68 
ROOM XI. 
Nat. Hist, 
Most of the Zoanthariae form a calcareous covering, 
called coral, into which they can withdraw themselves from 
external danger. This coral consists of a congeries of 
cells which are inhabited by the animals, and are formed 
of laminae radiating from a centre, so as to give the cavity 
a stelliform appearance. Corals are generally attached 
to marine bodies during the whole of their growth, 
but some few, as the Sea Mushroom (. Fungia ), and 
the Sea Slug {PolyphyIlia), only when young, and by 
a short stem; as the coral enlarges, the crown separates 
from the stem by a natural absorption, and, at length, 
is left quite free. 
The reefs and islands, which are constantly forming 
in certain seas, especially the Pacific Ocean, are the 
work of the minute animals which inhabit these kinds 
of corah 
Table Case No. 1, contains the following genera, be- 
longing to the class Zoantharia:—Cyclolites, and Fungia. 
No. 2. Polyphyllia—Turbinolia—Caryophyllia—Sar- 
cinula—Catenipora—Dendrophyllia, and Lobophyllia. 
No. 3, Meandrina* and Agaricia—a portion of the 
latter are in No. 4. 
No. 4. Tridacophyilia—Monticularia—and Pavonia, 
No. 5. Astraea, and Echinastraea. 
No. 6. Oculina—Dentipora—Astreopora, and Gem- 
mipora. 
No. 7 and part of 8, Madrepora. 
No. 8. Palmipora—Heliopora—Alveopora—Gonio- 
pora—Porites—Seriatopora—Pocillopora, and Antho- 
pora ( Gray ) ; 
The animals of the class Polypiaria, differ from the 
Sea Anemones, and the Zoanthi, by the mouth being 
provided with only a single series of long tentacula, by 
the body being more slender, and by the cells which they 
form being quite simple, or without any radiating laminae. 
* On a Table, in front of the middle window, is a remarkably fine 
specimen of the Meandrina cerebriformis, from Bermuda, presented 
by the late Dr. Jarvis, of Margate. 
The 
