98 



PLATE V. 



Fig. 68. Hantzschia dubravicensis Grün. 



— 69. Hantzschia truncata sp. nov. 



— 70. Hantzschia forma abnormis. 



— 71. Nitzschia angustata (W. Sm.) Grün, forma. 

 — - 72. Nitzschia Jonssoni sp. nov. 



— 73. Nitzschia glaberrima sp. nov. 



— 74. Nitzschia mucronata sp. nov. 



— 75. Eunotia islandica sp. nov. 



— 76. Synedra rumpens Ktz. var. islandica var. nov. 



— 77. Synedra Ulna (Nitzsch) Ehr. f. arcuata. 



— 78. Fragilaria Bacillus sp. nov. 



— 79. Fragilaria mutabilis (W. Sm.) Grün. var. inflata var. nov. 



— 80. Fragilaria rhombica sp. nov. 



— 81. Fragilaria triundulata sp. nov. 



— 82. Fragilaria undata W. Sm. forma. 



— 83. Denticula islandica sp. nov. 



— 84. Melosira Stefanssoni sp. nov. 



