Frickea can be distinguished from Frustulia by its very long, rib-like helictoglossa, longitudinal ribs that extend to but do not fuse with the helictoglossa, and the large T-shape of all four external raphe endings.

LM scalebar = 10 µm
Length Range
255.0-265.0 µm
Width Range
45.0 µm
Striae in 10 µm
22-24
Frickea lewisiana LM5
Frickea lewisiana LM3
Frickea lewisiana LM1
Frickea lewisiana LM4
Frickea lewisiana LM2
Frickea lewisiana LM5 Frickea lewisiana LM3 Frickea lewisiana LM1 Frickea lewisiana LM4 Frickea lewisiana LM2

Also compare to

Frustulia

Rabenh.