J. 



XXxiv KEY TO THE GENERA. 



o /Capsule immersed (or emergent only) 9 



\ Capsule exserted IO 



/Cleistocarpous; plants minute, growing on the ground E 



9 \Capsule with a lid (stegocarpous) ; usually larger, often on rocks or trees P 



/Peristome absent or rudimentary (or capsule cleistocarpous) G 



\Peristome present II 



Seta at end of stem, or of a leafy branch 12 



Seta, surrounded only by the perichaetial leaves at its base, at side of stem, or of 



{ a branch • 17 



/Capsule with apophysis as wide as, or wider than itself H 



\ Capsule without apophysis as wide as itself 13 



/Capsule striate, regularly furrowed when dry I 



3\Capsule smooth, or lightly and irregularly sulcate only when dry 14 



/Capsule erect or suberect IS 



\Capsule inclined or cernuous, or on an arcuate seta 16 



./Peristome teeth 4, or 16, entire, or slightly and irregularly cloven J 



■^Peristome teeth 16, deeply divided, * or 32 K 



.-/Peristome single L 



\ Peristome double M 



/Leaves single-nerved half-way or more 18 



'\Leaves nerveless or shortly 2-nerved 20 



o / Capsule erect, symmetric N 



\ Capsule cernuous, or curved, or on a curved seta O 



/Leaves nerveless ** or shortly 2-nerved 20 



y \Leaves single-nerved half-way or more 21 



I Cells short, not much longer than wide, or long-oval in centre and short at sides 



20-j of leaf p 



(Cells elongate, at least twice as long as wide Q 



I Plant bearing gemmjg or granular filaments on the leaves, or on special stalked 



21-j receptacles R 



|_ Plant without such appendages 22 



/Nerve very broad, about £ or more of base of leaf S 



\ Nerve narrow '. 23 



/Upper cells wide, 20 /i or more in shortest diameter T 



•'XUpper cells small or narrow, rarely over 15 fj. wide 24 



/Leaves obtuse and entire (or bluntly apiculate) \J 



*\Leaves acute, or obtuse and toothed 25 



'Stem (acrocarpous) usually erect or ascending, simple or dichotomously branched, 



never pinnate ; leaf-cells usually quadrate, rounded or hexagonal, rarely (as in 



Bryum, &c.) hexagono-rhomboid ; nerve often reaching apex or excurrent ...26 



Stem (pleurocarpous) usually prostrate or creeping, often long and with divergent 



lateral branches ; leaf-cells most usually rhomboid or linear, or oval or rounded, 



not quadrate ; nerve scarcely ever excurrent 28 



2 g /Leaves with enlarged, often brownish, angular cells V 



\ Leaves without dilated and coloured angular cells 27 



fLs. with excurrent nerve, or with long fine subula, into which the nerve runs.. W 

 ' \Ls. without excurrent nerve v 



long as wide rr 



25 



2 g/Cells short, not twice as long as wide Y 



\ Cells at least twice as long as w;' ' 



A. Leaves distichous, inserted in two rows only on the 



stem. 



/Leaves nerveless, cells lax >j . / . Schistostega 



(.Leaves single-nerved, cells small _ 2 



* Segments sometimes united by cross-branches. ** In Leucobryum apparently so only. 



