No. 200,] 
879 
Littoral, of, or belonging to, the shore. 
Loam. A mixture of sand and clay. 
Mural Esca)'pment. A rocky cliff, more or less inclined. 
Mamraillary. Protuberances on the surface of a mineral, which are seg' 
menls of a sphere; mamma?, breasts. 
Mtmmoth. An extinct species of animal, allied to the elephant. 
Marl. Any mixture of clay and carbonate of lime, which effervesces 
with acids. 
Matrix. Gangue. The mineral mass which is in immediate contact with 
the ore of a metal, both of which constitute a vtin. 
Manganese. A hard bhick mineral, resembling the dark coloured hema- 
tites. It is the oxide of manganesium, one of the metals. 
JMegatkerium. One of the extinct fossil quadrupeds, resembling the sloth. 
Mechanical origin of^ Rocks composed of sand, pebbles, &c. cr sedi- 
mentary rocks generally, are said have a mechanical origin. The 
term is used in contradistinction to rocks having a crystalline struc- 
ture, which have a chemical origin. 
Mica. Sometimes called isinglass. A mineral, which may be split in- 
to numerous elastic lamina). 
Mica slate. A primary rock, composed of fine grains of quartz, and ge- 
nerally small scales of mica. It is eminently fissile. 
Miocene. An era or period subsequent to the eocene, and characterized 
by a greater proportion of animals analogous to those now living. 
Deposits formed during this period are termed miocene strata. 
Molusca. Moluscous animals. Those soft animals, whose covering is a 
thick shell, as oyster and clam. 
Monocctyledoncus^ One of the grand divisions of the vegetable kingdom. 
It includes the grasses, palms, liliaccJE, and whose seed have only one 
lobe. 
Mountain limestone. A series of limestone strata immediately below 
the coal measures. 
Muriate of Soda. The chemical name for common salt, because it is 
composed of muriatic acid and soda. 
Jfa'phtha. A very thin volatile, inflammable liquid, of which there are 
springs in some volcanic districts. 
JSl'ew Red Sandstone. A serious of sandy, argillaceous, and often calcare- 
ous strata, whose predominant colour is brick red, but contains many 
spots and stripes, which are grtiy and greenish gray. It is therefore 
sometimes called the variegated sandstone. It overlies the coal mea- 
sures. 
JVucleus. A solid central piece, around which layers of the same or other 
matter has collected. The kernel. 
Old Red Sandstone. A rock belonging to the carboniferous group. 
Oolite. Oolitic. A limestone composed of rounded grains, like the roe 
or eggs of fish. The name is applied to a large group of strata, cha- 
racterized by peculiar fossils. Only a part have this peculiar structure, 
Orthocera^ ort/ioceratite. An extinct genus of animals belonging to the 
order Mollusca. They inhabited long straight tapering shells, divided 
into parts by septa or partitions. Common in the transition or Tren- 
ton Falls limestone. 
Outcrop. The edges of strata, as they appear at the surface. 
Outliers. The detachment of a mass of rock from the general formation 
