Sant Iago by his cocklehat

• Santiago: pilgrims going to St. James' cathedral (Santiago de Compostela in Spain) wore a scallop shell (cockleshell) on their hats.

• cockle hat: from one of Ophelia's mad songs (Hamlet, Act IV, scene 5):  

How should I your true love know

From another one?

By his cockle hat and staff,

And his sandal shoon.