Glossary. 
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Limestone. Ordinary calcium carbonate. 
Magnetite. Magnetic iron ore. (Fe 3 O t ). 
Marble. A rock formed, properly speaking, wholly, or 
almost wholly, of crystalline carbonate of lime, differ- 
ing from ordinary limestone in being crystalline with a 
texture often resembling loaf-sugar. Popularly, the 
word is often extended to include any limestone which 
will take a polish. 
Marsupialia (Lat. marsupium , a pouch). An order of 
Mammals in which the females have with few excep- 
tions an abdominal pouch in which the young are 
carried. 
Mastodon (Gr. mastos , a nipple ; odons, a tooth). An 
extinct genus of elephantine mammals. 
Mesozoic (Gr. mesos , middle ; zoe , life). The Secondary 
or middle period in Geology. 
Mica. A group of minerals of “ platy ” habit, with a 
metallic lustre ; some light, some dark in colour. 
Microlestes (Gr. mikros , little ; lestes , a thief). An extinct 
genus of Triassic mammals. 
Miocene (Gr. melon , less ; kainos, new). The middle 
Tertiary period, in which recent or living species of 
mollusca were less in number than species now extinct. 
Mollusca (Lat. mollis , soft). The sub-kingdom which in- 
eludes the shell-iish proper, the Polyzoa, the Tunicata, 
and the lamp-shells ; so called from the generally soft 
nature of their bodies. 
Neuroptera (Gr. neuron , a nerve; pteron , a wing). An 
older of Insects characterised by four membranous 
wings with numerous reticulated nervures (e.y., Dragon- 
