MUSCI 



149 



In most Bryaceas the tissue of the leaf is nearly homogeneous, with the 

 exception of the margin and an elementary midrib composed of elongated 

 prosenchymatous cells; but in Leucobryum (Hpe.) the small chloro- 



B 

 A V, c 



Fig. 117. — Sporange o^ Poly trichuni commune, showing 

 epiphragm. A , covered by calypter ; B, with calj"pter 

 removed ; C, with opercule removed (magnified). 



Fig. 1 1 3.— Sporange of Hypnnm 

 populcum, showing peristome 

 (magnified). 



phyllous cells interlace among large empty cells with circular orifices in 

 their walls, as in Sphagnum, 



The very numerous genera of Bryaceaeare further classified as under. 



Acrocarpi. — Fructification produced at the extremity of the branches. 

 Ilhistrative ge?iera : — Weissia (Hedw.), Dicranum (Hedw.), Leucobryum 

 (Hpe.), Pottia (Ehrh.), Tortula 

 (Hedw.), Bartramia (Hedw.), 

 Encal\'pta (Schreb.), Fissidens 

 (Hedw.), Grimmia (Ehrh.), Or- 

 thotrichum (Hedw.), Zygodon 

 (H. «S: T.), Tetraphis (Hedw.), 

 Buxbaumia (Hall.), Polytri- 

 chum (Dill.;, Aulacomnion 

 (Schw.), Br>-um (H. & T.), 

 INInium (B. & S.), Funaria 

 (Schreb.), Splachnum (B. ^ S.), Tayloria (Hook.), Barbula (Hedw.), 

 Ceratodon (Brid.). 



Pleurocarpi. — Fructification lateral, not at the extremity of the prin- 

 cipal branches. Illustrative genera : — Hedwigia (Ehrh.), Fontinalis (L.), 

 Hookeria (Sm.), Hypnum (Dill.), Leucodon (Schw.), Neckera (Hed^-.). 



Fig. 119. — Peristome ot 

 A trichu7>i undulaUnn 

 (magnified). 



Fig. 120, — Peristome ot 

 Cinclidijun stygium 

 (magnified . 



Literature (in addition to the papers already quoted). 



Philibert— (Peristome) Rev. Bryol., 1884-1S88. 



Vaizey— (Polytrichace^) Journ. Linn. Soc, xxiv. (iS8S,\ p. 162. 



