of the Fishery Board for Scotland. 



169 



A few Mollusca were also obtained, i.e., Pisidium sp., Planorbis com- 

 planatuSj Planorbis nautileus, Planorbis contortus, Physa fontinalis, and 

 Limncjea peregra. 



The smallest number of Entomostraca observed in any of the gatherings 

 was in the one collected in June ; in this gathering the number observed 

 amounted to sixteen ; and the largest number, which was twenty-eight, 

 was obtained in the gathering collected in September 1897. 



The annexed formula shows the number of species belonging to each 

 of the three groups of Entomostraca observed in the various shore 

 gatherings; the following are the abbreviations used: — Co., Copepoda ; 

 Os., Ostracoda ; CI., Cladocera. 



Dates, .... 



Sept. 1, 

 1897. 



Dec. 15, 

 1897. 



March 2, 

 1898. 



June 15, 

 1898. 



Sept. 16, 

 1898. 



Names of the Groups, - 



Co. Os. CI. 



Co. Os. CI. 



Co. Os. CI. 



Co. Os. CI. 



Co. Os. CI. 



Number of Species in each 

 Group, 



14 4 10 



10 7 9 



9 11 4 



8 5 3 



8 7 3 



Number of Species in each 

 Gathering, 



28 



26 



24 



16 



18 



(8) Loch Doon, Ayrshire. 



Loch Doon, which is situated among the hills between Kirkcudbright- 

 shire and Ayrshire, and close to the boundary line that divides these two 

 counties, has an elevation of about six hundred and sixty feet above the 

 sea. The north end of the loch is very nearly three miles in a direct line 

 from Dalmellington — the place nearest to the loch to which the railway 

 has yet penetrated ; its overflow water finds an exit at this end and 

 forms the River Doon. The river, immediately on issuing from the loch, 

 flows with a rapid current down through Ness Glen — one of the 

 finest glens in the West of Scotland. According to the reduced 

 Ordnance Survey map of the district, Loch Doon extends for about two 

 and a half miles from the north end in a nearly south-east by south 

 direction, and then bends round to about south by west for other three 

 miles. Its breadth varies from about a quarter to nearly half a mile, 

 except at the " Ford of Moak " — a moderately large bay on the east side, 

 near where the loch bends round to the westward ; at this place the loch 

 is nearly a mile wide. Most of the lower half of the loch is shallow, but 

 the upper half (which 1 did not visit) is said to be deeper. The greatest 

 depth I obtained was forty-one feet, which was in March, when the 

 loch was rather above its usual summer level. 



The loch was visited on 16th September and 10th December 1897, and 

 on 31st March and 6th July 1898. On the occasion of the December 

 visit the weather was somewhat stormy, and shortly after commencing the 

 usual tow-net experiments the wind began to increase in force, and, as it 

 was from the south-east, and therefore nearly straight down the loch, the 

 water became so roup;h that the tow-net work had ere long to be given 

 up, and more time was therefore devoted to shore examination, but this 

 also did not give very satisfactory results. It has also to be noted that 

 the loch at this time was in flood, the water being so much above its 



