Dorsal

The side of the valve that is the wider and more convex of the two sides. Occurs in genera that are asymmetrical to the apical axis, such as Cymbella and Encyonema. From Latin for back of the body.

Encyonema Dorsal Margin
Image Credit: Sarah Spaulding
The arrow indicates the dorsal margin of Encyonema
Reimeria Dorsal Stigma
Image Credit: Marina Potapova
The arrow indicates the dorsal stigma of Reimeria