ISO 



MUSCINEjE 



Order 2. — Phascace^. 



In the small order of Phascace^e the roundish sporange dehisces 

 neither by the detachment of an opercule nor by longitudinal slits, but 

 decays to allow of the escape of the spores ; the calypter is ruptured 

 laterally without being raised up as a cap ; the columel is sometimes 

 wanting. According to Leitgeb, 

 Archidium (Brid.) resembles the 

 Hepatic£e more closely than the 

 Bryaceas in the processes which 

 lead to the formation of the 

 spores, especially in the differ- 

 entiation of the archespore into 

 spore-mother-cells which are 



Fig. 121. — Ephejueru'n se-rratutn Hampe ; 

 mature plant with persistent protoneme 

 (magnified). (After Luerssen.) 



Fig. 122. — Plettridhivi sitbulatuni Rabenh. 

 sporange (magnified). (After Luerssen. 



irregularly interspersed among cells that remain sterile. The spore- 

 mother-cells do not number more than from one to seven in each spo- 

 range ; in each of them four spores are formed tetrahedrally. 



The Phascaceae are caespitose in their habit ; the protoneme persists 

 until the maturity of the sporogone. Principal genera : — Phascum (L.), 

 Archidium (Brid.), Ephemerum (Hpe.), Pleuridium (Brid.). 



Literature. 



Leitgeb— Sitzber. Akad. AViss. Wien, i88o, p. 447. 

 Miiller— Pringsheim's Jahrb. wiss. Bot., 1867, p. 237. 



Order 3. — Andre^eace^e. 



The Andreaeaceas constitute a small order of mosses, comprising the 

 single genus Andreaea (Ehrh.), characterised by the absence of an oper- 

 cule to the sporange, which opens by four, or very rarely eight, longi- 

 tudinal slits, not reaching either to the base or the apex of the capsule. 



