A Key to the More Frequently Occurring Freshwater Algae - Freshwater Algae: Identification, Enumeration and Use as Bioindicators - page 158

1a

1b

1c

2a

2b

2c

3

4b

4a

5

6b

7a

6a

7b

Plate V 1 . Diatoma :(a) D. vulgaris girdle view, (b) D. vulgaris valve view, (c) D. anceps valve view. 2. Spirogyra :(a)
S. protecta ,(b) S. circumlineata , (with zygospore) (c) S. wrightiana . 3. Geminella. 4. Spondylosium :(a) S. planum, (b) S.
rectangulare . 5. Stichococcus. 6. Microspora : (a) M. crassior, (b) M. floccosa. 7. Tribonema :(a) T. viride ,(b) T. minus.