The genera Cocconeis Ehrenberg and Amphicocconeis gen. nov.

1

For each taxus, are indicated :
- The lower and the higher observed lengths and in parentheses those indicated in the diagnoses.
- The abundance in the investigated area, expressed by the number of samples where the taxus was observed.
- The presence around the Ile de Groix (G+)  and around the Ile aux moutons (M+).
- The characteristics of the presented valves/frustules (from left to right).

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Cocconeis capensis (Cholnoky) Witkowsky stat. nov. : 1 rapheless valve.

Length : 18 µm (14-18 µm)
Abundance : 1 / 39
Presence : G+
Length : 18 µm
Width : 12 µm
8 striae / 10 µm
Cocconeis capensis

Cocconeis clandestina A. Schmidt : 3 rapheless valves.

Length : 15-24 µm (25-50 µm)
Abundance : 3 / 39
Presence : G+
Lengths : 16, 19, 24 µm
Widths : 11,8, 13,5, 18 µm
7,5, 7, 6-7 striae / 10 µm
Cocconeis clandestina

Cocconeis costata Gregory : 1 rapheless valve.

Length : 22 µm (12-40 µm)
Abundance : 1 / 39
Presence : G+
Length : 22 µm
Width : 13 µm
9-10 striae / 10 µm
Cocconeis costata


Cocconeis debesi Hustedt  = Amphicocconeis debesi (Hustedt) de Stefano comb. nov. : 3 rapheless valves.

Length : 25-37,5 µm (40-60 µm)
Abundance : 3 / 39
Presence : G+
Lengths : 33, 36, 37,5 µm
Widths : 19,5, 22, 23 µm
7, 7, 8 striae / 10 µm
Cocconeis debesi 


Cocconeis dirupta Gregory var. dirupta : 2 raphe valves and 2 rapheless valves.

Length : 15-27 µm (15-60 µm)
Abundance : 13 / 39
Presence : G+
Lengths raphe valves : 27, 27 µm.   Lengths rapheless valves : 18,5, 23 µm.
Widths raphe valves : 17, 15 µm.    Widths rapheless valves : 11, 13 µm.
Raphe valves : 22, 24 striae / 10 µm.   Rapheless valves : 22-23, 25 transapical striae / 10 µm ; 15, 15  longitudinal ribs / 10 µm.
Cocconeis dirupta

Cocconeis discrepans A. Schmidt : 3 rapheless valves.

Length : 9-17 µm (12-19 µm)
Abundance : 11 / 39
Presence : G+
Lengths : 13,5, 16, 17 µm
Widths : 6,5, 8, 6 µm
12, 12, 12-13 stries / 10 µm
Cocconeis discrepans

Cocconeis disculoides Hustedt = Amphicocconeis disculoides (Hustedt) comb. nov. : 2 rapheless valves.

Length : 13-27 µm (18-30 µm)
Abundance : 11 / 39
Presence : G+, M+
Lengths : 22, 27 µm
Widths : 12, 16 µm
7,5, 8 striae / 10 µm
Cocconeis disculoides

Cocconeis fluminensis (Grunow) Peragallo : 2 rapheless valves.

Length : 20-36,5 µm (25-60 µm)
Abundance : 7 / 39
Presence : G+, M+
Lengths : 28, 36,5 µm
Widths : 18, 23 µm
11, 11 striae / 10 µm
Cocconeis fluminensis

Cocconeis fluminensis var. subimpletus Peragallo : 1 rapheless valve.

Length : 33-36 µm (? µm)
Abundance : 3 / 39
Presence : G+
Length : 36 µm
Width : 21 µm
9 striae / 10 µm
Cocconeis fluminensis var subimpletus

Cocconeis grata A. Schmidt : 1 raphe valve and 3 rapheless valves.

Length : 27-39 µm (40-60 µm)
Abundance : 4 / 39
Presence : G+, M+
Lengths : 33, 33, 30, 36 µm
Widths : 21, 21, 22, 24 µm
Raphe valve : 15 striae / 10 µm. Rapheless valves : 11, 9, 11 striae / 10 µm
Cocconeis grata

Cocconeis guttata Hustedt, in Aleem & Hustedt : 2 frustules  and 2 rapheless valves (?).

Length : 14-28 µm (15-30 µm)
Abundance : 11 / 39
Presence : G+, M+
Lengths : 16, 21, 21,5, 22 µm
Widths : 9,5, 13,7, 14, 15 µm
8, 7, 8, 9 striae / 10 µm
Cocconeis guttata

Cocconeis molesta var. crucifera Grunow : 4 frustules and 2 rapheless valves.

Length : 10-17 µm (15-30 µm)
Abundance : 17 / 39
Presence : G+, M+
Lengths frustules : 14, 16, 17, 19 µm.   Lengths rapheless valves : 13,7, 20 µm.
Widths frustules : 11, 12, 12, 13,5 µm.   Widths rapheless valves : 10,3, 12 µm.
Frustules :  30 transapical striae / 10 µm ; 21  longitudinal ribs / 10 µm.    Rapheless valves : 18, 21 longitudinal ribs / 10 µm.
Cocconeis molesta

Cocconeis nummularia (Greville) Peragallo : 1 rapheless valve.

Length : 26-29 µm (23-45 µm)
Abundance : 1 / 39
Presence : G+
Length : 29 µm
Widthr : 20 µm
11-12 striae / 10 µm
Cocconeis nummularia

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