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 he 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 
of 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, 
Y 
Veins. Cracks and fissures in rocks filled with stony or me- 
tallic matter. Most of the ores are obtained from metaUic veins. 
Z. 
Zoophytes. Coral sponges and other aquatic animals aUied 
to them. 
THE END. 
