Dec, 1913.] The Classification of Plants, XL 213 



II. Ganietophyte a frond with stem and scales, or if fiat 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 tenninating 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. 

 Metzgeriaceffi. 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. Jungemianniaceffi. 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 Bryales 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, Archidiacese. 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. 



EropodiacccC, Eustichiaccce, Entodontacese, Fabroniaceffi, 

 Hedwegiacese, Fontinalacese, Climaciaceas, Cryph^aceae, 

 Leucodontaccce, Prionodontaceae, Crytopodace^, 

 Echinodiaceae, Ptychomniacese, Spiridentaccce, 

 LepyrodontaccEC, Pleurophascacese, Neckeracese, 

 Lembophyllacese, Pilotrichacese, Hookeriaceae, 

 Ephemeropsaceae, Hypopterygiaceae, Helicophyllaceas, 

 Rhacopilaceae, Leskeaceae, Hypnaceae, Leucomiaccce, 

 Brachytheciaceae, Sematophyllacese, Rhegmatodontaceag, 

 Hypnodendraceae. 



