CYCLOPEAN MASONRY, a term in architecture, used in conjunction with Pelasgic, to define the rude polygonal masonry employed by the Greeks, the Etruscans and other primitive peoples (from the Cyclopes, the supposed builders of the walls of Mycenae). In the earliest examples it consists only of huge masses of rock, of irregular shape, piled one on the other and depending on their great size and weight for cohesion ; sometimes smaller pieces of rock filled up the interstices. The walls and gates of Tiryns and Mycenae were thus constructed. Later, these blocks were shaped to fit one another. The date cannot always be de termined by the type of construction; where stratified rocks were obtainable horizontal coursing may in some cases have been early adopted; in fact, there are instances in Greece of a later wall of cyclopean construction being built over one with horizontal courses.