(Hust.) Bukht. and Round 1996
Psammothidium lauenburgianum has a rimmed depression on the rapheless valve like many species of Planothidium. It is most likely to be confused with Planothidium lanceolatum, but can be distinguished from it by considerably higher stria density.
(Bréb. ex Kütz.) Lange-Bert. 1999