226 ANNALS OF SCOTTISH NATURAL HISTORY 



A CONTRIBUTION TO OUR KNOWLEDGE OF 

 THE FRESHWATER RHIZOPODA AND 

 HELIOZOA OF SCOTLAND. 



By JAMES MEIKLE BROWN, B.Sc., F.L.S. 



COMPARATIVELY little systematic work appears to have been 

 done on the distribution of the Freshwater Rhizopoda and 

 Heliozoa of Scotland. Penard and Murray published in 

 1905 a report on material collected by the Lake Survey 

 from Loch Ness; G. S. West, also in 1905, gave lists of 

 species found chiefly in plankton collections from the Orkney, 

 Shetland, and other outlying islands ; while Murray again 

 in 1907 and W. Evans in 1909 published lists of species 

 from the Forth Area. Beyond these papers, and scattered 

 references in Cash's monograph, no published results seem 

 to be available. 



It was with a view to commencing a more detailed 

 investigation that material was collected by the writer 

 during August and September of last year, from various 

 localities in Scotland ; and it was hoped that some species 

 hitherto unrecorded for this country might be found. This 

 hope has been justified by the results, and it is probable 

 that further work will yield still more interesting finds ; but 

 it will require much more extended observations before the 

 problems dealing with the general distribution of these 

 interesting animals can be solved. Further, it will be only 

 after a very careful study of the variations occurring amongst 

 the "species" and many seem to have a rather wide range 

 of variability that the limits of, and relationship between, 

 the different species can be definitely decided. At present 

 it is often very difficult or even impossible, especially in 

 some genera, to discriminate between species, unless the 

 individuals are quite " typical." This is particularly the case 

 amongst the Euglyphae, many small forms occurring which 

 at present defy the systematist. 



As it will probably be some time before further collec- 

 tions in other localities can be made, it has been thought 

 desirable to publish the results so far obtained. 



