BULL. GEOL. SOC. AM. 



VOL. 25, 1913, PL. 19 



Figure 1. — Pillowy Surfaces in ellipsoidal Greenstone of the Orca Group (Mesozoic) 



The lava flow lias been exposed by waves near Kocky I'oint, Pi-ince William Sound, 

 Alaska. Masses range from a few inches to 10 feet in diameter. Photograph from the U. S. 

 Geological Survey. Bulletin 44.>, phite viii-A. 



Figure 2. — Cross-section showing radial Jointing of the Pillows at the same Locality 



Masses range from a few inches to 10 feet in diameter. Photograph from the U. S. Geological 

 Survey. Bulletin 44M, plate viii-B 



PILLOW SURFACES OF ELLIPSOIDAL GREENSTONE AND CROSS-SECTION OF RADIAL 



JOINTING OF PILLOW LAVA 



