PREFACE. 



The unfinished MS. and notes on the Heliozoa left 

 by Cash have been kindly placed at my disposal and 

 are utilised so far as possible, but his records are not 

 numerous, and only one or two drawings were available; 

 I am also indebted to the late Prof. G. S. West and to 

 Mr. J. M. Brown for original drawings and records. 



Unfortunately, during my examinations of British 

 gatherings for Rhizopoda, the occurrences of Heliozoa 

 were not specially noted, as it was anticipated that the 

 authorship of the present volume would have been 

 entrusted to more able hands. 



Since that time, absence abroad until the outbreak 

 of war, and then war-work together with travel 

 restrictions in England, have prevented the collection 

 of more than a few new records ; this is the more to 

 be regretted as there is in the Heliozoa a wide and 

 almost unworked field open to investigation so far as 

 their occurrence and distribution is concerned, and 

 the life-histories of the majority of the species are 

 still unknown. 



The descriptions of the species not yet recorded as 

 occurring in the British Isles are not properly within 

 the scope of the present volume ; but on account of 

 their number and the likelihood that they may be 

 recorded as British in the near future, their chief 



