THE PAMPEAN PLAIN. THE RIO BAMBA (IN THE SOUTH OF THE 

 CORDOBA PROVINCE, 5OO FEET ABOVE SEA-LEVEL). 



Small circular lagoons. The underground water, which comes from the Sierras to the north- 

 west, here reaches the surface. Zone of lucerne farms. Photograph by the Author. 



THE PAMPEAN PLAIN. BUENA ESPERANZA (SAN LUIS PROVINCE, 

 1,166 FEET ELEVATION). 



The f>lain is sown with quick ond dead dunes, often shaped in a circle round a lagoon. A dune 

 invaded by vegetation. Photograph by the Author. 



PLATE XVI. To face p. 182. 



