Dec , 1913.] 
The Classification of Plants, XI. 
213. 
II. Gametophyte a frond with stem and scales, or if flat and 
thalloid not composed of several distinct tissue layers, 
never with air passages; sporophyte consisting of foot, 
stalk and sporangium, nearly always opening by 4 
valves. Jungermanniales. 
1. Archegonia not terminating the growth of the axis on 
which they are borne; perigonium not consisting of 
distinct scales but of a continuous sheath; frond 
without scales or with imperfectly developed scales. 
Metzgeriaceae. Metzgeria, Pallavicinia, Pellia, 
Fossombronia, etc. 
2. Archegonia terminating the growth of the axis; 
perigonium consisting of scales or occasionally 
wanting; frond nearly always with 2 or 3 rows of 
scales. Jungermanniaceae. Nardia, Lophozia, 
Kantia, Porella, Frullania, etc. 
SYNOPSIS OF THE ODRERS AND MAIN FAMILY GROUPS OF MUSCI. 
At present, only a partial segregation of the families of Hypna- 
les and Brvales is attempted. 
A. Sporangium without a columella, the sporogenous and vegeta¬ 
tive cells commingled; spores very large; archegonium 
not forming a calyptra but finally rupturing irregularly. 
Archidiales, Archidiaceae. Archidium. 
B. Sporangium with a definite central columella. 
I. Archegonia situated on top of short, special lateral 
branches; peristome when present usually double, develop¬ 
ed in the amphithecium from thickened parts of the cell 
walls; teeth transversely barred, the outer set usually 
16, alternating with the inner; frond usually of creeping 
habit. Hypnales. 
Eropodiaceae, Eustichiaceae, Entodontaceae, Fabroniaceae, 
Hedwegiaceae, Fontinalaceae, Climaciaceae, Cryphaeaceae, 
Lcucodontaceae, Prionodontaceae, Crvtopodaceae, 
Eehinodiaceae, Ptychomniaceae, Spiridentaceae, 
Lepyrodontaceae, Pleurophascaceae, Neckeraceae, 
Lembophyllaceae, Pilotrichaceae, Hookeriaceae, 
Ephemeropsaceae, Hypopterygiaceae, Helicophvllaceae, 
Rhacopilaceae, Leskeaceae, Hvpnaceae, Leucomiaceae, 
Brachytheciaceae, Sematophyllaceae, Rhegmatodontaceae, 
Hvpnodendraceae. 
