Compare Frustulia inculta
Compare
Frustulia inculta is generally much smaller, has a higher stria density and the striae are more parallel than F. krammeri. Frustulia inculta lacks the robust porte-crayon structure and grouping of poroids in the external central area of F. rexii. Frustulia amphipleuroides has striae that circumradiate the poles and the central nodule is elongate. The valves of F. inculta have less undulate margins and much less protracted apices than F. crassinervia. F. inculta has less dense striae than F. crassinervia. F. inculta has less noticeably undulate margins and protracted apices than F. quadrisinuata. F. inculta has striae that do not radiate the apices while F. saxonica has striae that do radiate the apices. The helictoglossae in F. inculta are longer than those in F. saxonica, giving the porte-crayon a larger appearance.
LM scalebar = 10 µm
Length Range
54-74 µm
54-74 µm
Width Range
11.5-14.0 µm
11.5-14.0 µm
Striae in 10 µm
28-30 in the center valve, 27-28 at the ends
28-30 in the center valve, 27-28 at the ends
Frustulia krammeri
Length Range
68-119 µm
68-119 µm
Width Range
18-22 µm
18-22 µm
Striae in 10 µm
24-26 in the center, 24-25 at the ends
24-26 in the center, 24-25 at the ends
Frustulia rexii
Length Range
68-111 µm
68-111 µm
Width Range
17.5-21.0 µm
17.5-21.0 µm
Striae in 10 µm
26–28 in the center, 28 at the ends
26–28 in the center, 28 at the ends
Frustulia amphipleuroides
Length Range
63.0-97.0 µm
63.0-97.0 µm
Width Range
15.0-16.5 µm
15.0-16.5 µm
Striae in 10 µm
23-25 in the center, 25-26 at the ends
23-25 in the center, 25-26 at the ends
Frustulia crassinervia
Length Range
34.5-48.0 µm
34.5-48.0 µm
Width Range
9.0-10.5 µm
9.0-10.5 µm
Striae in 10 µm
33-35 in the center
33-35 in the center
