(No Negative) . Crossing a 
Riacho. Las Palmas, Chaco, 
Argentina. 
July 20, 1920. 
B.S. 21992. Ferry across 
deep riacho. Las Palmas, Chaco, 
Argentina. 
July 30, 1920. 
* * 
B.S. 21993* A flycatcher 
Machetornis rixosa perched on a 
cow. Las Palmas, Chaco, Argentina. 
August 1, 1920. 
