1435 (14). 
PROCEEDINGS OF MONTREAL MEETING. 
Section of lava flow, El Pedregal of Tialpam, near San Angel, valley 
of Mexico. The vesiculation of the lava by escaping vapors is shown 
and the increase through relief of pressure in the size of the vesicles 
toward the upper surface. 
Three views photographed and presented by W. C. Stevenson 
Size, 35 by 43 inches 
1436. Cambrian limestone, Earnest Station, P. R. R., near Morriston, Pennsyl- 
vania. 
1437. Potsdam. sandstone exposure, Rhodes quarry, Edge Hill, Montgomery 
county, Pennsylvania. 
1438. Potsdam sandstone, Smith’s quarry, Edge Hill, Montgomery county, Penn- 
sylvania. 
Thirty-four views presented by the U. S. Geological Survey (C. D. Walcott) 
Size, 
1459 (345). 
1440 (349). 
1441 (350). 
1442 (363). 
1443 (3640). 
1444 (365). 
1445 (365¢). 
1446 (366). 
1447 (368). 
1448 (3740). 
1449 (375b). 
1450 (376). 
1451 (405). 
1452 (406). 
1453 (408). 
1454 (410). 
1455 (412). 
1456 (415). 
1457 (417). 
1458 (418). 
1459 (436). 
45 by 6} inches. Figures in parentheses are original numbers 
Summit of Conness peak, Yosemite National park, on Sierra divide, 
U.S. Coast and Geodetic station. 
Granite point near trail and glacial lake on Conness Peak trail, Yosem- 
ite National park. 
Granite showing effect of cleavage fractures in producing forms of 
erosion, Conness Peak trail, Yosemite National park. 
The dome above Nevada falls, Yosemite National park. 
Domes above Nevada falls, Yosemite National park. 
Liberty cap, above Nevada falls, Yosemite National park. 
Liberty cap, above Nevada falls, Yosemite National park. 
Fractures in granite at base of Liberty cap, Yosemite National park. 
Vernal falls, Yosemite National park. 
Cliffs above Mirror lake, Yosemite National park. ' 
North dome and cliff, Yosemite valley. 
The arches, Yosemite valley. 
View of pegmatite rocks on Sylvan lake 6 miles north-northeast of 
Custer, Black hills, South Dakota. 
View of pegmatite rocks on Sylvan lake 6 miles north-northeast of 
Custer, Black hills, South Dakota. 
View of pegmatite rocks on Sylvan lake 6 miles north-northeast of 
Custer, Black hills, South Dakota. 
View from the summit of Harney peak, Black hills, South Dakota. 
View from the summit of Harney peak, Black hills, South Dakota. 
View of eroded pegmatite rocks below the ‘‘ Needles,” in trail from 
Sylvan lake to Harney peak, Black hills, South Dakota. 
View of eroded pegmatite rocks below the “‘ Needles,” in trail from 
Sylvan lake to Harney peak, Black hills, South Dakota. 
View of eroded pegmatite rocks below the ‘‘ Needles,”’ in trail from 
Sylvan lake to Harney peak, Black hills, South Dakota. 
Big Horn mountains, Wyoming. View of eastward dipping Paleozoic 
rocks forming eastern summit and slope of the mountains southwest 
of Sheridan. 
