362 J. LeConte on the great Lava-flood of the West, 
is covered universally, to a depth of five to thirty feet, with a 
very fine unsorted earth (a true rock-meal) mixed with lava 
pebbles ; the pebbles becoming larger and more numerous in the 
lower part. We may therefore roughly divide the whole 
thickness into two layers graduating into each other; a top 
only ac- 
count for the absence of glaciated surfaces by the rapidity with 
which lava undergoes surface disintegration. .I know of no 
Nore.—The reader will notice an error of 100 in the ing beyond, com- 
ing with this page.—F samt : paging beyon 
