Mosses and Lichens 



Lid (operculum). Flattened with an acute point at the centre. 

 Teeth (peristome). Sixty-four, blunt at the apex, continuous 

 at the base. United at the tips with a thin disk (epiphragm). 

 Spores. Red-brown, ripe in summer. 

 Distribution. Universal. 



Too* 



Lid. 



Portion of peristome. 



P. commune. 



Summit of spore-case with 64 

 teeth around the thin disk. 



Genus DIPHYSCIUM, Mohr 



The species of the Genus Diphyscium are minute stemless 

 plants growing scattered on the ground and on rocks. The leaves 

 are strap-shaped or lance- 

 shaped with a vein. The 

 cells are a to 3 layers 

 deep. The leaves at the 

 base of the spore-cases 

 are large, saw-toothed 

 or cut into a ragged 



fri n ere ' il* SMm - Growing on the ground. 



The spore-cases are immersed or exserted on an 

 inconspicuous pedicel, they are oval and taper-pointed, 

 oblique and swollen on one side, with a conical lid. 

 The outer teeth are none, or rudimentary and the 

 inner membrane forms a pale blunt cone of 16 

 twisted folds. 



The name, from Sk, twice, and <f>vatctov, a vesicle, 

 refers to the double wall of the spore case, which is 

 due to the spore-sac being widely separated from the outer wall. 

 There are eleven species known in all, one of them being 

 found in North America. 



258 



D. folum, 



