1896-97-] The Upper Elf Loch, Braids. 279 



uneven in depth, and the bottoms of some of them are locally excavated 

 to such an extent that they form landlocked hollows, which are surrounded 

 on all sides by solid rock at a higher level. Where the surface soil 

 happens to be impervious water gathers, and these hollows are converted 

 into small tarns. 



The nature of the deposits left in these hollows is a matter of consider- 

 able interest to both biologists and geologists ; as, owing to the fact that 

 the tarns in question date from the close of the Glacial Period, we may 

 expect to meet in them with remains of the various faunas and floras that 

 have lived there from the close of the Glacial Period down to the present 

 day. 



The investigation of the geological deposits in this loch we 

 have been unable to take up, seeing this would probably entail 

 considerable labour, as draining and excavating, — though the 

 results, as Mr Goodchild remarks, might be of considerable 

 interest. Our attention has been confined to the living forms ; 

 and as these vary much from time to time throughout the 

 year, six visits have been made up to the present date — 

 viz., on May 2, July 18, and October 17 of last year (1896), 

 and February 6, March 6, and April 24 of this year. 

 Gatherings were taken on each occasion by means of a drag- 

 net, and small quantities of the water, with aquatic plants and 

 decaying vegetation, were also secured, for careful examination 

 by the microscope at home, and subsequent despatch to 

 specialists, as already mentioned. The gentlemen who have 

 thus kindly favoured us with their help are Mr John Hood, 

 F.E.M.S., Dundee, who is well known as an authority on the 

 Infusoria and Eotifera, and who rendered material assistance 

 to Mr Saville Kent and to Messrs Hudson and Gosse in their 

 respective manuals on these groups ; also our fellow-members, 

 Mr James Terras, B.Sc, assistant to Professor Bayley Balfour, 

 who is at present working out the filamentous alga? and con- 

 fervas of this loch, — groups with which he is well acquainted ; 

 and Mr P. H. Grimshaw, of the Museum of Science and Art, 

 who has carefully examined the aquatic insects. Our thanks 

 are very specially due to these gentlemen for the aid they have 

 rendered and are still rendering us. Mr W. C. Crawford and 

 Dr Davies, not to mention other members of the Society, have 

 also taken a great interest in the work being carried on here. 



Standing by the side of the Upper Elf Loch on a summer 

 day, a few familiar aquatic plants may be at once noted. 



