View of Aegina Kolonna with (inset, left to right) a 16th-century drawing of a purple snail; Hexaplex trunculus; and a purple pigment sample. Aegina Kolonna excavation, Department of Classics, Paris Lodron University of Salzburg.S. Münster, Cosmographia, 1544; G. Forstenpointner; L. Berger
Many Aegeans dyed to bring us this information.
How are or were those snails collected?