KEY TO THE GENERA AND SPECIES OF BRITISH MOSSES. 43 
190 / Ls: strongly pee? when moist, acuminate 191 
(Ls. not plicate, or only subplicate when moist 192 
191 / Cells all long te DOE TOW, 4: ciish pa ccnp teed wieapicinds 198 
(Cells oval, shorter at sides of leaf below midd!e.............+- Lew 
Leaf-cells all short, not twice as long as wide; or long-oval in centre 
1024 and short at sides of leaf 193 
Cells all lon As = narrow (exc. at angles only) 198 
193 | Ls. subplica - margin recurved alm. to apex ...... Hedwigidium 
(Ls. not plisats ‘a moist; margin plane i in upper part............ 194 
19, 4 ( = Prt ntire, smooth 1 
cre or less serrulate 196 
195! * w. rounded, subacute points; cells r. lax........csecseeeeeees Myrinea 
(Ls. w. long, narrow acumen Habrodon 
196: (Le. soit ais ove, smooth, over half a line long ......... ieilisie 
(Ls. finely serrulate, usu. pa ioe. y. small 197 
197! ite retro ores | or siege te, v. concave and imbric....Myurel 
(St. Is. e or acu squarrose or spreading ...Heterocladium — 
(St. ‘aes usu. Metis ; ‘e se rapeedss caps. RNIDORR GE aey-onl OMEN 
met ony not 3-ra — d; caps. 
199 | Ls: v. concave, imbric., wich: with v. long apiculus epee 
ite. without elongatoa apiculus 200 
990 { Branch Is. m. or 1. one or apiculate, usu. entire 201 
(Ls. acute or acumina 203 
901 / Terrestrial plant 202 
(Aquatic or marsh plant Hypnum 
999 / St- and Is. pale ; auricles of small, opaque cells...... Cy ylindrothecium 
(St. red, or else auelee bea = BN isi itescsenps ec snnice Hypn 
203 | Ls- distinctly toothed 
( Ls. entire (exe. at sith ath apex only) one 
904 / 5t- Is. wide-ovate, sharply serrate, shortly acum. .........Hyocomium 
(Ls. finely ore ge long, fine acumen 205 
905 | US. strongly squar ecurved Hypnum Halleri 
(L S. spreadi ng or scapes Plagiothecium 
206 Plant v. slender, ae a-like; 1s. v. minute............ Amblystegium 
( Plant usu. larger, with easily visible leaves 207 
207: { Ls. acute, or shor “dy acuminate 208 
(Ls. with long narrow acumen 209 
208 ! Ls. elliptic- ga margin rsa de throughout...Rhyncost. doenees 
( Margin erect, exc. at ba 
209 | Ls. m. or 1. squarrose, or very Spreading ..........ccsseeseeceeee ne 
| Ls. imbricate (and plicate), or subsecund 210 
210: (Ls. reddish, or 1. ase at least when dry ......... Orthothectum 
(Ls. not vedatish nor plic 211 
211 { Capsule erect, lid conic; te ovate below Pylaisia 
| Caps. cernuous, or erect w. rostrate lid; Is. lane. ............ Hypnum 
219! Ls. with a distinct border 213 
(Ls. not evidently bordered 214 
(St. long, aquatic; n. reaching apex or excurrent ......... goer eatin 
213, (St. v. short, terrestrial ; nerve uot reaching apex ............ Dalton 
* 
(Cells short, not twice as long as wide (often papillose}............... 215 
a (Cells at least 2 or 8 times as long as wide (smooth) 224 
