Difflugia Group 5

  1. Test > 140 µm.
  2. Test in cross section rounded.
  3. Test with rounded fundus.
  4. Pseudostome with smooth circular edge.
  5. Test narrow, W/L ratio 0.30-0.65

1

Length of Test > 300 µm  

2

1′

Length < 300 µm  

6

2

Test balloon-shaped, with long distinct neck

3

2′

Test pyriform; with less distinct neck. Length of the test 340-480 microns

3

Neck tubular but widening like a trumpet towards the pseudostome. Test length 420 µm

3′

Neck tubular, with parallel sides. Length of the test 315-370 µm  

4

Test with well-defined collar

9

4′

Test without well-defined collar

9

5

Collar very broad, turning outwards; its collar practically equal to the maximum width of the test. 

5′

Collar relatively small, not turning outwards

6

Pseudostome > 20 µm

7

6′

Pseudostome small, 9-20 µm

7

Test more or less ovoid, not cylindrical

9

7′

Test cylindrical, finger-shaped; fundus slightly wider than pseudostome

8

8

Test finger-shaped with abruptly cutt-off pseudostome. W/L ratio ≈ 0.5.
Length 180-310 µm.

8′

Test cylindrical

9

Pseudostome smaller than half the diameter of the test

10

9′

Pseudostome about half the diameter of the test

10

Test more or less pyriform

12

10′

Test not pyriform

11

11

Test elongated ovoid. Length 66-77 µm.

11′

Test with more or less straight sides. Length 60-85 µm

12

Test always with a region of large mineral grains above the pseudostome. Length 60-88 µm 

12′

Test often irregular, without region with much larger particles above the pseudostome. Length 72-78 µm 

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