In case you cant see the hallmark (its right next to the rabbits ear) here is a description:
Its a diamond with what looks like either a crown, or an S on top (top outsode of diamond). The inside of the diamond says the following:
Top of Diamond: "18", or perhaps "13".
Right corner of diamond: "H"
Bottom corner: "B" or maybe "8"
Centre of Diamond: "R"
Each portion of the diamond is divided (Top, sides, bottom), since the letter "R" is in a sort of box.
I have no idea who this maker could be, the closest thing I could find is this sites example of an Austro-Hungarian hallmark. Perhaps the top is in fact "13" and represents the silver's grade.
I hope someone can help me,
Thank you in advance,
Adam