6 MUSCI. 



b. 

 Seta lateral. 



# 



Peristome single. 



28. Pterogonium. Peristome of 16 entire equidistant teeth, 

 Calyptra dimidiate. 



29. Leucodon. Peristome of 32 teeth united in pairs. 

 Calyptra dimidiate. 



* * 



Peristome double. 



A. 



Inner peristome composed of free cilia. 



30. Neckera. Outer peristome of 16 teeth ; inner of 16 cilia, 

 sometimes connected below by a very short membrane. Calyp- 

 tra dimidiate. 



31. Anomodon. Outer peristome of 16 teeth; inner of 16 

 cilia from between the teeth. Calyptra dimidiate. 



32. Daltonia. Outer peristome of 16 teeth ; inner of 16 

 cilia from between the teeth. Calyptra campanulate. 



B. 



Inner peristome of cilia united below by a membrane or by trans- 

 verse processes. 



33. Fontinalis. Outer peristome of 16 teeth; inner of 16 

 cilia connected by transverse processes into a cone. Calyptra 

 campanulate. 



34. Hookekia. Outer peristome of 16 teeth ; inner of 16 

 cilia united below into a membrane. Calyptra campanulate. 



35. Hypnum. Outer persitome of 16 teeth; inner of 16 cilia 

 united below by a membrane, and having filiform processes fre- 

 quently interposed. Catyptra dimidiate. 



