291 



In the table on p. 263 an account is given of the occurrence 

 of the "characterising" freshwater-forms to a certain extent over 

 the tvhole country, but without reference to their distribution accord- 

 ing to the habitats '■'■running teater,^'' '■'■moors and moorland ditches''' 

 and Hakes and stagnant watery 



Especially markedly "characterising" forms contributing 8 ^/o 

 and upwards are, therefore, for the tvhole country, forms of the 

 genera Gomphonema (21 ^lo), Synedra (IS^Io), Achnanthes (15 ^/o), 

 Epithemia and Fragilaria (each to the extent of 13 ^/o), Meridion 

 (11 ^/o), Melosira (10 ^/o), Navicula and Cymbella (each to the ex- 

 tent of 8 ^lo). The rest with less than 5 "/o. 



I have, moreover, in the table on p, 265 given an account of 

 the characterising coast forms among the Danish Diatoms. From 

 this table it will be seen that 



Most prominent for the whole country (to the extent of above 

 11 ^/o) are forms of the genera Synedra (25 ^lo), Navicula (17 ^/o), 

 Cocconeis (13*^/0), Melosira (12 ''/o) and Achnanthes (11 **/o). 



More common along the coast of Zealand than that of Jut- 

 land are forms of the genera Achnanthes, Cocconeis, Epithemia, 

 Licmophora, Melosira, Nitzschia and Synedra. 



Among these, more markedly, Synedra (to the extent of 30 ^/o 

 in Z. as against 20 ^/o in J.), Achnanthes (16 ^/o as against 8 ^/o), 

 Melosira (19 °/o as against 11 ''/o), and the rest with a difference 

 in percentage of 3. 



Only in Z. : Grammatophora (4 ^la), Hyalodiscus (3 ^/o) and 

 Surirella (2^/0). 



More common in J. than Z. are Amphipleura, Amphora, Di- 

 atoma, Grunowiella, Mastogloia and Navicula. 



Among these, more markedly, Navicula (to the extent of 39 "/o 

 in J. as against 14 *^/o in Z. ^), Amphipleura rutilans (11 "/o in J. 

 as against 2 ^/o), Maslogloia (8 *^/o in J. as against 1 ^/o), and the 

 rest with a difference in percentage of 3. 



Only in J : Schizonema (9 °/o), Fragilaria (5 ^/o), Stauroneis 



The reason for the great predominance of Navicula will be found 

 in the "sand-samples" from the coasts of Jutland, in which the 

 small "sand-form" of Navicula cincfa is often very conspicuous by 

 the numbers which occur. 



19« 



