THE FRESH- WATER LOCHS OF SCOTLAND. 207 



These temperatures show a range of 12*5 from the surface to 100 

 feet, with a small inversion of half a degree between 100 and 140 feet. 

 About 3 p.m. the surface temperature in the centre of the loch, half 

 a mile from the east end, with a strong westerly breeze blowing, was 

 found to be 61-4. 



Loch an Xostarie (see Plate XLV.). Loch an Nostarie is a small 

 loch lying about a mile to the north of the west end of Loch Morar, 

 into which it drains through the little Loch a' Bhada Dharaich and 

 the Allt an Loin. It was surveyed on July 16, 1902, when, by 

 levelling from an Ordnance Survey bench-mark, the level of the water 

 surface was found to be 89-3 feet above sea-level. The loch has a length 

 of a little over half a mile, with a maximum breadth of nearly half a 

 mile, the mean breadth being a quarter of a mile. The area covered 

 by water extends to 90 acres, or nearly one-seventh of a square mile. 

 The number of soundings taken was 62, the maximum depth being 35 

 feet, while the mean depth is very nearly 11 feet. The volume of water 

 contained in the loch is estimated at 44,000,000 cubic feet, and the 

 drainage area extends to 1152 acres, or If square miles. The loch is 

 quite simple in conformation, the deep water occupying a central 

 position. 



Temperature Observations. On the date of the survey the tem- 

 perature of the water was found to be almost uniform from surface 

 to bottom, the difference between the surface temperature and that at 

 30 feet being only 0> 1 Fahr., as shown by the following series taken at 

 4 p.m. in the deepest part of the loch : 



Surface 59 '3 Fahr. 



10 feet 59-3 



20 59-2 ,, 



30 59-2 



The details regarding the lochs in the Morar basin are given in the 

 table on p. 208. 



NOTES ON THE BIOLOGY OF LOCH MORAR. 

 By JAMES MURRAY. 



Salmon, sea-trout, and loch-trout abound in Loch Morar, and the 

 sport is frequently very good, but the salmon as a rule are " dour " 

 to rise. Charr and the powan, or fresh-water herring (Cor eg onus), are 

 said to inhabit the loch. 



The biology of Loch Morar offers several peculiarities as compared 

 with most of the other large Scottish lochs. The quantity of plankton 



