368 GEOLOGICAL SURVEY OF CANADA. 



641. ARIS/EMA. 



(2400.) A. Dracontium, Schott. ; Macoun, Cat. IV., 72. 



On a flat in Delaware Township near London, Ont. 1889. (Mr. H. 

 D. Johnson.) On an island in the Sydenham Eiver, near Strathroy, 

 Ont. (Dearness.) 



642. PELTANDRA. 



(2407.) P. undulata, Eaf. ; Gray, Man., ed. VI., 72. 

 P. Virginica, Macoun, Cat IV., 72. 



Very local in its distribution. Should be looked for in western 

 Ontario. 



647 LEMNA. 



A species of this genus resembling tipirodela polyrrJiiza in color, but 

 having the -general appearance of L. minor, and with more than one 

 root was common in ponds at Agassiz, B.C., May 20th, 1889. For 

 the present this form must remain without a name or number. 



795. SPIRODELA, Schleiden. 



(2414.) S. polyrrhiza, Schleid. ; Gray, Man., ed. VI., 552. 

 Lemna polyrrldza, Linn. ; Macoun, Cat. IV, 75. 



In still water at Sicamous, Agassiz, and Port Haney, B.C. 1889. 



(Macoun.) 



648. WOLFFIA. 



(2415.) W. Columbiana, Karsten; Macoun, Cat. IV., 7fi. 



In a bay of Lake Ontario, west of Niagara Town, in company with 

 W. Brasiliensis, Weddell. 1889. (Dearness.) 



650. SACITTARIA. 



(241 S.) S. variabilis, Kngelm. ; .Mar-oun, Oat. IV., 77. 



Abundant in the South Thompson 'River at KamloopH, B C. 1888. 

 (Dflwson.) In marsh}' spots subject to tide action along the lower 



