48 HANDBOOK OF BRITISH MOSSES. 



inner peristome mostly with intermediate cilia ; stem mostly 

 cylindrical. 



Genus 8. Rypnum. — 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. 



Oeder VI. ISOTREOII. 



Sporangium erect ; fruitstalk elongated ; veil cucullate ; pe- 

 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 15. 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. 



