12. SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 
its first appearance in San Bernardino in 1895, and says it 
threatens there to be more troublesome than the mustard. This 
lettuce when eaten by cattle gives a disagreeable odor to the 
milk, to the great discomfort of the dairymen. On the other 
hand, it is a weleome food for poultry, turkeys being particu- 
larly fond of it. In 1904 I observed) in some pools of the Los 
Angeles River near Hynes large quantities of the water hya- 
einth, Piaropus crassipes, Britton, the pest of the Florida 
rivers. Mrs. Lawrence has specimens from the San Gabriel 
River. This had evidently been established here for a few 
seasons before we discovered them. The heavy floods of this 
season have probably washed them away; the lack of water 
will prevent them ever being troublesome. 
