Three views of the same specimen of the desmid
Staurastrum tohopekaligense var. trifurcatum  W. & G.S. West  1912

Quadrangular form from Sutherland, Scotland collected by Alan Joyce, examined and photographed by the author in 1990. Length and breadth not including processes L- 42 µm. B- 32 µm. 'This variety like the type exhibits considerable variation, not all the apices of the processes are trifurcate’. (Carter)

The trifurcate processes can just be seen in the photographs on some of the apices, They could easily be seen under the microscope by focussing on an apex.
 

Face view	End view
Side view

All comments to the author W H Ells are welcomed.

Reference:-
Carter Nellie 1923   A Monograph of the British Desmidiaceæ  Vol. V. page 179.  (Vols. I - IV by W. & G.S. West).