BRYOPHYTA 349 
Order ANTHOCEROTALES. Hornworts. Sporophyte elon- 
gated, with a columella and elaters, 
two-valved. 
Family 2. Anthocerotaceae. Gametophyte a flat 
thallus.—Anthoceros. 
Order MArcHANTIALES. Great Liverworts. Sporophyte 
rounded, without columella, indehis- 
cent. 
Family 3. Corsiniaceae. 
Family 4. Marchantiaceae. Gametophyte large, 
thallose, branching, with elaters.— 
Marchantia, Conocephalus. 
Order JUNGERMANNIALES. Scale Mosses. Sporophyte 
stalked, four-valved; with elaters. 
Family 5. Metzgeriaceae. Gametophyte usually 
thallose, archegones lateral.—Metz- 
geria, Pellia, Fossombronia. 
Family 6. Jungermanniaceae. Gametophyte a bi- 
lateral leafy stem, archegones termi- 
nal.—Lophosia, Bazzania, Scapania, 
Frullania. 
Class 19. MUSCI. Mosses. Gametophytes multilateral, usu- 
ally erect; sporophytes mostly dehis- 
cent by a circular lid, and without 
elaters. (Sp. about 12,600.) 
Order ANDREAEALES. Black Mosses. Sporophyte short- 
stalked, opening by four to six longi- 
tudinal slits. 
Family 7. Andreaeaceae. Small mosses.—Andreaea. 
Order SpHAGNALES. Peat Mosses. Sporophyte short- 
stalked, opening by a circular lid. 
Family 8. Sphagnaceae. Large bog mosses.—Sphag- 
num. 
Order Bryates. True Mosses. Sporophytes mostly long- 
stalked, generally opening by a circu- 
lar lid, usually with a peristome. 
Sub-order Acrocarpr. ‘Top Mosses.’” Sporophytes 
terminal on the main axis of the 
gametophyte. 
Family 9. Archidiaceae; 10, Dicranaceae (‘Turf 
Mosses”’) ; 11, Leucobryaceae (‘‘ Cush- 
