Megalichthys. Megas, great; ichthus, fish.
Metamorphic Rocks. Rocks that have undergone change or metamorphosis since their original formation.
Metatarsal. The part of the foot between the ankle and toes.
Meteorology. The science of the phenomena of the atmosphere.
Mica slate. Is the lowest stratified rock except gneiss—it is unfossiliferous.
Miocene. The middle of the three divisions of tertiary rocks, according to Sir C. Lyell.
Molasse. A provincial name for a sandstone associated with marl and conglomerates, found abundantly in the great valley of Switzerland. It belongs to the middle tertiary period.
Molecules. The ultimate particles or atoms of bodies.
Mollusca. A division in Conchology.
Monomyaria. Bivalve shells having but one adductor muscle.