Thread-moss 



Apex of leaf. 



Portion of peristome 

 with three outer teeth, 

 four inner and groups 

 of cilia. 



Empty 

 spore- 

 case. 



Inner peri- 

 gonial leaf 

 w ith an- 

 ther idi a 

 and para- 

 physes. 



Lid. 



Spore-case 

 with lid. 



M. affine. 



Mnium hornum, Linn. 



Habit and habitat. Robust in dense tufts, on damp earth in 

 woods, about the roots of trees, and on rocks. 



Name. The specific name, hornum, probably refers to the 

 horny border. 



Plant (gametophyte).The young plants are bright-green, the 

 older are dark-green; stems, i to 2 inches high, simple erect; 

 sterile shoots, erect from the base. 



Leaves. The lowest minute, the upper gradually increasing 

 in size, the terminal forming a rosette, all oblong-lance-shaped, 



apex more or less acute with a 

 sharp little point; base growing 

 slightly down the stem ; margin 

 with a strong red border, spiny 

 toothed from below the middle, 

 the teeth in a double row ; vein 



Spore-case without lid. 



Plant with 

 sporophyte. 



Leaves. 



M. hornum. 



231 



Spiny margin; 

 the spines in a 

 double row. 



