Labrador feldspar, ejected.

Lakes at bases of volcanoes.

Lamination of volcanic rocks.

Land-shells, extinct, at St. Helena.

Lanzarote, calcareous beds of.

Lava, adhesion to sides of a gorge. -feldspathic. -with cells semi-amygdaloidal.

Lavas, specific gravity of.

Lava-streams blending together at St. Jago. -composition of surface of. -differences in the state of their surfaces. -extreme thinness of. -heaved up into hillocks at the Galapagos archipelago. -their fluidity. -with irregular hummocks at Ascension.

Lead, separation from silver.

Lesson, M., on craters at Ascension.