58 Mr. W. Mitten's Remarks on Mosses. 



Tribe IX. HypNACJSiE. 



Cells of the leaves prosenchymatous, but mostly a few quadrate 

 coloured ones at the base of the leaf. Capsules gymnostouiate, 

 peristomate, and diploperistomate. Teeth sixteen : internal pe- 

 ristome of processes and cilia. Calyptra mitriform, dimidiate, 

 or calymperoid. Small or large mosses with simple or much 

 branched stems, and nerveless or one or more nerved leaves : 

 growing on the earth, on rocks, or on trees. 



Genus 1. Rhegmatodon, Brid. 



2. Fabronia, Raddi. 



3. Neckera, Hediv. 



4. Aulacopilum, Wils. 



5. ? Wardia, Harvey, 



6. Phyllogonium, Brid. 



7. Pilotrichum, Pal. de Beauv. 



8. Hookeria, Smith. 



9. Hypnum, Dill. 



Tribe X. PoLYTRICHACEiE. 



Cells of the leaves parenchymatous, firm. Capsules stomate 

 and peristomate. Peristome of numerous inarticulate cilia, free 

 or combined together, and forming short tooth-like processes 

 which are more or less adherent to the tympaniform expansion of 

 the columella at the mouth of the capsule. Calyptra dimidiate. 

 Small or very large mosses, mostly with rigid acute leaves, large, 

 more or less angular, asymmetric capsules, and calyptras mostly 

 covered with hair : growing on the earth. 



Genus 1. Lyellia, R. Brown. 



2. Polytrichum, Dill. 



3. Dawsonia, R. Brown. 



Tribe XI. Buxbaumiace^. 



Cells of the leaves partly parenchymatous and partly prosen- 

 chymatous. Capsules asymmetric, peristomate and diploperisto- 

 mate. Teeth beaded, free, or coherent together : internal pe- 

 ristome of a plicate membrane. Small but remarkable mosses, 

 with very large asymmetric capsules : growing on the earth, on 

 rocks, or on trees. 



Genus 1. Diphyscium, Web. et Mohr. 



2. Buxbaumia, Haller. 



Tribe XII. Leucobryace^. 



Cells of the leaves in one or more layers, dimorphous, external 

 partly parenchymatous and partly prosenchymatous, foraminose 

 on the internal walls, colourless ; internal cells placed between 



