HILL: GEOLOGY OF THE ISTHMUS OF PANAMA. 285 



PLATE IX. 

 Along Panama Canal, Caribbean Side. 



PLATE X. 

 Panama Canal, cutting through Volcanic Tuff, at San Pablo. 



PLATE XL 



Culebra Basin, looking East. 



PLATE XII. 



Panama Canal, Summit Section at Culebra, looking South. 



PLATE XIII. 

 Panama Canal, cutting through Basalt, at Paraiso. 



PLATE XIV. 



Scene in the Valley of Cartago. 



PLATE XV. 

 Crater of Poas Volcano. 



PLATE XVI. 

 Boulder Clays, Rio Bevantazon. 



PLATE XVII. 



Boulder Clays, Rio Revantazon. 



PLATE XVIII. 



Tobago Island. 



PLATE XIX. 

 Crater of Turialba Volcano. 



