Home
Practitioners
Morphology
All Morphological Groups
Centric
Araphid
Eunotioid
Symmetric Biraphid
Monoraphid
Asymmetric Biraphid
Epithemioid
Nitzschioid
Surirelloid
Genera
Species
Glossary
About Us
About
News
Projects
Review Board
Taxon Contributors
Contact Us
What are diatoms?
Search
×
Diatoms of North America
Practitioners
Morphology
Centric
Araphid
Eunotioid
Symmetric Biraphid
Monoraphid
Asymmetric Biraphid
Epithemioid
Nitzschioid
Surirelloid
Genera
Species
Glossary
About Us
News
Projects
Review Board
Taxon Contributors
Contact Us
What are diatoms?
Search taxa, citations, glossary, contributors, and images
Submit
Close search
GS020021_19.jpg
Glossary Term
Porca
|
Keel
Caption
External surface of
Surirella amphioxys
(SEM). The raised portion of the undulation is a porca. The raised canal (keel) containing the raphe is at the top of the image.
Credit
Marina Potapova
