Pinnularia globiceps v. krockii (Grunow)
Pinnularia globiceps v. krockii (Grunow) 1891, p. 30(Krammer 1992b).
This image was taken with an additional 40% magnification.
This image was taken with the additional magnification and utilizing DIC.
This description is taken from what Krammer calls Pinnularia krookii. Outline linear with distinctly triundulate sides. Middle swelling is slightly broader than the swelling at the poles. Ends are capitate, bluntly rounded. Strongly variable, thin to broad, widened at axial area. Area often asymmetrical, almost to the margin of the valve. Raphe philiform and straight, not bent in middle. Central nodule distinct. Shape of ends of raphe hardly visible under a light microscope(Krammer 1992b).
Navicula krockii Grunow 1882, p 155, fig. 30:40 (zur Schreibung des Namens siehe unten)(Krammer 1992b).
Navicula ignobilis Krasske 1938(Krammer 1992b).
Pinnularia ignobilis (Krasske) Cleve-Euler 1955(Krammer 1992b).
Northern alpine regions, in fossil deposits, usually rare in their environment. Found in electolyte poor and oxygen rich waters(Krammer 1992b; Beaver 1981).
Length is 19 to 28 micrometers (Krammer 1992b).
Width is 5.5 to 7 micrometers (Krammer 1992b).
Striae are 15 to 17 in 10 micrometers (Krammer 1992b).