No. 276.] 
346 
Littoral f of, or belonging to, the shore. 
Loam. A mixture of sand and clay. 
Mural Escarpment A rocky cliff, more or less inclined. 
Mammillary, Protuberances on the surface of a mineral, which are seg- 
ments of a sphere; mammas, breasts. 
Mammoth. 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 vein. 
Manganese. A hard black mineral, resembling the dark coloured hema- 
tites. It is the oxide of manganesium, one of the metals. 
Megatherium. One of the extinct fossil quadrupeds, resembling the sloth. 
Mechanical origin of^ Rocks composed of sand, pebbles, &c. or sedi- 
mentary rocks generally, are said to 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 into 
numerous elastic laminae. 
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. 
Monocotyledonous, One of the grand divisions of the vegetable kingdom. 
It includes the grasses, palms, liliaceae, 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. 
JYaphtha. A very thin volatile, inflammable liquid, of which there are 
springs in some volcanic districts. 
JVew Red Sandstone. A series of sandy, argillaceous, and often calca- 
reous strata, whose predominaiit colour is brick red, but contains 
many spots and stripes, which are gray and greenish gray. It is 
therefore sometimes called the variegated sandstone. It overlies the 
coal measures. 
^Nucleus. 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 offish. The name is applied to a large group of strata, cha- 
racterized by peculiar fossils. Only a part have this peculiar structure. 
Orthocera^ orthoceratite. An extinct genus of animals belonging to the 
order MoUusca. They inhabited long strait 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. 
[Assem. No, 275.] 44 
