PLATE III. 



The largest of the Puna pit-craters in Hawaii. The plain is a frozen lava 

 lake, the bottom of which is indicated by the inked line. Beneath that mas- 

 sive lava is old talus material, exposed in the fault-scarp of the foreground, 

 which shows a maximum thickness of 60 meters for the lava prism. The con- 

 duit which fed this lake was probably at the deep hole overlooked by the fault 

 cliff of the middle foreground. The lava plain is about one kilometer in 

 length. 



