Corythium dubium
Corythion dubium
Corythium dubium, 35 µm

 

 

Corythion dubium Taranek, 1871

 

Diagnosis: shell ovoid, composed of approximately four hundred oval shell-plates, irreguularly arranged, very small and usually overlapping each other; aperture sub-terminal, oval and invaginated; about thirty small, oval, apertural-plates surround the aperture, each carrying a median dorsal tooth.

 

Dimensions: Length 33-43 µm; breadth 25; mouth 10 µm; shell-plates length 2.9-3.4, width 1.5-1.9; diameter of apertural-plates 0.9-1.1 µm.

 

Ecology: Sphagnum and mosses.

 

Remarks: The apertural-plates are similar to those seen in Trinema enchelys and T. lineare. Differences in the size of the shell are illustrated by Cash et al., (1915).

 

Corythion dubium
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 is 56 µm and represents the population to the right.
Corythion dubium, 39 µm
Corythium dubium
Corythion dubium, with small scales visible
Corythium dubium
Corythion dubium, 35 µm, nucleus visible
Corythium dubium
Corythion dubium
Left: Shell 37 µm, in moss on a roof; Right: from Ogden, 1980