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Diatoms of the United States is now known as Diatoms of North America.
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Cleve ex Meister 1912      Category: Monoraphid
TYPE SPECIES: Eucocconeis flexella (Kützing) Meister




Image Credit: Marina Potapova, Eduardo Morales

CLASS: Bacillariophycideae
  ORDER: Achnanthales
    FAMILY: Achnanthidiaceae

  1. Frustules heterovalvar - one valve with a raphe, the other lacking a raphe
  2. Frustules with torsional twist about the apical axis
  3. Valves linear-elliptic to lanceolate
  4. Striae uniseriate
  5. Terminal raphe fissures long, curved to opposite sides

Eucconeis frustules are bent about the median transapical plane, including a twisted, sigmoid central sternum. As a member of the monoraphid group, the frustules are heterovalvar and differ in ornamentation between the raphe valve and rapheless valve.

Eucocconeis species occur commonly in the littoral zone of oligotrophic lakes, within epipelic, epipsammic, or epilithic habitats. Some species occur on wet walls.

Cite This Page:
Potapova, M., Spaulding, S., and Edlund, M. (2008). Eucocconeis. In Diatoms of the United States. Retrieved May 20, 2018, from

Contributor: Marina Potapova | Sarah Spaulding | Mark Edlund - December 2008
Reviewer: Sam Rushforth - May 2010