M060618a
Oval containing a bird flying from right to left, all above "GERMANY".
A few sources claim that this is a lesser-known version of the mark used by Hermann Ohme from Niedersalzbrunn. Firstly, it is not shown or mentioned in any reputable mark reference book. Furthermore, the blue mark shown in the second image is definitely that of the manufacturer Porzellanfabrik Rudolstadt Straus & Söhne AG from Rudolstadt in Thuringia.
M060618a
Oval containing a bird flying from right to left, all above "GERMANY".
M060618b
Same as before but with manufacturer mark of Strauss & Söhne from Rudolstadt (Thuringia).