LAKE ASSOCIATIONS 343 



different habitats showed that the algal species clearly fall into two 

 main groups. 



no 



3- 



0??? 



2 



It 







Jd.R. /IjbT. Ju.ae Sc^t. Jan. Abr. Jane bc^t. Jan. A|3t. June Sejot. 



4r 



7??? 

 2 



1 

 



J — '•■ I 



OIC morgSLnic shore 



QjV ordd-ULc ^Kore 



Fig. 200. Distribution of diatoms on slides suspended at different depths at 

 different seasons of the year off two types of shore. (After God ward.) 



A. Those typical of the inner parts of reed swamps (organic shores). 



B. Those typical of other habitats: 



(i) Species more abundant in streams, 

 (ii) Species more abundant on inorganic stony shores, 

 (iii) Species more abundant in the outer parts of highly evolved 

 reed-swamp and throughout the less evolved reed swamp. 



