Biddulphia alternans (J.W. Bailey) Van Heurck

Taxon description :

Cells are triangular or rectangular in valve view.
A tripartite curved line can be seen in the centre of the valve face.
Three straight thickened lines (costae) separate the three valve
corners from the central region.
Within these triangular areas an area of smaller areolae,
forming a pseudocellus are present.
Three labiate processes are located on the valve face.
The internal part of the labiate process is a well developed stalked structure.
Cells occur solitary or in irregular chains with adjacent cells being connected
by mucous secretions via the pseudocelli.

Diameter: 36-45 µm

Distribution:  B. alternans is a common neritic species
                   in the North Sea and North Atlantic.

Description was obtained from the database in  PLANKTON*NET

http://planktonnet.awi.de/