The bottom one is a picture of athena. I have copied you a description of what you have though I am unsure as to their authenticity, and metal of composition. Getting them valued is important though. I can definitwely say that if they are genuine then the work on the puts them at the mid 5th century BC. Description to follow:
Athens, 467-465 BC. Silver Dekadrachm (43.38 g). Head of Athena right, wearing single-pendant earring, necklace, and crested Attic helmet decorated with three olive leaves over visor and a spiral palmette on the bowl / ΑΘΕ (ΑΘΗΝΑΙΩΝ - of Athenians), owl standing facing, wings spread; olive sprig and crescent to upper left; all within incuse square.
Best of luck and if they are real you have a pretty penny on your hands so when you ell them make sure you have a valuation certificate and are able to prove their authenticity.