The Pilgrim's Scallop Shell: A symbol of love...?

Today is Valentines Day. It also happens to be my birthday! The origin of St. Valentines Day and the saint's history are interesting in itself, but I thought I would look at another potential symbol for love: la concha, a vieira: the scallop shell.

There are many interpretations of the scallop shell as a symbol of the St. James' pilgrimage. We are told that, as the boat carrying the Apostle's body approached, a rider - sometimes a bridegroom - fell into the sea and emerged (through a miracle of St. James) covered in "vieiras". The scallop shell was also considered useful for pilgrims on the Camino de Santiago. It was the right size for gathering drinking water or for receiving scraps of food from the people along the way: a size so small that even the poorest could afford to give out of charity. It was also a symbol of the pilgrim him or herself, generally being worn on a "cockleshell" hat or sometimes sewn on the cape.

All this is all very well, but I have often wondered how pilgrims from say central Germany would have found such a shell. Perhaps there were itinerant shell sellers along the way. Perhaps I am a cynic...

It does make sense, however, if those walking on to Finisterre found their "badges of pilgrimage" at the end of their journey. This of course begs the question as to where the Camino de Santiago ends? The church would say at the Apostle's tomb; however, Compostela is many miles from the sea and shells would have been sold in the Azabachería just as they are today. But for the authentic Camino de las Estrellas experience, the pilgrim would have to journey on westward if s/he wanted to find a shell on the beaches of Finisterre or in the harbour where once they littered the sand.
So what about other options for the shell?

Rafael Lema in his wonderful book El Camino Secreto de Santiago, which I have just finished reading (slowly) claims a much earlier origin. And it is very convincing.

In Moraime on the Costa do Morte there was once a Benedictine monastery. Archaeological investigations have also found, on this site, remains of a Visigothic settlement, and a Roman necropolis. Amongst other things, two bronze scallop shells were discovered, dating from early Roman occupation of the Peninsula. They are evidence of the worship of Venus. This symbol, claims Lema, was converted into one of the Camino de Santiago, but its origins are clearly maritime, and pagan.

Along with the Venus Cult, the Romans, especially those from North Africa brought the Cult of Isis. Both are considered goddesses of love. The cathedral itself is built over a pagan site dedicated to Jupiter and I myself have seen, in a tiny church near Padron, a large stone marker on which the name of Mercury is inscribed. I have promised never to reveal where as the lady with the key didn't even know its significance but said that it must never go a museum. I agree.

The lines and grooves on the scallop shell are said to represent the meeting of all the roads to Santiago in Compostela; it is a nice image. However, the shell is also claimed to represent the setting sun; the rays off the horizon at the ends of the earth:
Finisterre.
.