3^4 
MUSCINEM. 
form a membrane ; in this case the teeth appear split from one another above, and the 
endostome (the inner peristome) is composed of a lattice-work of longitudinal or trans- 
verse ridges instead of cilia (Fig. 267). A great variety is met with here, which may 
easily be understood by the beginner when he has obtained a clear idea of the principle. 
The inner and outer sides of the teeth of the peristome are hygroscopic to a different 
