Stephanodiscus hantzschii has a lower areola density, more heavily silicified valves, and an annulus may be present or absent. Stephanodiscus binderanus has smaller valves and a higher density of fascicles. Stephanodiscus parvus has a lower areola density and a prominent central fultoportula. Cyclostephanos invisitatus has finer areolae and a higher density of fascicles.

LM scalebar = 10 µm
Stephanodiscus hantzschii f tenuis LM3 Stephanodiscus hantzschii f tenuis LM7 Stephanodiscus hantzschii f tenuis LM2 Stephanodiscus hantzschii f tenuis LM6 Stephanodiscus hantzschii f tenuis LM1 Stephanodiscus hantzschii f tenuis LM4 Stephanodiscus hantzschii f tenuis LM5
15.5-19 µm
Striae in 10 µm
5.7-7.5 based on circumferential density

Cyclostephanos invisitatus

(M.H.Hohn and Hellermann) E.C.Ther., Stoermer and Håk. 1998

Cyinvisitatus 1 Cyinvistatus 2 Cyinvisitatus 3 Cyinvisitatus 4A Cyinvisitatus 5 Cyinvisitatus 6
7.8-15.1 µm
Striae in 10 µm
15-16 based on chord count, 12-15 based on circumferential density

Stephanodiscus hantzschii

Grunow in Cleve and Grunow 1880

Stephanodiscus hantzschii LM7 Stephanodiscus hantzschii LM4 Stephanodiscus hantzschii LM3 Stephanodiscus hantzschii LM6 Stephanodiscus hantzschii LM1
11.8-20.3 µm
Striae in 10 µm
6-9 fascicles based on circumferential count

Stephanodiscus binderanus

(Kütz.) Krieger 1927

Stephanodiscus binderanus LM7 Stephanodiscus binderanus LM6 Stephanodiscus binderanus LM5 Stephanodiscus binderanus LM4 Stephanodiscus binderanus LM1 Stephanodiscus binderanus LM2 Stephanodiscus binderanus LM3
6.3-11.8 µm
Width Range
2.6-4.7 µm
Striae in 10 µm
10 to 15 based on circumferential density

Stephanodiscus parvus

Stoermer and Håk. 1984

Stephanodiscus parvus LM7 Stephanodiscus parvus LM6 Stephanodiscus parvus LM5 Stephanodiscus parvus LM4 Stephanodiscus parvus LM2 Stephanodiscus parvus LM1
4.3-9.5 µm
Striae in 10 µm
8-12 based on circumferential count