BULt. GEOL. SOC. AM. 



VOL. 25, 1913, PL. 21 



Figure 1.- — Pillow Lava 



Showing concentric arrangement of vesicles and interstitial limestone, 3 miles southwest of 

 Tayvallich, Argyll, Scotland. 1 hotograph from the Geological Survey of Great Britain 



Figure 2. — Longitudinal and transverse Sections of Pillow Lava 



Showing concentric arrangement of vesicles. The exposure is near North Ardbeg, Argyll, 

 Scotland, Photograph from the Geological Survey of Great Britain 



PILLOW LAVA FEATURES 



