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CHAPTER VII. 
FOSSIL ZOOPHYTES.—PORIFERA OR AMORPHOZOA—-POLYPIFERA OR 
CORALS—BRYOZOA OR MOLLUSCAN ZOOPHYTES. 
Many tribes of the extraordinary beings whose mineralized 
relics are the immediate subject of our investigation, have 
largely contributed to the solid materials of which the sedi- 
mentary strata are composed. In the most ancient rocks 
in which vestiges of organic structures have been detected, 
those of Zoophytes hold a conspicuous place; and in the 
seas of tropical climates, the agency of the Coral-animalcules, 
or Polypifera, is producing enormous deposits, and laying the — 
foundations of new islands and continents, and forming reefs a 
of rocks hundreds of miles in extent, which, if elevated above _ 
the level of the sea, would rival in magnitude the mountain 
chains of modern Europe. 
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The reader unacquainted with the natural history of these — 
marvellous creatures will find an account of their nature and — 
economy, and of the physical effects produced on the earth’s — 
surface by their agency, in the sixth lecture of Wond. vol. ii. — 
p. 988. 
The term Zoophytes, or animal-plants, comprises two very F 
distinct classes of living beings, namely, the PorIFERA, or — 
Sponges, which (if not vegetables) are wanting in many attri- _ 
butes regarded as essential characteristics of the members of 
the animal kingdom ; and the Potypirera, or polype-bearing- < 
animals,—the Corals; which are generally associated groups 
or aggregations of individuals, united by a common organ- — 
