The burn is the Allt Coir a' Ghiubhsachain, but the chance of spelling correctly are so remote I didn't put it in at the time. I got a boot full of water crossing it, and Sail Liath behind me was too misty to photograph.
Moderate sized stones, a reasonable gradient and even some grass give welcome relief from the steep rock strewn slope which must be tackled to get to this point.
The ridge leading on from Sail Liath. Stob Cadha Gobhlach on the left is the next summit encountered, followed by the grim ramparts of Corrag Bhuidhe on the right. In the distance is Sgurr Creag an Each, the summit of the west ridge of Sgurr Fiona.
The ridge is not exactly the easiest to walk with much loose rock. Note the (black) figure in the far distance to give scale. A lone walker heading uphill.
Loch Toll an Lochain = Loch of toll an lochain = loch of the hole of the little loch.
I would imagine the OS informant didn't know any particular name for this loch, but he or she did know Toll an Lochain as a (not very interesting) name for the depression it sits in, and when pressed called the loch Loch of that.