48 HANDBOOK OF BRITISH MOSSES. 



inner peristorae mostly with intermediate cilia ; stem mostly 

 cylindrical. 



Genus 8. Hypnum. Cilia distinct; stem mostly without 

 paraphylla; leaves even. 



Genus 9. Ptychodium. Cilia rudimentary ; paraphylla nu- 

 merous. 



Genus 10. Heterocladium. Leaves of stem and branches 

 heteromorphous ; paraphylla few ; upper reticulations narrow. 



Genus 11. Thuidium. Leaves of stem and branches hetero- 

 morphous ; paraphylla numerous ; upper reticulations rounded. 



Genus 12. Pseudoleskea. Intermediate cilia present or ab- 

 sent; paraphylla numerous ; reticulations oval-punctiform. 



ORDER VI. ISOTRECIL 



Sporangium erect ; fruitstalk elongated ; veil cucullate ; pc- 

 ristome single or double ; leaf-cells minute. 



Genus 13. Isothecium. Cilia of inner peristome more or less 

 imperfect; upper leaf-cells linear; secondary stems dendroid. 



Genus 14. Climacium. Cilia of inner peristome wanting; 

 veil large ; lid adherent to the columella ; habit dendroid. 



Genus 35. Cylindrothecium. Peristome not hygrometric, 

 inserted below the mouth of the sporangium ; inner peristome 

 of sixteen narrow darker teeth ; stem decumbent. 



Genus 16. Pylaisia. Inner peristome divided almost to 

 the base into sixteen teeth, bipartite or gaping at the keel ; 

 intermediate cilia very short ; leaf-cells narrow ; stem creeping. 



Genus 17. Homalothecium. Intermediate cilia none ; teeth 

 of outer peristome solid ; veil large, subpilose ; leaf-cells li- 

 near ; stem partly creeping, partly assurgent. 



Genus 18. Orthothecium. Intermediate cilia short or want- 

 ing ; teeth of peristome thin ; cells at base of leaves not 

 quadrate. 



