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Part III. — Thirteenth Annual Report 



Group II. — LOCHS ON THE MAINLAND. 



1st. Loch na Kbnna (or the Lilly Loch) near E. Tarbert, 

 Argyllshire. 



I now proceed to describe the second group of lochs — viz., those in the 

 Mainland — that have been examined during the past year ; and the first 

 I propose to refer to is a little hill loch called Loch na Kenna, and some- 

 times the Lilly Loch, from the number of white water lilies that grow in 

 it. It was examined in the month of July, and though minute organisms 

 such as Infusoria, Rotifera, Diatoms and other algae, &c, were abundant, 

 comparatively few Mollusca or Crustacea were obtained. The Mollusca 

 included two species of Pisidia and two of Limnse&, while the Crustacea 

 comprised two species of Copepoda and six species of Cladocera, none of 

 which are very uncommon. 



2nd. Lochs in Perthshire. 

 Lochan a Chaite (on Ben Lawers). 



This is a small loch situated fully half-way up the famous Perthshire 

 mountain so well known to botanists for the many rare alpine plants that 

 are to be obtained among its rocks and gullies. Lochan a Chaite occupies 

 a hollow in a kind of natural recess at the foot of the precipitous ridge of 

 rocks that extends from a little below the summit of Ben Lawers to the 

 mountain on the east side, apparently as if it were binding the two to- 

 gether. As the two mountain masses extend some distance forward in a 

 southerly direction, a kind of natural recess, as I have called it, is formed, 

 the mountain summits forming the sides, while the ridge encloses it on the 

 north ; the ground within this recess is comparatively flat, with the loch 

 near the middle. The nearest way to the loch is to 1 make a Bee line ' 

 right up and across the moor from Lawers Inn ; but an easier though 

 longer way is by the hill road that joins the highway a short distance 

 east from the Inn, and close beside the Lawers Burn, which is the effluent 

 from Lochan a Chaite. This hill road follows the track of the Burn, more 

 or less closely, nearly all the way up to the Loch. 



The water in the loch is supplied by the streamlets that drain off the 

 surface moisture from the adjacent sides of the two mountains, and which 

 during a great part of the year consists chiefly of rain water or melted 

 snow, or a mixture of both. The loch appears to be rapidly filling up with 

 the sediment carried into it by its affluents, and even as it is a large por- 

 tion of it is very shallow, so much so that a small tow-net with a ring 

 about 12 inches diameter, when dragged across the loch some distance up 

 from its lower end touched the bottom in several places, when part of the 

 ring was still appearing above the surface of the water. The deepest part 

 appears to be at the upper end, but I was unable at the time of my visit 

 to ascertain its depth here. 



The altitude of Lochan a Chaite is about 2400 feet above sea-level, 

 and over 2000 feet above Loch Tay. It was examined about the middle 

 of September. 



Because of the great altitude of this little loch, I considered that it was 

 just possible that organisms might be obtained in it that are not to be 

 found in lochs lower down. The examination of the gatherings collected 

 in September, however, does not seem to bear this out, for, with one or two 

 exceptions, all the species obtained are similar to those frequently ob- 

 served in lochs and pools within a few feet of the level of the sea. But 

 though the results were somewhat disappointing, I was rewarded by the 

 discovery of one organism — a Copepod quite distinct from any other 



