66 GLOSSARY. 



CRETACEOUS. Belonging to chalk. Elym., Creta, chalk. 



CROP OUT. A miner's or mineral surveyor's term, to express the 

 rising up or exposure at the surface of a stratum or series of 

 strata. 



CRUST OF THE EARTH. See Earth's crust. 



CRUSTACEA. Animals having a shelly coating or crust which they 

 cast periodically. Crabs, shrimps, and lobsters are examples. 



CRYPTOGAMIC. A name applied to a class of plants in which the 

 fructification, or organs of reproduction are concealed. Etym., 

 Kpvn-Tos, kryptos, concealed, and ya/zoe, gamos, marriage. 



CRYSTALS. Simple minerals are frequently found in regular forms, 

 with facets like the drops of cut glass of chandeliers. Quartz 

 being often met with in rocks in such forms, and beautifully 

 transparent like ice, was called rock-crystal, ^voraXXoc, crys- 

 tallos, being Greek for ice. Hence the regular forms of other 

 minerals are called crystals, whether they be clear or opake. 



CRYSTALLIZED. A mineral which is found in regular forms or crys- 

 tals, is said to be crystallized. 



CRYSTALLINE. The internal texture which regular crystals exhibit 

 when broken, or a confused assemblage of ill-defined crystals. 

 Loaf-sugar and statuary-marble have a crystalline texture. 

 Sugar-candy and calcareous spar are crystallized. 



CYCADE.E. An order of plants, which are natives of warm climates, 

 mostly tropical, although some are found at the Cape of Good 

 Hope. They have a short stem, surmounted by a peculiar 

 foliage, termed pinnated fronds by botanists, which spreads in 

 a circle. The growth of these plants is by a cluster of fresh 

 fronds shooting from the top of the stem, and pushing the 

 former fronds outwards. These last decay down to their bases, 

 which are broad, and remain covering the sides of the stem. 

 The term is derived from jcv/tae, cycas, a name applied by the 

 ancient Greek naturalist Theophrastus to a palm, said to grow 

 in Ethiopia. 



CYPERACEA. A tribe of plants answering to the English sedges ; 

 they are distinguished from grasses by their stems being solid 

 and generally triangular, instead of being hollow and round. 

 Together with graminece they constitute what writers on bota- 

 nical geography often call glumaceas. 



DEBACLE. A great rush of waters, which breaking down all opposing 

 barriers, carries forward the broken fragments of rocks, and 

 spreads them in its course. Etym., debacler, French, to unbar, 

 to break up as a river does at the cessation of a long-continued 

 frost. 



