289 



Among these, more markedly, Achnanthes (to the extent of 

 24 "/o in Z. as against 8 °/o in J.), Gomphonema (28 ^/o as against 

 14 o/o), Meridian (18 ^/o as against 12 ^/o), Surirella (10 •'/o as 

 against 6 ^/o), Synedra (28 "/o as against 22 ''/o), and the rest with 

 a difference in percentage of less than 3. 



Only in Z.: Stephanodiscus (3 ^lo), Amphora (2 ^/o), Rhoicos- 

 phenia (1 ^/o). 



More common in J. than Z. are forms of the genera Anomoe- 

 oneis, Cocconeis, Cyclotella, Diatotna, Epithemia, Fragilaria, 

 Melosira, Navictila. 



Among these, more markedly, Melosira (to the extent of 1 7 ^/o 

 in J. as against 8 "/o in Z.), Epithemia (8 ^/o as against 2 ^lo), 

 Cocconeis (12 ^lo as against 7 ^/o), Navicula (15 "/o as against 

 10 ^''o), and the rest with a difference in percentage of less than 2. 



Only in J. : Tabellaria (7 *^/o), Eunotia (3 ^lo), Frustulia and 

 Hantzschia (each to the extent of 1 ^/o). 



About as common in Z. as J. are Cymbella (6 "/o) and Piw- 

 nularia (3 "/o). 



Genera which do not contain forms "characterising" for "rwn- 

 ning water^'' either in ^. or in J. are Amphipletira, Asterionella 

 and Mastogloia. 



From '■Wunning water^^ it is, consequently, especially forms of 

 the genera Achnanthes and Gomphonema which are "characterising" 

 in Zealand, and of the genera Melosira and Tabellaria which are 

 ^'characterising" in Jutland. 



The table on p. 259 demonstrates the foUowing facts : — 



More common in Zealand than Jutland, from '■'■moors and 

 moorland ditches,^'' are forms of the genera Cymbella, Fragilaria, 

 Gomphonema, Navicula, Pinnularia and Tabellaria. 



Among these, more markedly, Gomphonema (to the extent of 

 290/0 in Z. as against 14^/0 in J.), Cymbella (9 "/o as against 

 2 o/o), Fragilaria (11 ^/o as against 5^/0), Pinnularia (8 "/o as 

 against 2 0/0), and the rest with a difference in percentage of less 

 than 2. 



Only in Z.: Cocconeis (ll°/o), Amphora (4^/0), Mastogloia 

 (3 O/o), Amphipleura, Cyclotella, Hantzschia and Surirella (each 

 to the extent of 1 0/0). 



More common in J. than ^. are forms of the genera, Ach- 



19 



