These two plan views of the dolmens known as the Table des Marchands and the Dolmen des Pierres plates, in the commune of Locmariaquer (Morbihan), were produced by Louis Galles, a member of the Société polymathique du Morbihan. His cousin was René Galles, director of the musée archéologique de Vannes and a correspondent of the commission from 1865. Together they carried out excavations of different burial mounds in Brittany and supported the commission’s work.