"But I am suspicious until I recognize our helmets"
German Soldier at the Battle of the Somme, 1916
Creative Commons Attribution Share AlikeGerman Soldier at the Battle of the Somme, 1916 - Credit: Bundesarchiv, Bild 183-R05148

The German M1918 helmet (which they were most likely wearing) had a unique, steep round shape with a prominent bill.  View a picture