Seeing how the name of our project is taken from St. James the Greater, let’s begin there. Here’s a neat distillation of his apostolic life and death, taken from our friends at New Advent:
According to [sic] tradition, St. James the Greater, having preached Christianity in Spain, returned to Judea and was put to death by order of Herod; his body was miraculously translated to Iria Flavia in the northwest of Spain, and later to Compostela, which town, especially during the Middle Ages, became one of the most famous places of pilgrimage in the world. The vow of making a pilgrimage to Compostela to honour the sepulchre of St. James is still reserved to the pope, who alone of his own or ordinary right can dispense from it. In the twelfth century was founded the Order of Knights of St. James of Compostela.
And here’s something specific about the meaning of the shell, courtesy of Wikipedia:
The scallop shell is the traditional emblem of James, son of Zebedee, and is popular with pilgrims on the Way of St James to the apostle’s shrine at Santiago de Compostela in Galicia (Spain). Medieval Christians making the pilgrimage to his shrine often wore a scallop shell symbol on their hat or clothes. The pilgrim also carried a scallop shell with him, and would present himself at churches, castles, abbeys etc., where he could expect to be given as much sustenance as he could pick up with one scoop. Probably he would be given oats, barley, and perhaps beer or wine. Thus even the poorest household could give charity without being overburdened.
The association of Saint James with the scallop can most likely be traced to the legend that the apostle once rescued a knight covered in scallops. An alternative version of the legend holds that while St. James’ remains were being transported to Galicia (Spain) from Jerusalem, the horse of a knight fell into the water, and emerged covered in the shells. Indeed, in French the animal (as well as a popular preparation of it in cream sauce) is called Coquille St. Jacques. In German they are “Jakobsmuscheln”—literally “James mussels.”
The scallop shell is represented in the decoration of churches named after St James, such as in St James’ Church, Sydney, where it appears in a number of places, including in the mosaics on the floor of the chancel.
As for the sword going straight through the shell in the logo, this refers to our work in the New Evangelization, spreading the word of God.
For the word of God is living and active, sharper than any two-edged sword, piercing to the division of soul and spirit, of joints and marrow, and discerning the thoughts and intentions of the heart (Heb 4:12).