BULL. GEOL. SOC. AM. 



VOL. ^5, 1913, PL. 20 



Figure 1. — Pillow Lava 



Showing eoncenti-ic layers of ainygdules and calcite filling tlie interstices between the 

 pillows. The locality is Pentire Head, St. Minvei-, north coast of Cornwall, England. Photo- 

 graph from the Geological Survey of Great Britain. 



Fkuire 2. — Pillow "DiahasI' 



The locality is on the shore 2 1/.^ miles south of Ballantrae, Ayrshire, Scotland. I'hotograpb 

 from the (Joological Survey of Great Britain 



PILLOW LAVA AND PILLOW "DIABASE" 



