The paintings were stolen Aug. 5 by gunmen as a handful of visitors milled about the museum in Nice. The stolen paintings were Monet’s 1897 “Cliffs near Dieppe,” the 1890 “Lane of Poplars near Moret” by fellow Impressionist Alfred Sisley and Flemish master Jan Brueghel the Elder’s 17th century “Allegory of Earth” and “Allegory of Water.” Together, they are worth about $1.55 million.