To say that we saw a lot of scallop shells would be a vast understatement. As I mentioned, the yellow arrow and scallop shell are the main markers along the Camino.

Shells seen in the sidewalks along the Camino
I have previously posted some of the markers that had an arrow and shell:

Only 160.9 km to go!
These were the largest shells I saw:

Man-eating shell

Church in Arca
We saw shell tiles for sale and shells used as home decorations; we each carried shells on our packs.

Marylynn’s backpack the night before we started our hike
The following is from Caminoways.com
There are many stories that try to explain the link between the scallop shell and the Camino. The lines of the scallop shell are said to represent the different routes pilgrims travel from throughout Europe (and Asia), all walking trails leading to the tomb of Saint James in Santiago de Compostela.
Medieval pilgrims often wore a scallop shell attached to their cloaks or hats during their journey to Santiago. More than being just a symbol or a pilgrim badge, the scallop shells also had a practical purpose: they were a handy and light replacement for a bowl so the pilgrims could use them to hold their food and drink on their long journey. Pilgrims would also be given food at churches and other establishments, and a scallop shell scoop was the measure for the food they would be donated.
Since the scallop is native to the coast of Galicia, the shell also became a memento, a physical proof of having completed the pilgrimage to Santiago, which often included the walk to Fisterra (the “End of the Earth”). The shells could be picked up at the very end of the journey in Fisterra but also became a popular souvenir and source of business for the shops near the Cathedral in Santiago.
In her book, “Walk in a Relaxed Manner”, Joyce Rupp talks about the shells (and arrows) as symbolic of various activities in our lives that keep us in the Now. Father Michael compared the shells to the helping hands (that we should accept) as we go along our “way.”
For me, the shells are symbolic of God’s presence in our lives. Sometimes God is very obvious; sometimes we can pass right by without even recognizing God. Sometimes God is providing direction; at other times help in a time of need.