8 Weiss, Alien Aquatic Plants in the RcddisJi Canal. 



established themselves more or less successfuU)' in the 

 canal in the following order : — 



PithopJwra oedoi^onia, stations I to i8 (inclusive). 

 Chara /h-aiinii, i to 7, and 13 to 14. 

 Vnllisneria spiralis, stations 4 to 7, 12 and 13. 

 Conipsopogon sp., 4, 3 to 6 (inclusive). 

 Naias graviinea has apparently disappeared, or is at 

 all events, much reduced in amount. 



