Spaulding, S.,
Edlund, M.
(2008).
Cocconeis.
In Diatoms of North America.
Retrieved June 21, 2025, from https://diatoms.org/genera/cocconeis
Monoraphid
Cocconeis
Frustules heterovalvar - one valve with raphe, the other lacking raphe
Valves elliptic
Striae uniseriate (freshwater species)
Terminal raphe fissures absent
Cocconeis is heterovalvar; the raphe valve ornamentation differs from that of the rapheless valve. In fact, ornamentation of the raphe valve may differ markedly from that of the rapheless valve. The valve mantle is narrow in relation to the valve face, so cells are rarely (if ever) seen in girdle view.
Valves may be flexed, or arched,...