![Corythium dubium](/wp-content/images/Corythion-dubium-mos-KA-68-um.webp)
![Corythion dubium](/wp-content/images/Corythion-dubium-AM-54-um042.webp)
C. constricta, 68 and 55 µm
Corythion constricta (Certes, 1889) Jung, 1942
Diagnosis: As for C. dubium, but much larger (>45 µm) and with well developed pseudostomal border.
Dimensions: Jung (1942): Length 68-74 µm; breadth 50-56 µm; Vucetich, 1975: 79-83 µm; my measurements length 49-72 µm (see table below).
Ecology: Sphagnum and mosses.
![Corythion dubium](/wp-content/images/grafiek-corythion-dubium.webp)
Morphometry of Corythion dubium in one sample from a Sphagnum bog in Amersfoort, the Netherlands. Three groups can be distinguished. The left shell represents the middle group and is 35 µm long, the other shell, possibly C. constricta, is 56 µm and represents the population to the right.
![](/wp-content/images/Corythion-dubium-AM-72-um-each.webp)
Corythion cf constricta, each shell 72 µm
![Corythium dubium](/wp-content/images/Corythion-dubium-AM-72-um.webp)
Corythion cf constricta 72 µm
![Corythium constricta](/wp-content/images/Corythion-constricta-02.webp)
C. constricta a-b: after Jung (1942); d: after Vucetich (1975)