Compare Ulnaria capitata
Ulnaria ulna var. spathulifera has a central area and more gradually expanded valve margins, terminating in rostrate apices.
LM scalebar = 10 µm
Length Range
260-480 µm
260-480 µm
Width Range
8-9.5 µm
8-9.5 µm
Striae in 10 µm
9-11
9-11
Also compare to
Ulnaria ulna var. spathulifera
BioData Reference
Patrick and Reimer 1966 Pl 7 Fig 8