GLOSSARY. 



Tertiary Strata. " A series of sedimentary rocks, with char- 

 acters which distinguish them from two other great series of 

 strata, the secondary and primary, which lie beneath them." 



Testacea. " Molluscous animals, having a shelly covering. ,, 



Tepid. Warm. 



Thermal. Hot. 



Thin out. Strata which diminish in thickness until they dis- 

 appear are said to thin out. 



Trap — Trappean Rocks. Ancient volcanic rocks, composed 

 cf feldspar, hornblende, and augite. Basalt, greenstone, amyg- 

 daloid, and dolerite, are trap rocks. 



Travertin. " A concretionary limestone, hard and semi-crys- 

 talline, deposited from the water of springs." 



Tufa Calcareous. " A porous rock, deposited by calcareous 

 waters on exposure to air, and usually containing portions of 

 plants and other organic substances incrusted with carbonate of 

 lime."' 



Tufaceous. A texture of rock like that of tuff. 

 Tuff or Tufa. "An Italian name for a volcanic rock of an 

 earthy texture." 



U. 



Unconformable. See Conformable, 

 V 



Veins. Cracks and fissures in rocks filled with stony or me 

 tallic matter. Most of the ores are obtained from metallic veins. 



Z. 



Zoophytes. Coral sponges and other aquatic animals allied 

 to them. 



THE END, 



