CLITUMNUS, a river in Umbria, Italy, rising from an abundant spring by the road between the ancient Spoletium and Trebia, 8m. from the former, 4m. from the latter. After a short course through the territory of Trebia it joins the Tinia, a tribu tary of the Tiber. Pliny described and Caligula and Honorius visited the lake, which is still a clear pool surrounded by poplars and weeping willows. The stream was personified as a god, whose ancient temple lay near the spring; close by were other smaller shrines and it occurs under the name Sacraria (the shrines) as a Roman post station. The building, generally known as the Tempio di Clitunno, close to the spring, is an ancient Christian chapel, its decorative sculptures being contemporary with those of S. Salva tore at Spoleto (4th century)•