68 
ROOM XI. 
Nat. Hist. 
The Zoanthi resemble the preceding, but the body 
is protected by a hard, coriaceous case into which it 
contracts when at rest. Most of these sheaths are 
united together by a common base, varying in form in 
the different genera. 
Most of the Zoantharise 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 laminss 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 (. Polyphyllia ), 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 coral. 
Table Case No. 1. contains the following genera, 
belonging to the class Zoantharia:—Cyclolites, and 
Fungia. 
No. 2. Polyphyllia—Turbinolia—Caryophyllia—Sar- 
cinula—Catenipora—Dendrophvllia, and Lobophyllia. 
No. 3. Meandrina* and Agaricia—a portion of the 
latter are in No. 4. 
No. 4. Tridacophyllia—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- 
* 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. 
pora 
