74 
GLOSSARY. 
Mesotype. A simple mineral, white, and needle-shaped, one of the 
Zeolite family, frequently met with in the trap rocks. 
Metamorphic Rocks. For an explanation of this term, see vol. iii. 
p. 374. 
Mica. A simple mineral, having a shining silvery surface, and 
capable of being split into very thin elastic leaves or scales. 
It is often called talc in common life, but mineralogists apply 
the term talc to a different mineral. The brilliant scales in 
granite are mica. Etym., mico, to shine. 
Mica-Slate, Mica-Schist, Micaceous Schistus. One of the lowest 
of the stratified rocks, belonging to the primary class, which is 
characterized by being composed of a large proportion of mica, 
united with quartz. 
Miocene. See an explanation of this term, vol. iii. p. 54. 
Molasse. A provincial name for a soft, green sandstone, associ- 
ated with marl and conglomerates, belonging to the Miocene 
tertiary period, extensively developed in the lower country of 
Switzerland. See vol. iii. p. 212. 
Mollusc, Molluscous Animals. Animals, such as shell-fish, which, 
being devoid of bones, have soft bodies. Etym., mollis, soft. 
Monitor. An animal of the saurian or lizard tribe, species 
of which are found in both the fossil and recent state. 
Monocotyledonous. A grand division of the vegetable kingdom, 
founded on the plant having only one cotyledon, or seed-lobe. 
Etym., jjLovog, monos, single. 
Moschus. The quadruped resembling the chamois or mountain- 
goat, from which the perfume musk is obtained. 
Mountain Limestone. A series of limestone strata, of which the 
geological position is immediately below the coal measures, and 
with which they also sometimes alternate. See Table II. L, p. 393. 
Moya. A term applied in South America to mud poured out from 
volcanos during eruptions. 
Muriate oe Soda. The scientific name for common culinary salt, 
because it is composed of muriatic acid and the alkali soda. 
Musace.e. A family of tropical monocotyledonous plants, including 
the banana and plantains. 
Muschelkalk. A limestone which, in geological position, be- 
longs to the red sandstone group. This formation has not yet 
been found in England, and the German name is adopted by 
English geologists. The word means shell-limestone : miischel, 
shell, and kalkstein, limestone. See Table II. K, p. 392. 
Naphtha. A very thin, volatile, inflammable, and fluid mineral 
