Image of Chirocephalus marchesonii Ruffo & Vesentini 1957
The "Lago di Pilato" is a lake in a deep u-shaped valley below Monte Vettore, a mountain in the Italian Central Apennines. There are two basins that sometimes are connected. When I took the picture, in June 2007, the two basins were not connected. The two basins were connected in June 2009 (?), see this picture http://www.flickr.com/photos/33434902@N04/3624776024/ by Fabrizio Di Meo.