GLOSSARY. 921 



Trilobites an extinct family of Crustacea, the body divided into three 



lobes. 



Tubipora organ-pipe coral ; corals composed of tubes. 



Tufa calcareous deposit from incrusting streams. 



Tuff earthy volcanic rock. 



Turbinated top-shaped, inform of an inverted cone. 



Unconformable strata lyinsr in adifferent position tothose on which theyrest. 



Ungulata hoofed animals. 



Univalve shell composed of but one piece. 



Veins fissures in rocks, filled up by mineral substances. 



Vermes •worms. 



Vermiform worm-shaped. 



Vertebrated animals having a flexible, osseous, spinal column. 



Verticillate arranged in -whorls. 



Vesicular full of vesicles or cells. 



Villi processes in animal structures, resembling the pile of 



velvet. 



Vitrification the fusion of a substance into glass by heat. 



Viviparous bringing forth live young. 



Zeolite peculiar minerals found in volcanic rocks. 



Zoology the study of animals. 



Zoological relating to animals. 



Zoothytes animal-plants, a term applied to corals and other animals 



that resemble vegetables in form. 



