84 KEY TO THE GENERA AND SPECIES OF BRITISH MOSSES, 
at least some such elementary introduction as that in Bagnall’s 
Handbook of Mosses. 
The term ‘cells,’ when used without further qualification, 
refers to the average cells of the upper part of the leaf, say those 
about one-third of its length from the apex. Cells are described as 
“lax” when ag cavity is s 18 » or more wide, irrespective of its 
length, and as ‘‘close’”’ or ‘‘dense’’ when the cavity is narrower 
than this 
The iatleing contractions are used in the Ke 
alm. almost, perich. ls. perchetial leaves. 
br. branch. perist. _ 
cal. calyptra. perist. t Sees teeth. 
caps. capsile, pl. ple 
exc. except. r. rather 
fl wer. se. scarcely 
lane. lanceolate. st. stem. 
ls. leaves. usu. usually, 
m, or l. more or less. Vv. very. 
n. nerve. w. with. 
The termination ‘‘ate”’ is often omitted ; as, subul. subulate. 
KEY TO THE GENERA. 
* 
1 Branch leaves with spiral fibres in cells Sphagnum 
Cells without spiral fibres 2 
9 nee opening by slits; pl. blackish, v. fragile Andreaa 
ps. opening by a lid, or bursting irregularly 3 
* 
8 foun closed, without lid, usu. immersed, pl. minute ..........s0ee0. 4 
Caps. with lid (or oper); or pl. without fruit.22.i.c 13 
4{ Ca immersed 5 
| Caps. exserted Phascum 
5 Pl. growing from persistent green protonema 6 
| Protonema not persiste 
6 Ls. more or less lanceolate, tapering to a point ............ Ephemerum 
{ts narrow-lingulate, ust. recurved .........cevecscevecerseras Ephemerella 
7 Caps. sessile, globose; spores few, large, angular ............ Archidium 
Caps. sho. a stalk usu. ance ed; eitae smaller, rounded......... 8 
g { Caps. with minnte, persistent lid; Is. curled be is pers Systegium 
Caps. ibsiak 4 a distinct lid; pies earcely curle 9 
9 {8 Ls. ret or subulate, smoo Pleuridium 
vate, ovate- lanceolate, or obovate 10 
10 be setae above, n. ncirzomnion 4 cells v. lax ............Physcomitrella 
\ Te. entire, or erose n apex usu. excurrent 11 
a Saka not (or acces vuintolk: 2 or 3 inner perich. ls. y. 
14 concave, usu. serrul. at APeX......-.....sseeee Spher — 
Bers spiulates . entire, tapering 
39{ Pl. brownish ; vate-acumin.; cal. conic, lobed.........Microbyrum 
{pr usu. green ; =a i dbloap-lasaiblaths cal. cucullate............Phascum 
