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Prestauroneis protracta valves are linear to linear-lanceolate with rostrate, rounded apices. Navicula genovefae is smaller length and breadth, and the central striae are more coarse.

LM scalebar = 10 µm
Prestauroneis integra LM10 Prestauroneis integra LM6 Prestauroneis integra LM2 Prestauroneis integra LM5 Prestauroneis integra LM4
Length Range
26.6-43.0 µm
Width Range
9.3-12.6 µm
Striae in 10 µm
9.9-15 at center of the valve, 15.7-20.8 near the apices

Prestauroneis protracta

(Grunow) I.W.Bishop, Minerovic, Q.Liu and Kociolek 2017

Prestauroneis protracta LM3 Prestauroneis protracta LM6 Prestauroneis protracta LM4 Prestauroneis protracta LM7 Prestauroneis protracta LM5 Prestauroneis protracta LM2 Prestauroneis protracta LM1
Length Range
26.0-32.8 µm
Width Range
6.5-7.6 µm
Striae in 10 µm
18-22

Navicula genovefae

Fusey 1951

Navicula genovefae LM5 Navicula genovefae LM6 Navicula genovefae LM2 Navicula genovefae LM3 Navicula genovefae LM4 Navicula genovefae LM7 Navicula genovefae LM1
Length Range
18.8-25.1 µm
Width Range
5.5-5.9 µm
Striae in 10 µm
14-16 at midvalve; 19-21 toward the apices