Visit us at

Diatoms of the United States is now known as Diatoms of North America.
This site has been redesigned and updated, and will be closing soon.





Silica flap or porous plate covering an areola.

In a loculate areola, may form the external or internal wall, depending on species, opposite the foramen. Plural form is vela.

Two types of vela are cribra and volae.


Round, F.E., Crawford, R.M. and Mann, D.G. (1990). The Diatoms. Biology and Morphology of the Genera. Cambridge University Press, Cambridge, 747 pp.