Sminnoch, are you suggesting that because of the appearance of a rim? Yes, now that I look at it, that bothers me also.
Here's another image of a coin labeled: Ptolemaic Kings of Egypt
Ptolemy II Philadelphos (285-246 B.C.) Bronze Weight 5.4g. Diameter 18 mm.
Obverse: Diademed and horned bust of Ptolemy I Soter as Zeus Ammon right. Reverse: ΒΑΣΙΛΕΩΣ
ΠΤΟΛΕΜΑΙΟΥ, eagle standing left on thunderbolt. Nice brick-red patina.