostate 
Leaf margins plane, ecostate .... 
Regularly pinnate. 
Plants very large (to 15 cm.), capsule arcuate, stem 
leaves plicate.H. Crista-castrensis, 146. 
Plants smaller (usually less than 5 cm.), capsule not 
arcuate nor stem leaves plicate. 
Pericheetial leaves plicate. 
Leaves quite entire.H. complexiim, 160. 
Leaves serrulate at apex. 
Inner perichsetial leaves costate . . . H. fertile, 149. 
Inner perichsetial leaves ecostate . . H. Iiamulosum, 150. 
Perichsetial leaves not plicate H. subimponens, 156.. 
1 Renault! & Carclot: Bot. Gaz. xiv. (1889) 100. 
6—A. & L. 
