Vol. 62.] TAENS OF THE CANTON TICINO. 173 



down to Lago Cadagno, an outcrop of black hornblende-schist 

 occurs. The rocks forming the shores of the lake are jagged and 

 broken, and show no signs of ice-abrasion. The cliff of gneiss above 

 the northern and eastern shores is interrupted and broken down 

 towards the north-west, where a low col leads over into the Yal 

 Cadlimo. The lowest point of this col lies some 150 feet above the 

 present level of the lake. Another, but less well-marked depression, 

 leads from the spring on the north-western shore to a small pool, 

 which drains into the Lago Lisera in the Yal Cadlimo. 



Lago Taneda is, therefore, situated as nearly along the watershed 

 as may be, and it is probable that it drained at some former time over 

 one or both of these gaps into the Val Cadlimo ; possibly during a 

 temporary obstruction at the present outlet, or before it had been 

 cut down to its present depth. 



The greatest length of the lake from east-south-east to west- 

 north-west, along the line of strike, is 490 yards ; and the greatest 

 depth is 140 feet, practically the same as that of Lago Scuro. The 

 bathymetrical chart (PI. XX) shows that the greatest depression 

 is situated towards the western end of the lake, while the narrower 

 south-eastern end forms a shallow bay. There is, however, a 

 general axis of greatest depth running along the length of the lake 

 parallel to the strike of the rocks, which probably coincides with 

 the junction between the gneiss and the schistose rocks. 



Lago diMurinascio, alone among the tarns in this district, is 

 situated wholly in one set of beds. It lies at a height of 7562 feet, 

 and occupies a corrie in the northern wall of the Val Piora, above the 

 Murinascio Alp. It belongs to the upper group of lakes represented 

 by Lago Taneda and Lago Scuro. The lake is not entirely rock- 

 bound, the water at the lower end being held up by scree-material. 

 JSo soundings were made, as this lake is not a true rock-basin, and 

 there is no exit, A ridge of rock, however, forms the shore on the 

 south side, and it may possibly be a shallow rock-basin. 



Lago Lucomagno, situated in a corrie on the south-western 

 flank of the peak of that name, is partly scree-dammed, but must be 

 a rock-basin some 40 feet deep. It drains directly into the Ticino 

 below Varengo. but in this case, as in that of Lago Tom, there is no 

 overflow. A spring (which issues some 500 feet below) appears, 

 however, to derive its supply from this lake. The lake is almost 

 divided into two separate sheets of water by a narrow peninsula. 

 The water at the lower end is partly held up by rock-falls and screes, 

 and partly by rock in situ, and is situated along a strike-ledge in 

 the gneiss. The depression which the lake occupies can be seen 

 continuing as a line of weakness to the east, where it is weathered 

 out into a gully in the hillside. 



A little tarn, not shown on the Government map, occurs on the 

 northern slope of the same mountain, but it is obviously due to a 

 landslip, and does not require our further attention. 



Q. J. G. S. No. 246. o 



